JPH10335140A - Electromagnet drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnet drive device in which an electromagnet is rapidly turned off at will and the electromagnet is not turned off by mistake. SOLUTION: An electromagnet drive device comprises a switching element 1 which is connected to a coil 3 of an electromagnet in series, a pulse signal generation circuit 16 which turns on the switching element 1 at a specified period, a regenerative circuit 4 which sends regenerative current to the coil 3 of the electromagnet, when a switch part is turned on. The switching element 1 is turned off from the condition in which the switch part is on, the switching element 1 is on, and a supply voltage is applied to the coil 3 of the electromagnet, and rapidly decreases the regenerative current sent to the coil 3 of the electromagnet with a power-absorbing element, when both the switch part and switching element 1 are turned off. Then a delay circuit 11 which turns on the switch part by applying a supply voltage and keeps the switch part on, until a specified time after stopping application of the supply voltage passes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnet driving device for driving a relay for controlling on / off of power supply to a load in an electric vehicle or the like.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to FIGS. FIG. 17 is a circuit diagram showing a configuration of a conventional electromagnet driving device. FIGS. 18A and 18B are timing charts of the electromagnet driving device. FIG. 18A shows the state of the switch in the ON state, FIG. 18B shows the state of the pulse signal, FIG. 18C shows the state of the current flowing through the coil, and FIG. The state is shown. FIG. 19 is a timing chart of the electromagnet driving device,
(A) shows the state of the switch from the on state to the off state on the way, (b) shows the state of the pulse signal, (c) shows the state of the current flowing through the coil, and (d) shows the state of the contact.
FIG. 20 is a circuit diagram showing a configuration of a conventional electromagnet driving device. FIGS. 21A and 21B are timing charts of the electromagnet driving device. FIG. 21A shows a state of a switch which is turned on from an on state to an off state, FIG. 21B shows a state of a pulse signal, FIG. 21C shows a state of a second transistor, and FIG. (d) shows the state of the current flowing through the coil, and (e) shows the state of the contact portion. FIG.
3 is a timing chart of the electromagnet driving device, wherein (a)
Indicates the state of the switch from the on state to the off state and further to the on state, (b) the state of the pulse signal, and (c)
Indicates the state of the second transistor, (d) indicates the state of the current flowing through the coil, and (e) and (f) indicate the states of the contact portions. FIG. 23 is a circuit diagram showing a configuration of another conventional electromagnet driving device related to FIG. FIGS. 24A and 24B are timing charts of the electromagnet drive device, wherein FIG. 24A shows a state of a switch, FIG. 24B shows a state of a current flowing through a coil, and FIG. 24C shows a state of a contact portion. FIG. 25 is a circuit diagram showing the configuration of another conventional electromagnet driving device related to FIG. FIGS. 26A and 26B are timing charts of the electromagnetic driving device. FIG. 26A shows the state of the switch, FIG. 26B shows the state of the current flowing through the coil, and FIG.
Indicates the state of the contact portion.

Conventionally, in an electric vehicle, industrial equipment, or the like, an electromagnet driving device that drives a plunger that contacts and separates a contact point by an electromagnet has been used in a relay for controlling on / off of power supply to a load.

FIG. 17 shows a first conventional example of this type of electromagnet driving device. This is provided on the relay for opening and closing the contact point U of the relay, and is provided with a field effect transistor A which is a switching element connected in series to the coil X of the electromagnet, and at a predetermined period. A regenerative current flows when the field effect transistor A, which includes a pulse signal generation circuit B for generating a pulse signal for driving the transistor A to turn on the transistor A and a diode C as a power absorbing element, is off. A regenerative circuit D connected in parallel to the coil X is provided. Specifically, a switch Z is provided between the power supply Y and the coil X.
Is connected.

Next, the operation of this device will be described. FIG.
As shown in (a), while the switch Z is in the ON state, the coil X is excited by applying a voltage from the power source Y and flowing a current. The power supply flowing through the coil X is as follows.
As shown in FIG. 18 (c), it is kept substantially constant by on / off control which is turned on when driven at a predetermined period by the pulse signal shown in FIG. When the transistor A is on, a current flows through the coil X, and the coil X is excited.
As shown in (d), the current flows from the power supply V to the load W when the contact portion U is turned on or is kept on. Then, when the transistor A is turned off, the back electromotive force generated in the coil X is
Is regenerated by flowing through the diode C. Therefore, even when the transistor A is in the off state, the coil X is excited, and as shown in FIG. 18D, the contact portion U is turned on or held in the on state. Electric current flows.

On the other hand, when the switch Z is opened and turned off as shown at a time T1 shown in FIG.
As shown in FIG. 19C, the current flowing through the coil X gradually decreases, and the attraction force of the electromagnet also gradually decreases. And
When the current becomes equal to or less than the predetermined value 11 as shown in FIG. 19C, the contact portion U is opened slightly later as shown at time T2 (for example, 10 ms after time T1) shown in FIG. 19D. The current stops flowing from the power supply V to the load W. Another conventional electromagnet driving device will be described with reference to FIGS. 23, 24 (a) and 24 (c). In FIG. 23, portions substantially corresponding to the components of the conventional example shown in FIG.
The same sign is attached. In the device of FIG. 23, when a voltage is supplied to the coil X, a direct current flows without regeneration.
When the power supply Y stops, a regenerative current flows through the regenerative diode C. As shown in FIGS. 24A and 24C, the time when the contact portion U is in the off state is the time T.
One to ten milliseconds later.

FIG. 20 shows a second conventional example of this type of electromagnet driving device. This is provided on the relay to open and close the contact portion U of the relay, and includes a field-effect type first transistor A connected in series to a coil X of an electromagnet, and a first transistor A at a predetermined period. A pulse signal generating circuit B for generating a pulse signal for driving the first transistor A to turn on the first transistor A, and a diode G in a parallel circuit of the second transistor E and the Zener diode F
Are connected in series and a regenerative circuit D connected in parallel to the coil X so that a regenerative current flows when the first transistor A is in an off state, and a third transistor C that controls on and off of the second transistor E. It is configured. Specifically, a switch Z is provided between the power supply Y and the coil X.

Next, the operation of this device will be described. While the switch Z is in the ON state, the coil X is excited by the application of a voltage from the power source Y and the flow of current, similarly to the first conventional example, and the current flowing through the coil X is different from that of the first conventional example. Similarly, it is kept constant by chopper control. While the first transistor A is in the off state, the current flowing through the coil X is regenerated by flowing through the regenerative circuit D using the back electromotive force generated in the coil X as a supply source. Therefore, while the switch Z is in the ON state, the coil X is excited, the contact portion U is in the ON state, and current flows from the power supply V to the load W.

When the switch Z is turned off, as at time T3 shown in FIG.
As shown in (b), the operation of the pulse signal generation circuit B stops, and the first transistor A is turned off. When the switch Z is turned off, the third transistor G is also turned off, so that the second transistor E is also turned off as shown in FIG. At this time, the energy stored in the coil X causes a current to flow through the Zener diode F and the diode C constituting the regenerative circuit D. This Zener diode F rapidly consumes the energy stored in the coil X when the switch Z is turned off, and the current flowing through the coil X based on the back electromotive force as shown in FIG. , Decrease rapidly. Accordingly, when the switch Z is turned off, the current flowing through the coil X is rapidly reduced, and the contact portion U is rapidly turned off as shown at time T4 in FIG. No current flows through W. The time from time T3 to time T4 (for example, 0.5 ms) is shorter than the time from time T1 to time T2 in the first conventional example. Therefore, the opening speed is improved. FIGS. 25 and 26 show another conventional electromagnetic drive device.
This will be described with reference to FIG. In FIG. 23, portions substantially corresponding to the components of the conventional example shown in FIG. 17 are denoted by the same reference numerals except for the pulse signal generation circuit. In the device of FIG. 25, when a voltage is supplied to the coil X, a DC voltage flows without regeneration. When the power supply Y stops, a regenerative current flows through the regenerative diode C and the Zener diode F. FIG. 26A and FIG.
As shown in (c), the time during which the contact portion U is in the off state is 0.5 ms from the time T1.

[0010]

In the above-described electromagnet driving apparatus of the first prior art, when the switch Z is turned off, the current flowing through the coil X is generated by using the back electromotive force generated in the coil X as a supply source. Is regenerated by flowing through the diode C, but does not decrease so rapidly. Since the current continues to flow through the coil X through the diode C for a while, the ON state of the electromagnet continues, and the relay contacts The part may not be quickly separated. That is, the current flowing through the coil X decreases gradually, and the attraction force of the electromagnet also decreases gradually, so that the contact opening speed of the relay is low and the breaking performance is low. When the opening speed is low as described above, even if a short circuit occurs in the circuit of the load W and the opening must be performed immediately, the opening is not performed for a while, so that a dangerous situation may occur. For example, specifically, when an electric vehicle causes a car accident or an accident occurs in industrial equipment, if a relay provided on a circuit of a motor as a power source is not immediately opened, a circuit is required. May be dangerous due to a short circuit.

In the above-described electromagnet driving apparatus of the second conventional example, when the switch Z is turned off, the Zener diode F rapidly consumes the energy stored in the coil X to reduce the reverse starting force. Since the current flowing through the coil X is rapidly reduced based on this, the electromagnet can be quickly turned off. That is, the current flowing through the coil X decreases rapidly and the attraction force of the electromagnet also decreases rapidly, so that the contact opening speed of the relay is improved and the breaking performance is improved.

However, in this switch, a contact switch or a semiconductor switch is used as the switch Z for controlling the application of the power supply voltage to on / off. In the case of the contact switch, the switch malfunctions instantaneously due to vibration or impact. In the case of a semiconductor switch, there is a possibility that an OFF malfunction may occur momentarily due to external noise, a malfunction of a signal for driving the switch, or the like. Specifically, when the electromagnet driving device is used in an electric vehicle or the like, the contact may be momentarily opened when the switch Z is a contact switch due to vibration generated in the vehicle body during traveling. Even when the switch Z is a semiconductor switch, the switch Z may be momentarily shut off due to external noise or the like due to a change in the external environment during traveling.

As described above, even when the switch Z is momentarily turned off unintentionally, the electromagnet is quickly turned off and malfunctions, and the relay contacts may malfunction. is there.

More specifically, as shown in FIGS. 22 (a) to 22 (c), at time T5, the switch Z is turned off unintentionally for some reason, and at a time T7 (for example, from time T5). Even if the switch Z is turned on again after 1 msec), the current flowing through the coil X rapidly decreases as shown in FIG. 22D, and as shown in FIG. At time T6 (for example, 0.5 ms after time T5) between time T7, contact portion U is opened.

When the current for maintaining the ON state of the contact U is set to be larger than the current value required for closing the contact U, as shown in FIG. When the current necessary for closing larger than the value 11 flows again, the contact portion U is turned on. On the other hand, when a current larger than the current holding the normal ON state is required to close the contact portion U, FIG.
The contact portion U does not close due to the flow of the current shown in (d), and the off state is continued after time T6 as shown in FIG.

The present invention has been made in view of the above points. The purpose of the present invention is to make it possible to quickly turn off the electromagnet when intended, and to assume that power supply is cut off instantaneously. Another object of the present invention is to provide an electromagnet driving device that does not accidentally turn off an electromagnet.

[0017]

According to a first aspect of the present invention, there is provided an electromagnet having a coil and a regenerative current when a voltage application to an electromagnet driving device is stopped. Flowing, a regenerative circuit that reduces the regenerative current when a predetermined time has elapsed after the application of the voltage to the electromagnet drive device has been stopped, and the predetermined time after the stop of the voltage application to the electromagnet drive device has elapsed. And a delay circuit that keeps the regenerative circuit on until the operation is completed.

According to a second aspect of the present invention, there is provided a switching device connected in series to the coil of the electromagnet;
A switch unit and a power absorbing element are formed in a parallel circuit in the regenerative circuit, and a diode is connected in series with the parallel circuit.The regenerative circuit includes a switch unit that is on, the switching member is on, and the electromagnet. When the switching unit is turned on and the switching member is turned off from a state where the power supply voltage is applied to the coil, the regenerative current flows through the coil, and power is supplied when the switching unit is turned off and the switching element is turned off. An electromagnet driving device comprising: a pulse signal generation circuit that generates a pulse signal for turning on the switching element at a predetermined period, wherein the absorption element rapidly reduces a regenerative current flowing through a coil of the electromagnet.

The invention according to claim 3 is characterized in that the switch section is connected in parallel to the power absorbing element, a phototransistor connected between a base and a collector of the transistor, and the phototransistor. And a light emitting diode that emits light so as to control on / off of the electromagnet.

According to a fourth aspect of the present invention, the delay circuit is charged during application of a voltage to the electromagnetic drive device, and is maintained until a predetermined time elapses after the voltage application to the electromagnetic drive device is stopped. An electromagnet drive device comprising: a capacitor capable of discharging toward the switch unit; and a Zener diode connected in parallel to the capacitor.

According to a fifth aspect of the present invention, the delay circuit is charged during the application of the voltage to the electromagnetic drive device, and is maintained until a predetermined time elapses after the voltage application to the electromagnetic drive device is stopped. A capacitor that can be discharged toward the switch unit, and a predetermined charging voltage is applied to the capacitor when the power supply voltage is higher than a predetermined voltage, and a voltage is applied to the capacitor when the power supply voltage is lower than the predetermined voltage. An electromagnet drive device comprising a power supply voltage detection circuit that stops.

According to a sixth aspect of the present invention, there is provided a reference voltage circuit for outputting a reference voltage, and a control signal for controlling the on / off of the switch section by comparing the reference voltage with the voltage across the capacitor. This is an electromagnet driving device including a comparator.

According to a seventh aspect of the present invention, there is provided a switching element connected in series to the coil of the electromagnet;
A pulse signal generating device that generates a pulse signal for turning on the switching element at a predetermined cycle, and the diode in which the coil of the electromagnet is connected in parallel to a series circuit of the power absorbing element and the diode. The regenerative current circuit includes a switch section and a power absorbing element forming a parallel circuit, and a diode connected in series to the parallel circuit.

The invention according to claim 8 is characterized in that a switching element connected in series to the coil of the electromagnet;
An electromagnet driving device including a pulse signal generation device that generates a pulse signal for turning on the switching element at a predetermined period, and a diode connected in parallel to a series circuit of the power absorption element and the coil. In the regenerative current circuit, a switch section and a power absorbing element form a parallel circuit, and a diode is connected in series to the parallel circuit.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of an electromagnet drive device according to the present invention is shown in FIGS. 1 to 3, a second embodiment is shown in FIG. 4, and a third embodiment is shown. From FIG. 5 to FIG.
A description will be given based on FIG.

FIG. 1 is a circuit diagram showing a configuration of an electromagnet driving device. FIGS. 2A and 2B are timing charts of the electromagnet driving device. FIG. 2A shows a state of a switch which is turned on from an on state to an off state, and FIG. , (C) shows the state of the second transistor, (d) shows the state of the current flowing through the coil, and (e) shows the state of the contact portion. 3A and 3B are timing charts of the electromagnet driving device. FIG. 3A shows a state of a switch which is turned on from an on state to an off state, and further becomes an on state. FIG. (C) shows the state of the second transistor, (d) shows the state of the current flowing through the coil, and (e) shows the state of the contact portion.

This is provided on the relay for opening and closing the contact portion U of the relay.

Reference numeral 1 denotes a first transistor (switching element), which is of a field effect type, and which has a power supply voltage Vin
Is connected in series to the coil 3 of the electromagnet to which
The on / off control of the supply of the current from the coil to the coil 3 can be controlled.

Reference numeral 4 denotes a regenerative circuit, in which a diode 7 is connected in series to a parallel circuit of a switch 24 and a first Zener diode 6 corresponding to a power absorbing element.

The switch unit 24 is connected to the photocoupler 8 and the second
And the transistor 5. The photocoupler 8 includes a light emitting diode 9 and the light emitting diode 9.
The phototransistor 10 is turned on and off by the emitted light.

More specifically, the diode 7 has its anode connected to the anode of the first Zener diode 6 and the emitter of the second transistor 5, respectively. This regenerative circuit 4 is connected to the coil 3 in parallel. The light emitting diode 9 has a delay circuit 11 whose anode is described later.
Is connected to one end of the discharge resistor 13 and the cathode is grounded. The phototransistor 10 has its emitter connected to the base of the second transistor 5 and its collector connected to the collector of the second transistor 5. The collector of the second transistor 5 is connected to the cathode of the first Zener diode 6.

Reference numeral 11 denotes a delay circuit, which comprises a charging resistor 12, a discharging resistor 13, a second Zener diode 14, and a capacitor 15. More specifically, the charging resistor 12 has one end connected to the coil 3 and the other end connected to the other end of the discharging resistor 13. The second Zener diode 14 is
The cathode is connected to the other end of the charging resistor 12 and the other end of the discharging resistor 13, respectively, and the anode is grounded. The capacitor 15 has one end grounded and the other end connected to the cathode of the second Zener diode 14. That is, the capacitor 15 is connected in parallel to the second Zener diode 14.

Reference numeral 16 denotes a pulse signal generating circuit which operates by applying a power supply voltage Vin of the power supply 2 and is connected to the gate of the first transistor 1. The pulse signal generating circuit 16 generates a pulse signal for driving the first transistor 1 at a predetermined period to turn on the first transistor 1 as shown in FIGS. 2B and 3B.

Reference numeral 17 denotes a switch, which is constituted by a contact switch or a semiconductor switch.
And the power supply voltage Vi of the power supply 2 to the pulse signal generation circuit 16
This is for turning on / off the application of n.

Next, the operation of this embodiment will be described. When the switch 17 is turned on, the power supply voltage Vin of the power supply 2
Are the coil 3, the delay circuit 11, and the pulse signal generation circuit 1.
6 respectively. Initially pulse signal generation circuit 1
6, the driving force is increased by increasing the duty ratio to increase the exciting current, and the contact U is turned on instantaneously. However, once the contact U is turned on, the exciting current for maintaining the ON state is small. Therefore, the pulse signal generation circuit 16 reduces the duty ratio to save energy. The initial coil exciting current is a predetermined current I1 (open current)
Always bigger than.

The capacitor 15 of the delay circuit 11 is charged through the charging resistor 12 until the voltage across the capacitor 15 becomes the Zener voltage of the second Zener diode 14. During the charging of the capacitor 15, when the voltage across the capacitor 15 becomes higher than the operating voltage of the light emitting diode 9, the light emitting diode 9 emits light, and the light emission turns the phototransistor 10 on. Is controlled so that the second transistor 5 is turned on.

Further, as shown in FIG.
When 7 is turned on, simultaneously with the above-described series of operations,
As shown in FIG. 2B, the pulse signal generation circuit 16 operates to generate a pulse signal for driving the first transistor 1 at a predetermined period to turn on the first transistor 1 (for example, the frequency is 20 kHz). This is due to the inductance and resistance of the coil.) Then, as the first transistor 1 is turned on and off, the current flowing through the coil 3 is chopper-controlled to maintain a substantially constant value. Specifically, while the first transistor 1 is in the ON state, a current is supplied from the power supply 2 to the coil 3, and the electromagnet is driven to be in the ON state. While the first transistor 1 is in the off state, the current flowing through the coil 3 using the reverse starting force generated in the coil 3 as a supply source is, as described above, the second transistor 5 in the on state. And a diode 7 are regenerated through a series circuit. By this series of operations, while the switch 17 is in the ON state, the coil 3 is excited, and FIG.
As shown in (e), the contact portion U is turned on, and a current flows from the power supply V to the load W.

Next, when the switch 17 is turned off as shown at time T8 in FIG. 2A, the operation of the pulse signal generating circuit 16 is stopped as shown in FIG.
The first transistor 1 is turned off. At the same time as this series of operations, the electric charge charged in the capacitor 15 becomes
Discharge is performed via the discharge resistor 13. Accordingly, the voltage between both ends of the capacitor 15 decreases from the Zener voltage of the second Zener diode 14 to 0, and the capacitor 1
While the voltage across the terminal 5 is higher than the operating voltage of the light emitting diode 9, the light emitting diode 9 emits light, so that the phototransistor 10 is turned on, and accordingly, the second transistor 5 remains on. (Figure 2
(C)). At this time, the energy stored in the coil 3 continues to flow through the series circuit of the second transistor 5 and the diode 7 connected in parallel to the coil 3 as shown in FIG. Therefore, as shown in FIG. 2E, the electromagnet keeps on.

Then, as at time T9 shown in FIG. 2C, a predetermined time T10 (for example, 1.5 milliseconds, which depends on the inductance and resistance of the coil) has elapsed since the switch 17 was turned off. And capacitor 15
Is smaller than the operating voltage of the light emitting diode 9, the light emitting diode 9 stops emitting light and the phototransistor 10 is turned off. Then, FIG.
As a result, the second transistor 5 is turned off accordingly, and the energy stored in the coil 8 is converted into a series circuit of the first Zener diode 6 and the diode 7 connected in parallel to the coil 8. It is consumed by flowing current to The first Zener diode 6 includes a coil 3
Rapidly consumes the energy stored in
As shown in (d), the current flowing through the coil 3 decreases rapidly, and the electromagnet is turned off. For example, as shown in FIG. 2E, the time when the electromagnet is in the off state is 2 ms from the time T8.

In this electromagnet driving device, even if the voltage application by the power supply 2 is stopped unintentionally, the delay circuit 11 supplies the current to the light emitting diode 9 until the predetermined time T10 elapses. Then, since the light emitting state of the light emitting diode 9 continues, the phototransistor 10 remains on, the second transistor 5 also turns on, a regenerative current can flow through the coil 3, and the coil 3 is excited. The electromagnet is continuously turned on. Further, after the lapse of the predetermined time T10, the current flowing through the coil 3 with the back electromotive force generated in the coil 3 as a supply source is regenerated by flowing through the second Zener diode 14 of the regenerative circuit 4 and rapidly regenerated. To decrease.

On the other hand, as shown in FIG.
At the time T11 before the time T10 (for example, 1 ms from the time T8) elapses.
When the switch 17 is turned on again in FIG.
As shown in (c), the ON state of the second transistor 5 is maintained. Therefore, as shown in FIG.
A regenerative current flows through the coil 3 until the supply of current from the power source 2 to the coil 3 is restarted, the coil 3 is excited, the ON state of the contact portion U is maintained, and a current flows from the power source V to the load W. Flows.

Accordingly, the electromagnet can be quickly turned off, and the electromagnet is not erroneously turned off depending on the momentary opening of the switch 17.

The voltage across the capacitor 15 to which the second Zener diode 14 is connected in parallel is equal to the power supply voltage V
Even if in varies, the Zener voltage is maintained, so that the amount of charge charged to the capacitor 15 becomes constant, and the amount of charge discharged to the light emitting diode 9 after the application is stopped becomes constant, so that the discharge time becomes constant. . Therefore, by appropriately setting the capacity of the capacitor 15, the predetermined time during which the light emitting diode 9 continues to emit light can be adjusted.

[Second Embodiment] FIG. 4 is a circuit diagram showing a configuration of an electromagnet driving device. In FIG. 4,
Components having substantially the same functions as those of the first embodiment are denoted by the same reference numerals, and only the differences from the first embodiment will be described.

In the present embodiment, in addition to the configuration of the first embodiment, the light emitting state of the light emitting diode 9 is compared by comparing a reference voltage circuit 18 for outputting a reference voltage with a voltage across the capacitor 15. And an internal power supply circuit 20 that outputs an internal power supply voltage Vf for driving the comparator 19 and operating the reference voltage circuit 18.

More specifically, the non-inverting input terminal of the comparator 19 is connected to the other end of the capacitor 15, the inverting input terminal is connected to the reference voltage circuit 18, and the output terminal is connected to the anode of the light emitting diode 9. . The comparator 19 compares the voltage between both ends of the capacitor 15 with the reference voltage. When the voltage between both ends of the capacitor 15 is higher than the reference voltage, the comparator 19 outputs a light emission control signal “high level” and outputs the light emission control signal “high level”. When the “high level” is applied to the light emitting diode 9 and the voltage across the capacitor 15 is lower than the reference voltage, the light emitting control signal “low level” is output, and the light emitting control signal “low level” is applied to the light emitting diode. Is done.

The discharge resistor 13 has one end grounded and the other end connected to the other end of the capacitor 15. That is, the discharging resistor 13 is connected in parallel to the capacitor 15.

Even when the switch 17 is turned off, the internal power supply circuit 20 maintains the output of the internal power supply voltage Vf for a while due to the charging energy stored during the on state. Therefore, even if the switch 17 is turned off, the operation of the comparator 19 and the reference voltage circuit 18 can be continued for a while.

Next, the operation of this embodiment will be described. When the switch 17 is turned on, the power supply voltage Vin of the power supply 2 is changed to the coil 3 and the delay circuit 1 as in the first embodiment.
1 and the pulse signal generation circuit 16 respectively.
The capacitor 15 of the delay circuit 11 is charged via the charging resistor 12. During the charging of the capacitor 15,
When the voltage between both ends of the capacitor 15 becomes higher than the reference voltage of the reference voltage circuit 18, the comparator 19 outputs the light emission control signal “high level”. Then, the light emitting diode 9 emits light, the phototransistor 10 is controlled to be turned on, and the second transistor 5 is controlled to be turned on.

When the switch 17 is turned on, the pulse signal generating circuit 16 operates to generate a pulse signal simultaneously with the above-described series of operations, as in the first embodiment. By controlling the transistor 1 to be turned on and off, the current flowing to the coil 3 is chopper-controlled to maintain a substantially constant value, and the electromagnet continues to be turned on.

Next, when the switch 17 is turned off,
The operation of the pulse signal generation circuit 16 stops, and the first transistor 1 is turned off. Simultaneously with this series of operations, the electric charge charged in the capacitor 15 is discharged via the discharging resistor 13. Accordingly, the voltage across the capacitor 15 decreases from the Zener voltage of the second Zener diode 14 to 0, and while the voltage across the capacitor 15 is higher than the reference voltage of the reference voltage circuit 18,
The comparator 19 outputs a generation control signal "high level" from the output terminal, and the light emission control signal "high level" is applied to the light emitting diode 9, and the light emitting diode 9 continues to emit light, so that the phototransistor 10 is turned on, Accordingly, the second transistor 5 remains on. At this time, the energy stored in the coil 3 continues to flow through the series circuit of the second transistor 5 and the diode 7 connected in parallel to the coil 3, so that the electromagnet keeps on. Becomes

When a predetermined time elapses after the switch 17 is turned off and the voltage across the capacitor 15 becomes smaller than the reference voltage of the reference voltage circuit 18, the comparator 19 outputs the light emission control signal "low level" from the output terminal. Then, the light emission control signal “low level” is applied to the light emitting diode 9 and the light emitting diode 9 stops emitting light, so that the phototransistor 10 is turned off, and accordingly, the second transistor 5 is also turned off. Therefore, the energy stored in the coil 3 is consumed by flowing a current to a series circuit of the first Zener diode 6 and the diode 7 connected in parallel to the coil 3. The first Zener diode 6 rapidly consumes the energy stored in the coil 3, the power flowing through the coil 3 decreases rapidly, and the electromagnet is turned off.

In this electromagnet driving device, as in the first embodiment, the electromagnet can be quickly turned off when intended, and malfunction does not occur.

As in the first embodiment, by setting the capacitance of the capacitor 15 appropriately, the predetermined time during which the light emitting diode 9 continues to emit light can be adjusted.

Further, the light emitting state of the light emitting diode 9 is controlled by a light emitting control signal output from the comparator 19 by comparing the reference voltage with the voltage across the capacitor 15, not by the voltage across the capacitor 15 which decreases with discharging. Is done. That is, even if the voltage between both ends of the capacitor 15 gradually decreases, the comparator 19 outputs the light emission control signal “high level” to cause the light emitting diode 9 to emit light while the voltage between both ends is larger than the reference voltage. When the voltage becomes lower than the reference voltage, a light emission control signal “low level” is output to stop the light emission of the light emitting diode 9. Therefore, since the light emitting state of the light emitting diode 9 can be controlled with the reference voltage as a boundary, the accuracy of the predetermined time during which the light emitting diode 9 continues to emit light can be increased.

[Third Embodiment] FIGS. 5 to 7 are circuit diagrams showing the configuration of an electromagnet driving device. In FIGS. 5 to 7, parts having substantially the same functions as those of the second embodiment are denoted by the same reference numerals, and only parts different from those of the second embodiment will be described.

In the second embodiment, the second Zener diode 14 is provided, whereas in the present embodiment, the power supply voltage detection circuit 21 is provided.

More specifically, the power supply voltage detection circuit 21 is driven using the internal power supply circuit 20 as a stable power supply, detects the state of voltage application by the power supply 2, and when the power supply voltage Vin is applied, the internal power supply circuit 20 And outputs a constant voltage charge control signal “high level” composed of the internal power supply voltage Vf output when the power supply voltage Vin is not applied.
The power supply voltage detection circuit 21 is provided with a pulse signal generation circuit 16.
And one end of the charging resistor 12.

Next, the operation of this embodiment will be described. When the switch 17 is turned on, the power supply voltage detection circuit 21 detects the voltage application state by the power supply 2 and outputs a constant voltage charge control signal “high level”. The voltage applied to both ends of the capacitor 15 is charged through the charging resistor 12 until the voltage across the capacitor 15 reaches the voltage of the charge control signal “high level”. During the charging of the capacitor 15, the comparator 19
Outputs a light emission control signal “high level” from an output terminal when the reference voltage of the reference voltage circuit 18 connected to the inverting input terminal is higher than the reference voltage, and the light emission control signal “high level” emits light. The light is applied to the diode 9, the light emitting diode 9 emits light, the phototransistor 10 is controlled to be turned on, and the second transistor 5 is controlled to be turned on.

When the switch 17 is in the ON state, the pulse signal generating circuit 16 operates to generate a pulse signal simultaneously with the above-described series of operations, as in the second embodiment. By controlling ON / OFF of 1, the current flowing through the coil 3 is chopper-controlled to maintain a substantially constant value, and the electromagnet continues to be turned on.

Next, when the switch 17 is turned off,
The power supply voltage detection circuit 21 detects the voltage application state by the power supply 2 and outputs a constant voltage charge control signal “low level”, the operation of the pulse signal generation circuit 16 stops, and the first transistor 1 It turns off. Simultaneously with this series of operations, the electric charge charged in the capacitor 15 is discharged via the discharging resistor 13. Capacitor 15
Decreases from the voltage of the charge control signal “high level” to 0, as in the second embodiment,
The electromagnet will remain on.

When a predetermined time elapses after the switch 17 is turned off and the voltage between both ends of the capacitor 15 becomes smaller than the reference voltage, the energy stored in the coil 3 as in the second embodiment. Are the first Zener diode 6 and the diode 7 connected in parallel to the coil 3.
The current flows through the series circuit and is consumed. The first Zener diode 6 rapidly consumes the energy stored in the coil 3, the current flowing through the coil 3 decreases rapidly, and the electromagnet is turned off.

In this electromagnet driving device, the electromagnet can be quickly turned off when it is intended, as in the first and second embodiments, and malfunction does not occur.

Further, similarly to the second embodiment, the light emitting state of the light emitting diode 9 can be controlled with the reference voltage as a boundary, so that the accuracy of the predetermined time during which the light emitting diode 9 continues to emit light can be improved. it can.

The charge state of the capacitor 15 is controlled not by the fluctuating power supply voltage Vin but by a constant voltage charge control signal output by the power supply voltage detection circuit 21 in accordance with the voltage application state by the power supply 2. Even if the power supply voltage Vin fluctuates, the amount of charge charged to the capacitor 15 becomes constant, and the amount of charge discharged toward the light emitting diode 9 after application is stopped becomes constant, so that the discharge time becomes constant. Therefore, by appropriately setting the capacity of the capacitor 15, the predetermined time during which the light emitting diode 9 continues to emit light can be adjusted.

In each of the first to third embodiments, the delay circuit 11 is charged during the application of the voltage by the power supply 2 and goes to the light emitting diode 9 until a predetermined time elapses after the application of the voltage is stopped. And dischargeable capacitor 15
However, the present invention is not limited to such a configuration, and a power supply separate from the power supply 2 and a timer circuit may be used as shown in FIG.

In each of the first and second embodiments, the second Zener diode 14 is connected in parallel to the capacitor 15 in the delay circuit 11. When it is not necessary to make the adjustment of strictly, the second Zener diode 14 may not be connected in parallel, and in that case, the number of parts can be reduced.

Also, as shown in FIG.
Alternatively, the phototransistor 10 may be used as the second transistor 5 in the first to third embodiments. This configuration can omit the second transistor 5 in the first to third embodiments when the current supplied to the coil 3 is relatively small,
The number of parts can be reduced.

Further, as shown in FIG.
May use the photodiode 22 without using the phototransistor 10 in the first to third embodiments. In this case, the photodiode 22 generates a voltage by the light emission of the light emitting diode 9, and turns on the field effect transistor 23.

FIGS. 8 to 11 show modifications of the first embodiment based on the circuit diagram shown in FIG. In FIG. 8, the connection position of the switch section of the regenerative circuit is changed. In FIG. 9, the position of the switching element is set to the plus side of the power supply 2. In FIG. 10, the connection position of the switch section of the regenerative circuit is changed, and the position of the switching element is set to the plus side of the power supply 2. These circuits are also shown in FIGS.
3 (e) and the timing charts shown in FIGS. 3 (a) to 3 (e). In particular, FIG. 8 is a circuit diagram showing a case where a photocoupler 8, which is not always present, is used. A more detailed circuit diagram related to FIG. 10 is shown in FIG. In these examples, when a regenerative current flows, the regenerative circuits in the circuit diagram have the same structure.

The operation of the device shown in FIG. 11 will be described below. When the power supply voltage is applied, the base current of the transistor 5 is supplied from the power supply via the resistor 13 to turn on the transistor, and the switching of the coil current is controlled. When the application of the power supply voltage is stopped, the charge stored in the capacitor 15 is supplied as the base current of the transistor 5. Thus, the transistor 5 is turned on within a predetermined time,
Attenuation of the coil current can be suppressed.

After a lapse of a predetermined time from the stop of the application of the power supply voltage, the electric charge stored in the capacitor 15 decreases, and the base current that can keep the transistor on cannot be supplied. Is turned off, and the coil current flows through the Zener diode and rapidly attenuates.

The transistor 5 can be a field effect transistor (FET). When using an FET,
Electric charges are stored in the transistor 15, and a voltage can be applied to the gate of the FET within a predetermined time after the application of the power supply voltage is stopped, so that the FET can be turned on. After a lapse of a predetermined time, the electric charge stored in the capacitor 15 is discharged, and the voltage applied to the gate also decreases.
ET turns off. Since the photocoupler 8 is generally expensive, an FET is used to reduce the production cost.

The concept of the modified example is also applied in the second and third embodiments of the present invention. Another embodiment described below also achieves the object of the present invention. 13 and 14 showing another embodiment of the present invention, a configuration having characteristics substantially corresponding to those of the components of the first embodiment of the present invention shown in FIG. Elements include a pulse signal generation circuit 16 and a switch section 24.
The same reference numerals are given except for the omission of the photocoupler 8 from FIG.

The operation of the device shown in FIGS. 13 and 14 is the same. When the application of the voltage from the power supply 2 is stopped, the regenerative current flows through the switch unit 24 and the regenerative diode, and suppresses the attenuation of the coil current. Thereafter, when a predetermined time has elapsed, the switch 2 is turned off, a regenerative current flows through the Zener diode, and the coil current rapidly attenuates.

FIGS. 15A to 15C show the switch 1
7 shows a timing chart of the electromagnet drive device when turning off the switch 7; Similar to the first embodiment of the present invention, time T10 'is 1.5 ms after time T8'.

FIGS. 16 (a) to 16 (c) show timing charts of the electromagnet drive device when the application of voltage from the power supply is interrupted unexpectedly and instantaneously. Similar to the first embodiment of the present invention, the time T11 '
One millisecond after 8 '. Generally, the photocoupler 8 is expensive, so that the production cost is reduced.
Is omitted.

In these embodiments, the switching frequency and the delay time are 20 kHz and 1.
5 ms. However, the invention is not limited to these values. These values change depending on the inductance and resistance of the electromagnetic coil. When the resistance of the electromagnetic coil is smaller than the inductance, the energy consumed by the resistance of the coil becomes smaller, and when the inductance of the coil is larger, the energy stored in the coil becomes larger. Thus, the amount of temporal attenuation of the regenerative current when the switching element is off (regeneration mode) is reduced. That is, the time required for the coil current to reach the current for opening the electromagnet from the time when the switching is turned off becomes long, so that the switching frequency is small and the delay time can be set long.

If heat generation of the electromagnet coil is not a problem, increasing the average current of the coil holding the electromagnet increases the time for the coil current to reach the current that the electromagnet opens from the time when the switching is turned off. Therefore, the switching frequency can be set low and the delay time can be set long.

[0080]

According to the first, second, seventh, and eighth aspects of the present invention, the delay circuit is provided with a switch unit until a predetermined time elapses even if the application of the power supply voltage is stopped instantaneously. Is kept on, the coil current is regenerated through the switch unit using the back electromotive force of the coil as a supply source, so that the coil is continuously excited and the electromagnet can be kept on. further,
After a lapse of a predetermined time, the current flowing through the coil using the back electromotive force generated in the coil as a supply source is regenerated by flowing through the power absorbing element of the regenerative circuit, and rapidly decreases. Therefore, when intended, the driving of the electromagnet can be quickly stopped, and the coil current can be rapidly attenuated. In the relay, the contact opening speed can be improved and the breaking performance can be improved. Moreover,
In an unintended momentary stop of the power supply voltage, the electromagnet does not malfunction open.

According to a third aspect of the present invention, in addition to the effect of the second aspect of the present invention, the switch section is provided between the transistor provided in parallel with the power absorbing element and a base and a collector of the transistor. And a light emitting diode that emits light so as to control the on / off of the phototransistor, so that the regenerative current can be used as a base current for driving the transistor when the application of the power supply voltage is stopped. Therefore, operation can be performed without requiring a separate power supply for driving the transistors.

According to a fourth aspect of the present invention, in addition to the effect of the second aspect, the capacitor connected in parallel with the Zener diode is maintained at the Zener voltage even when the power supply voltage fluctuates. Since the amount of electric charge charged to the capacitor becomes constant and the current flowing toward the light emitting diode becomes constant after the application is stopped, the discharge time becomes constant. Therefore, by appropriately setting the capacitance of the capacitor, the predetermined time during which the light emitting diode continues to emit light can be adjusted.

According to a fifth aspect of the present invention, in addition to the effect of the second aspect of the present invention, the capacitor outputs not the fluctuating power supply voltage but the power supply voltage detection circuit according to the applied state of the power supply voltage. Since the charge state is controlled by the constant voltage charge control signal, even if the power supply voltage fluctuates, the amount of charge charged to the capacitor becomes constant, and the current flowing toward the light emitting diode after the application is stopped becomes constant. Therefore, the discharge time becomes constant. Therefore, by appropriately setting the capacitance of the capacitor, the predetermined time during which the light emitting diode continues to emit light can be adjusted.

According to a sixth aspect of the present invention, in addition to the effect of the fourth aspect of the present invention, the light emitting diode is not a voltage across the capacitor that decreases as the light emitting diode is discharged. The light emission state is controlled by the light emission control signal output by comparing the above. Therefore, even if the voltage across the capacitor gradually decreases, the light emission state can be instantaneously controlled by the light emission control signal, so that the accuracy of the predetermined time during which the light emitting diode continues to emit light can be improved.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a configuration of a first embodiment of an electromagnet driving device.

FIG. 2 is a timing chart of the electromagnet driving device;
(A) is the state of the switch from the on state to the off state on the way, (b) is the state of the pulse signal, (c) is the state of the second transistor, (d) is the state of the current flowing through the coil,
(E) shows the state of the contact portion.

FIG. 3 is a timing chart of the electromagnet driving device;
(A) is the state of the switch from the on state to the off state and further to the on state on the way, (b) is the state of the pulse signal,
(C) shows the state of the second transistor, (d) shows the state of the current flowing through the coil, and (e) shows the state of the contact portion.

FIG. 4 is a circuit diagram showing a configuration of a second embodiment of the electromagnet driving device.

FIG. 5 is a circuit diagram illustrating a configuration of an electromagnet driving device according to a third embodiment.

FIG. 6 is a circuit diagram showing a configuration of another embodiment of the electromagnet driving device.

FIG. 7 is a circuit diagram showing a configuration of another embodiment of the electromagnet driving device.

FIG. 8 is a circuit diagram illustrating an embodiment.

FIG. 9 is a circuit diagram illustrating an embodiment.

FIG. 10 is a circuit diagram illustrating an embodiment;

FIG. 11 is a circuit diagram illustrating an embodiment;

FIG. 12 is a circuit diagram including a timer circuit.

FIG. 13 is a circuit diagram showing another embodiment.

FIG. 14 is a circuit diagram showing another embodiment.

FIG. 15 is a diagram showing a timing chart of another embodiment.

FIG. 16 is a diagram showing a timing chart of another embodiment.

FIG. 17 is a circuit diagram showing a configuration of a conventional electromagnet driving device.

FIGS. 18A and 18B are timing charts of the electromagnet driving device, wherein FIG. 18A shows a state of a switch in an ON state, FIG. 18B shows a state of a pulse signal, FIG.
(D) shows the state of the contact portion.

FIGS. 19A and 19B are timing charts of the electromagnet driving device, wherein FIG. 19A shows a state of a switch which is turned on from an on state to an off state, FIG. 19B shows a state of a pulse signal, FIG. (D) shows the state of the contact portion.

FIG. 20 is a circuit diagram showing the configuration of a conventional electromagnet driving device.

FIGS. 21A and 21B are timing charts of the electromagnet driving device, wherein FIG. 21A shows a state of a switch which is turned on from an on state to an off state, FIG. 21B shows a state of a pulse signal, FIG. (D) shows the state of the current flowing through the coil, and (e) shows the state of the contact portion.

FIGS. 22A and 22B are timing charts of the electromagnet driving device, wherein FIG. 22A shows the state of the switch from the on state to the off state in the middle and further turns on, FIG. 22B shows the state of the pulse signal, and FIG. (D) shows the state of the current flowing through the coil, and (e) and (f) show the state of the contact.

FIG. 23 is a circuit diagram showing another electromagnet driving device.

FIG. 24 is a diagram showing a timing chart of another electromagnet driving device.

FIG. 25 is a circuit diagram showing another electromagnet driving device.

FIG. 26 is a diagram showing a timing chart of another electromagnet driving device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Switching element 2 Power supply 3 Coil 4 Regenerative circuit 5 2nd transistor 6 Power absorption element 7 Diode 9 Light emitting diode 10 Phototransistor 11 Delay circuit 14 2nd Zener diode 15 Capacitor 16 Pulse signal generation circuit 18 Reference voltage circuit 19 Comparator 21 Power supply voltage detection circuit 22 Photodiode 24 Switch section

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[Procedure amendment]

[Submission date] February 6, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

[Title of the Invention] Electromagnet drive

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnet driving device for driving a relay for controlling on / off of power supply to a load in an electric vehicle or the like.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to FIGS. FIG. 17 is a circuit diagram showing a configuration of a conventional electromagnet driving device. FIGS. 18A and 18B are timing charts of the electromagnet driving device. FIG. 18A shows the state of the switch in the ON state, FIG. 18B shows the state of the pulse signal, FIG. 18C shows the state of the current flowing through the coil, and FIG. The state is shown. FIG. 19 is a timing chart of the electromagnet driving device,
(A) shows the state of the switch from the on state to the off state on the way, (b) shows the state of the pulse signal, (c) shows the state of the current flowing through the coil, and (d) shows the state of the contact.
FIG. 20 is a circuit diagram showing a configuration of a conventional electromagnet driving device. FIGS. 21A and 21B are timing charts of the electromagnet driving device. FIG. 21A shows a state of a switch which is turned on from an on state to an off state, FIG. 21B shows a state of a pulse signal, FIG. 21C shows a state of a second transistor, and FIG. (d) shows the state of the current flowing through the coil, and (e) shows the state of the contact portion. FIG.
3 is a timing chart of the electromagnet driving device, wherein (a)
Indicates the state of the switch from the on state to the off state and further to the on state, (b) the state of the pulse signal, and (c)
Indicates the state of the second transistor, (d) indicates the state of the current flowing through the coil, and (e) and (f) indicate the states of the contact portions. FIG. 23 is a circuit diagram showing a configuration of another conventional electromagnet driving device related to FIG. FIGS. 24A and 24B are timing charts of the electromagnet drive device, wherein FIG. 24A shows a state of a switch, FIG. 24B shows a state of a current flowing through a coil, and FIG. 24C shows a state of a contact portion. FIG.
FIG. 21 is a circuit diagram showing a configuration of another conventional electromagnet driving device related to FIG. FIGS. 26A and 26B are timing charts of the electromagnetic driving device. FIG. 26A shows the state of the switch, FIG. 26B shows the state of the current flowing through the coil, and FIG.
Indicates the state of the contact portion.

Conventionally, in an electric vehicle, industrial equipment, or the like, an electromagnet driving device that drives a plunger that contacts and separates a contact point by an electromagnet has been used in a relay for controlling on / off of power supply to a load.

FIG. 17 shows a first conventional example of this type of electromagnet driving device. This is provided on the relay for opening and closing the contact point U of the relay, and is provided with a field effect transistor A which is a switching element connected in series to the coil X of the electromagnet, and at a predetermined period. A regenerative current flows when the field effect transistor A, which includes a pulse signal generation circuit B for generating a pulse signal for driving the transistor A to turn on the transistor A and a diode C as a power absorbing element, is off. A regenerative circuit D connected in parallel to the coil X is provided. Specifically, a switch Z is provided between the power supply Y and the coil X.
Is connected.

Next, the operation of this device will be described. FIG.
As shown in (a), while the switch Z is in the ON state, the coil X is excited by applying a voltage from the power source Y and flowing a current. The current flowing through the coil X is determined by the transistor A from the pulse signal generation circuit B as shown in FIG.
As shown in FIG. 18 (c), it is kept substantially constant by on / off control which is turned on when driven at a predetermined period by the pulse signal shown in FIG. When the transistor A is on, a current flows through the coil X, and the coil X is excited.
As shown in (d), the current flows from the power supply V to the load W when the contact portion U is turned on or is kept on. Then, when the transistor A is turned off, the back electromotive force generated in the coil X is
Is regenerated by flowing through the diode C. Therefore, even when the transistor A is in the off state, the coil X is excited, and as shown in FIG. 18D, the contact portion U is turned on or held in the on state. Electric current flows.

On the other hand, when the switch Z is opened and turned off as shown at a time T1 shown in FIG.
As shown in FIG. 19C, the current flowing through the coil X gradually decreases, and the attraction force of the electromagnet also gradually decreases. And
When the current becomes equal to or less than the predetermined value I1 as shown in FIG. 19C, the contact point U is slightly delayed as shown at a time T2 (for example, 10 ms after the time T1) shown in FIG. 19D. The contact is opened, and no current flows from the power supply V to the load W. Another conventional electromagnet driving device will be described with reference to FIGS. 23, 24 (a) and 24 (c). In FIG. 23, portions substantially corresponding to the components of the conventional example shown in FIG.
The same sign is attached. In the device of FIG. 23, when a voltage is supplied to the coil X, a direct current flows without regeneration.
When the power supply Y stops, a regenerative current flows through the regenerative diode C. As shown in FIGS. 24A and 24C, the time when the contact portion U is in the off state is the time T.
One to ten milliseconds later.

FIG. 20 shows a second conventional example of this type of electromagnet driving device. This is provided on the relay to open and close the contact portion U of the relay, and includes a field-effect type first transistor A connected in series to a coil X of an electromagnet, and a first transistor A at a predetermined period. A pulse signal generation circuit B for generating a pulse signal for driving the first transistor A to turn on the first transistor A, and a diode C in a parallel circuit of the second transistor E and the Zener diode F
Are connected in series, a regenerative circuit D connected in parallel to the coil X so that a regenerative current flows when the first transistor A is in an off state, and a third transistor G for controlling the on / off of the second transistor E. It is configured. Specifically, a switch Z is provided between the power supply Y and the coil X.

Next, the operation of this device will be described. While the switch Z is in the ON state, the coil X is excited by the application of a voltage from the power source Y and the flow of current, similarly to the first conventional example, and the current flowing through the coil X is different from that of the first conventional example. Similarly, it is kept constant by chopper control. While the first transistor A is in the off state, the current flowing through the coil X is regenerated by flowing through the regenerative circuit D using the back electromotive force generated in the coil X as a supply source. Therefore, while the switch Z is in the ON state, the coil X is excited, the contact portion U is in the ON state, and current flows from the power supply V to the load W.

When the switch Z is turned off, as at time T3 shown in FIG.
As shown in (b), the operation of the pulse signal generation circuit B stops, and the first transistor A is turned off. When the switch Z is turned off, the third transistor G is also turned off, so that the second transistor E is also turned off as shown in FIG. At this time, the energy stored in the coil X causes a current to flow through the Zener diode F and the diode C constituting the regenerative circuit D. This Zener diode F rapidly consumes the energy stored in the coil X when the switch Z is turned off, and the current flowing through the coil X based on the back electromotive force as shown in FIG. , Decrease rapidly. Accordingly, when the switch Z is turned off, the current flowing through the coil X is rapidly reduced, and the contact portion U is rapidly turned off as shown at time T4 in FIG. No current flows through W. The time from time T3 to time T4 (for example, 0.5 ms) is shorter than the time from time T1 to time T2 in the first conventional example. Therefore, the opening speed is improved. FIGS. 25 and 26 show another conventional electromagnetic drive device.
This will be described with reference to FIG. The figure
In FIG. 25 , portions substantially corresponding to the components of the conventional example shown in FIG. 17 are denoted by the same reference numerals except for the pulse signal generation circuit. In the device of FIG. 25, when a voltage is supplied to the coil X, a direct current flows without regeneration. When the power supply Y stops, a regenerative current flows through the regenerative diode C and the Zener diode F. FIG. 26A and FIG.
As shown in (c), the time during which the contact portion U is in the off state is 0.5 ms from the time T1.

[0010]

In the above-described electromagnet driving apparatus of the first prior art, when the switch Z is turned off, the current flowing through the coil X is generated by using the back electromotive force generated in the coil X as a supply source. Is regenerated by flowing through the diode C, but does not decrease so rapidly. Since the current continues to flow through the coil X through the diode C for a while, the ON state of the electromagnet continues, and the relay contacts The part may not be quickly separated. That is, the current flowing through the coil X decreases gradually, and the attraction force of the electromagnet also decreases gradually, so that the contact opening speed of the relay is low and the breaking performance is low. When the opening speed is low as described above, even if a short circuit occurs in the circuit of the load W and the opening must be performed immediately, the opening is not performed for a while, so that a dangerous situation may occur. For example, specifically, when an electric vehicle causes a car accident or an accident occurs in industrial equipment, if a relay provided on a circuit of a motor as a power source is not immediately opened, a circuit is required. May be dangerous due to a short circuit.

In the above-described electromagnet driving apparatus of the second conventional example, when the switch Z is turned off, the Zener diode F rapidly consumes the energy stored in the coil X to generate a back electromotive force . Since the current flowing through the coil X is rapidly reduced based on this, the electromagnet can be quickly turned off. That is, the current flowing through the coil X decreases rapidly and the attraction force of the electromagnet also decreases rapidly, so that the contact opening speed of the relay is improved and the breaking performance is improved.

However, in this switch, a contact switch or a semiconductor switch is used as the switch Z for controlling the application of the power supply voltage to on / off. In the case of the contact switch, the switch malfunctions instantaneously due to vibration or impact. In the case of a semiconductor switch, there is a possibility that an OFF malfunction may occur momentarily due to external noise, a malfunction of a signal for driving the switch, or the like. Specifically, when the electromagnet driving device is used in an electric vehicle or the like, the contact may be momentarily opened when the switch Z is a contact switch due to vibration generated in the vehicle body during traveling. Even when the switch Z is a semiconductor switch, the switch Z may be momentarily shut off due to external noise or the like due to a change in the external environment during traveling.

As described above, even when the switch Z is momentarily turned off unintentionally, the electromagnet is quickly turned off and malfunctions, and the relay contacts may malfunction. is there.

More specifically, as shown in FIGS. 22 (a) to 22 (c), at time T5, the switch Z is turned off unintentionally for some reason, and at a time T7 (for example, from time T5). Even if the switch Z is turned on again after 1 msec), the current flowing through the coil X rapidly decreases as shown in FIG. 22D, and as shown in FIG. At time T6 (for example, 0.5 ms after time T5) between time T7, contact portion U is opened.

When the current for maintaining the ON state of the contact U is set to be larger than the current value required for closing the contact U, as shown in FIG. When the current required for closing larger than the value I1 flows again, the contact portion U is turned on. On the other hand, when a current larger than the current holding the normal ON state is required to close the contact portion U, FIG.
The contact portion U does not close due to the flow of the current shown in (d), and the off state is continued after time T6 as shown in FIG.

The present invention has been made in view of the above points. The purpose of the present invention is to make it possible to quickly turn off the electromagnet when intended, and to assume that power supply is cut off instantaneously. Another object of the present invention is to provide an electromagnet driving device that does not accidentally turn off an electromagnet.

[0017]

According to a first aspect of the present invention, there is provided an electromagnet having a coil and a regenerative current when a voltage application to an electromagnet driving device is stopped. Flowing, a regenerative circuit that reduces the regenerative current when a predetermined time has elapsed after the application of the voltage to the electromagnet drive device has been stopped, and the predetermined time after the stop of the voltage application to the electromagnet drive device has elapsed. And a delay circuit that keeps the regenerative circuit on until the operation is completed.

According to a second aspect of the present invention, there is provided a switching device connected in series to the coil of the electromagnet ;
Is formed by a parallel circuit of a switch portion and a power absorbing element, a diode is connected in series to the parallel circuit, before Symbol switch unit is the said switch portion and the switching element from the on state is on ON If the switching element is turned off, the regenerative current flows to the coil, before the switching element the switch unit is off is the power absorbing element in the case of off flowing in the coil of the electromagnet
It said regeneration circuit for reducing the serial regenerative current rapidly, an electromagnet driving apparatus comprising a pulse signal generating circuit for generating a pulse signal for the switching element to the on state at a predetermined cycle.

The invention according to claim 3 is characterized in that the switch section is connected in parallel to the power absorbing element, a phototransistor connected between a base and a collector of the transistor, and the phototransistor. And a light emitting diode that emits light so as to control on / off of the electromagnet.

According to a fourth aspect of the present invention, the delay circuit is charged during application of a voltage to the electromagnetic drive device, and is maintained until a predetermined time elapses after the voltage application to the electromagnetic drive device is stopped. An electromagnet drive device comprising: a capacitor capable of discharging toward the switch unit; and a Zener diode connected in parallel to the capacitor.

According to a fifth aspect of the present invention, the delay circuit is charged during the application of the voltage to the electromagnetic drive device, and is maintained until a predetermined time elapses after the voltage application to the electromagnetic drive device is stopped. A capacitor that can be discharged toward the switch unit, and a predetermined charging voltage is applied to the capacitor when the power supply voltage is higher than a predetermined voltage, and a voltage is applied to the capacitor when the power supply voltage is lower than the predetermined voltage. An electromagnet drive device comprising a power supply voltage detection circuit that stops.

According to a sixth aspect of the present invention, there is provided a reference voltage circuit for outputting a reference voltage, and a control signal for controlling the on / off of the switch section by comparing the reference voltage with the voltage across the capacitor. This is an electromagnet driving device including a comparator.

According to a seventh aspect of the present invention, there is provided a switching element connected in series to the coil of the electromagnet;
And the pulse signal generator for generating a pulse signal for the switching element to the on state in a predetermined cycle, the electrodeposition
Forming a series circuit with the force absorbing element, wherein the series circuit and the
An electromagnet driving device comprising: a diode in which the coil of a magnet is connected in parallel ; wherein the regenerative circuit includes a switch unit and a power absorption element forming a parallel circuit, and the diode includes a parallel circuit. Are connected in series.

The invention according to claim 8 is characterized in that a switching element connected in series to the coil of the electromagnet;
An electromagnet driving device including a pulse signal generation device that generates a pulse signal for turning on the switching element at a predetermined period, and a diode connected in parallel to a series circuit of the power absorption element and the coil. Yes, said
In the regenerative circuit, the switch section and the power absorbing element form a parallel circuit, and a diode is connected in series to the parallel circuit.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of an electromagnet drive device according to the present invention is shown in FIGS. 1 to 3, a second embodiment is shown in FIG. 4, and a third embodiment is shown. From FIG. 5 to FIG.
A description will be given based on FIG.

FIG. 1 is a circuit diagram showing a configuration of an electromagnet driving device. FIGS. 2A and 2B are timing charts of the electromagnet driving device. FIG. 2A shows a state of a switch which is turned on from an on state to an off state, and FIG. , (C) shows the state of the second transistor, (d) shows the state of the current flowing through the coil, and (e) shows the state of the contact portion. 3A and 3B are timing charts of the electromagnet driving device. FIG. 3A shows a state of a switch which is turned on from an on state to an off state, and further becomes an on state. FIG. (C) shows the state of the second transistor, (d) shows the state of the current flowing through the coil, and (e) shows the state of the contact portion.

This is provided on the relay for opening and closing the contact portion U of the relay.

Reference numeral 1 denotes a first transistor (switching element), which is of a field effect type, and which has a power supply voltage Vin
Is connected in series to the coil 3 of the electromagnet to which
The on / off control of the supply of the current from the coil to the coil 3 can be controlled.

Reference numeral 4 denotes a regenerative circuit, in which a diode 7 is connected in series to a parallel circuit of a switch 24 and a first Zener diode 6 corresponding to a power absorbing element.

The switch unit 24 is connected to the photocoupler 8 and the second
And the transistor 5. The photocoupler 8 includes a light emitting diode 9 and the light emitting diode 9.
The phototransistor 10 is turned on and off by the emitted light.

More specifically, the diode 7 has its anode connected to the anode of the first Zener diode 6 and the emitter of the second transistor 5, respectively. This regenerative circuit 4 is connected to the coil 3 in parallel. The light emitting diode 9 has a delay circuit 11 whose anode is described later.
Is connected to one end of the discharge resistor 13 and the cathode is grounded. The phototransistor 10 has its emitter connected to the base of the second transistor 5 and its collector connected to the collector of the second transistor 5. The collector of the second transistor 5 is connected to the cathode of the first Zener diode 6.

Reference numeral 11 denotes a delay circuit, which comprises a charging resistor 12, a discharging resistor 13, a second Zener diode 14, and a capacitor 15. More specifically, the charging resistor 12 has one end connected to the coil 3 and the other end connected to the other end of the discharging resistor 13. The second Zener diode 14 is
The cathode is connected to the other end of the charging resistor 12 and the other end of the discharging resistor 13, respectively, and the anode is grounded. The capacitor 15 has one end grounded and the other end connected to the cathode of the second Zener diode 14. That is, the capacitor 15 is connected in parallel to the second Zener diode 14.

Reference numeral 16 denotes a pulse signal generating circuit which operates by applying a power supply voltage Vin of the power supply 2 and is connected to the gate of the first transistor 1. The pulse signal generating circuit 16 generates a pulse signal for driving the first transistor 1 at a predetermined period to turn on the first transistor 1 as shown in FIGS. 2B and 3B.

Reference numeral 17 denotes a switch, which is constituted by a contact switch or a semiconductor switch.
And the power supply voltage Vi of the power supply 2 to the pulse signal generation circuit 16
This is for turning on / off the application of n.

Next, the operation of this embodiment will be described. When the switch 17 is turned on, the power supply voltage Vin of the power supply 2
Are the coil 3, the delay circuit 11, and the pulse signal generation circuit 1.
6 respectively. Initially pulse signal generation circuit 1
6, the driving force is increased by increasing the duty ratio to increase the exciting current, and the contact U is turned on instantaneously. However, once the contact U is turned on, the exciting current for maintaining the ON state is small. Therefore, the pulse signal generation circuit 16 reduces the duty ratio to save energy. The initial coil exciting current is a predetermined current I1 (open current)
Always bigger than.

The capacitor 15 of the delay circuit 11 is charged through the charging resistor 12 until the voltage across the capacitor 15 becomes the Zener voltage of the second Zener diode 14. During the charging of the capacitor 15, when the voltage across the capacitor 15 becomes higher than the operating voltage of the light emitting diode 9, the light emitting diode 9 emits light, and the light emission turns the phototransistor 10 on. Is controlled so that the second transistor 5 is turned on.

Further, as shown in FIG.
When 7 is turned on, simultaneously with the above-described series of operations,
As shown in FIG. 2B, the pulse signal generation circuit 16 operates to generate a pulse signal for driving the first transistor 1 at a predetermined period to turn on the first transistor 1 (for example, the frequency is 20 kHz). This is due to the inductance and resistance of the coil.) Then, as the first transistor 1 is turned on and off, the current flowing through the coil 3 is chopper-controlled to maintain a substantially constant value. Specifically, while the first transistor 1 is in the ON state, a current is supplied from the power supply 2 to the coil 3, and the electromagnet is driven to be in the ON state. While the first transistor 1 is in the off state, the current flowing through the coil 3 using the reverse starting force generated in the coil 3 as a supply source is, as described above, the second transistor 5 in the on state. And a diode 7 are regenerated through a series circuit. By this series of operations, while the switch 17 is in the ON state, the coil 3 is excited, and FIG.
As shown in (e), the contact portion U is turned on, and a current flows from the power supply V to the load W.

Next, when the switch 17 is turned off at time T8 as shown in FIG. 2 (a) , the operation of the pulse signal generating circuit 16 is stopped as shown in FIG. 2 (b). And the first
Transistor 1 is turned off. Simultaneously with this series of operations, the electric charge charged in the capacitor 15 is discharged via the discharging resistor 13. Therefore, the capacitor 15
Is reduced from the Zener voltage of the second Zener diode 14 to 0, and while the voltage across the capacitor 15 is higher than the operating voltage of the light emitting diode 9, the light emitting diode 9 emits light. From this, the phototransistor 10 is turned on, and the second transistor 5 is kept on accordingly (FIG. 2).
(C)). At this time, the energy stored in the coil 3 continues to flow through the series circuit of the second transistor 5 and the diode 7 connected in parallel to the coil 3 as shown in FIG. Therefore, as shown in FIG. 2E, the electromagnet keeps on.

Then, as at time T9 shown in FIG. 2C, a predetermined time T10 (for example, 1.5 milliseconds, which depends on the inductance and resistance of the coil) has elapsed since the switch 17 was turned off. And capacitor 15
Is smaller than the operating voltage of the light emitting diode 9, the light emitting diode 9 stops emitting light and the phototransistor 10 is turned off. Then, FIG.
As a result, the second transistor 5 is turned off accordingly, and the energy stored in the coil 8 is converted into a series circuit of the first Zener diode 6 and the diode 7 connected in parallel to the coil 8. It is consumed by flowing current to The first Zener diode 6 includes a coil 3
Rapidly consumes the energy stored in
As shown in (d), the current flowing through the coil 3 decreases rapidly, and the electromagnet is turned off. For example, as shown in FIG. 2E, the time during which the electromagnet is in the ON state is 2 ms from time T8.

In this electromagnet driving device, even if the voltage application by the power supply 2 is stopped unintentionally, the delay circuit 11 supplies the current to the light emitting diode 9 until the predetermined time T10 elapses. Then, since the light emitting state of the light emitting diode 9 continues, the phototransistor 10 remains on, the second transistor 5 also turns on, a regenerative current can flow through the coil 3, and the coil 3 is excited. The electromagnet is continuously turned on. Further, after the lapse of the predetermined time T10, the current flowing through the coil 3 with the back electromotive force generated in the coil 3 as a supply source is regenerated by flowing through the second Zener diode 14 of the regenerative circuit 4 and rapidly regenerated. To decrease.

On the other hand, as shown in FIG.
At the time T11 before the time T10 (for example, 1 ms from the time T8) elapses.
When the switch 17 is turned on again in FIG.
As shown in (c), the ON state of the second transistor 5 is maintained. Therefore, as shown in FIG.
A regenerative current flows through the coil 3 until the supply of current from the power source 2 to the coil 3 is restarted, the coil 3 is excited, the ON state of the contact portion U is maintained, and a current flows from the power source V to the load W. Flows.

Accordingly, the electromagnet can be quickly turned off, and the electromagnet is not erroneously turned off depending on the momentary opening of the switch 17.

The voltage across the capacitor 15 to which the second Zener diode 14 is connected in parallel is equal to the power supply voltage V
Even if in varies, the Zener voltage is maintained, so that the amount of charge charged to the capacitor 15 becomes constant, and the amount of charge discharged to the light emitting diode 9 after the application is stopped becomes constant, so that the discharge time becomes constant. . Therefore, by appropriately setting the capacity of the capacitor 15, the predetermined time during which the light emitting diode 9 continues to emit light can be adjusted.

[Second Embodiment] FIG. 4 is a circuit diagram showing a configuration of an electromagnet driving device. In FIG. 4,
Components having substantially the same functions as those of the first embodiment are denoted by the same reference numerals, and only the differences from the first embodiment will be described.

In the present embodiment, in addition to the configuration of the first embodiment, the light emitting state of the light emitting diode 9 is compared by comparing a reference voltage circuit 18 for outputting a reference voltage with a voltage across the capacitor 15. And an internal power supply circuit 20 that outputs an internal power supply voltage Vf for driving the comparator 19 and operating the reference voltage circuit 18.

More specifically, the non-inverting input terminal of the comparator 19 is connected to the other end of the capacitor 15, the inverting input terminal is connected to the reference voltage circuit 18, and the output terminal is connected to the anode of the light emitting diode 9. . The comparator 19 compares the voltage between both ends of the capacitor 15 with the reference voltage. When the voltage between both ends of the capacitor 15 is higher than the reference voltage, the comparator 19 outputs a light emission control signal “high level” and outputs the light emission control signal “high level”. When the “high level” is applied to the light emitting diode 9 and the voltage across the capacitor 15 is lower than the reference voltage, the light emitting control signal “low level” is output, and the light emitting control signal “low level” is applied to the light emitting diode. Is done.

The discharge resistor 13 has one end grounded and the other end connected to the other end of the capacitor 15. That is, the discharging resistor 13 is connected in parallel to the capacitor 15.

Even when the switch 17 is turned off, the internal power supply circuit 20 maintains the output of the internal power supply voltage Vf for a while due to the charging energy stored during the on state. Therefore, even if the switch 17 is turned off, the operation of the comparator 19 and the reference voltage circuit 18 can be continued for a while.

Next, the operation of this embodiment will be described. When the switch 17 is turned on, the power supply voltage Vin of the power supply 2 is changed to the coil 3 and the delay circuit 1 as in the first embodiment.
1 and the pulse signal generation circuit 16 respectively.
The capacitor 15 of the delay circuit 11 is charged via the charging resistor 12. During the charging of the capacitor 15,
When the voltage between both ends of the capacitor 15 becomes higher than the reference voltage of the reference voltage circuit 18, the comparator 19 outputs the light emission control signal “high level”. Then, the light emitting diode 9 emits light, the phototransistor 10 is controlled to be turned on, and the second transistor 5 is controlled to be turned on.

When the switch 17 is turned on, the pulse signal generating circuit 16 operates to generate a pulse signal simultaneously with the above-described series of operations, as in the first embodiment. By controlling the transistor 1 to be turned on and off, the current flowing to the coil 3 is chopper-controlled to maintain a substantially constant value, and the electromagnet continues to be turned on.

Next, when the switch 17 is turned off,
The operation of the pulse signal generation circuit 16 stops, and the first transistor 1 is turned off. Simultaneously with this series of operations, the electric charge charged in the capacitor 15 is discharged via the discharging resistor 13. Accordingly, the voltage across the capacitor 15 decreases from the Zener voltage of the second Zener diode 14 to 0, and while the voltage across the capacitor 15 is higher than the reference voltage of the reference voltage circuit 18,
The comparator 19 outputs a light emission control signal “high level” from the output terminal, and the light emission control signal “high level” is applied to the light emitting diode 9 and the light emitting diode 9 continues to emit light, so that the phototransistor 10 is turned on, Accordingly, the second transistor 5 remains on. At this time, the energy stored in the coil 3 continues to flow through the series circuit of the second transistor 5 and the diode 7 connected in parallel to the coil 3, so that the electromagnet keeps on. Becomes

When a predetermined time elapses after the switch 17 is turned off and the voltage across the capacitor 15 becomes smaller than the reference voltage of the reference voltage circuit 18, the comparator 19 outputs the light emission control signal "low level" from the output terminal. Then, the light emission control signal “low level” is applied to the light emitting diode 9 and the light emitting diode 9 stops emitting light, so that the phototransistor 10 is turned off, and accordingly, the second transistor 5 is also turned off. Therefore, the energy stored in the coil 3 is consumed by flowing a current to a series circuit of the first Zener diode 6 and the diode 7 connected in parallel to the coil 3. The first Zener diode 6 rapidly consumes the energy stored in the coil 3, the current flowing through the coil 3 decreases rapidly, and the electromagnet is turned off.

In this electromagnet driving device, as in the first embodiment, the electromagnet can be quickly turned off when intended, and malfunction does not occur.

As in the first embodiment, by setting the capacitance of the capacitor 15 appropriately, the predetermined time during which the light emitting diode 9 continues to emit light can be adjusted.

Further, the light emitting state of the light emitting diode 9 is controlled by a light emitting control signal output from the comparator 19 by comparing the reference voltage with the voltage across the capacitor 15, not by the voltage across the capacitor 15 which decreases with discharging. Is done. That is, even if the voltage between both ends of the capacitor 15 gradually decreases, the comparator 19 outputs the light emission control signal “high level” to cause the light emitting diode 9 to emit light while the voltage between both ends is larger than the reference voltage. When the voltage becomes lower than the reference voltage, a light emission control signal “low level” is output to stop the light emission of the light emitting diode 9. Therefore, since the light emitting state of the light emitting diode 9 can be controlled with the reference voltage as a boundary, the accuracy of the predetermined time during which the light emitting diode 9 continues to emit light can be increased.

[Third Embodiment] FIGS. 5 to 7 are circuit diagrams showing the configuration of an electromagnet driving device. In FIGS. 5 to 7, parts having substantially the same functions as those of the second embodiment are denoted by the same reference numerals, and only parts different from those of the second embodiment will be described.

In the second embodiment, the second Zener diode 14 is provided, whereas in the present embodiment, the power supply voltage detection circuit 21 is provided.

More specifically, the power supply voltage detection circuit 21 is driven using the internal power supply circuit 20 as a stable power supply, detects the state of voltage application by the power supply 2, and when the power supply voltage Vin is applied, the internal power supply circuit 20 And outputs a constant voltage charge control signal “high level” composed of the internal power supply voltage Vf output when the power supply voltage Vin is not applied.
The power supply voltage detection circuit 21 is provided with a pulse signal generation circuit 16.
And one end of the charging resistor 12.

Next, the operation of this embodiment will be described. When the switch 17 is turned on, the power supply voltage detection circuit 21 detects the voltage application state by the power supply 2 and outputs a constant voltage charge control signal “high level”. The voltage applied to both ends of the capacitor 15 is charged through the charging resistor 12 until the voltage across the capacitor 15 reaches the voltage of the charge control signal “high level”. During the charging of the capacitor 15, the comparator 19
Outputs a light emission control signal “high level” from an output terminal when the reference voltage of the reference voltage circuit 18 connected to the inverting input terminal is higher than the reference voltage, and the light emission control signal “high level” emits light. The light is applied to the diode 9, the light emitting diode 9 emits light, the phototransistor 10 is controlled to be turned on, and the second transistor 5 is controlled to be turned on.

When the switch 17 is in the ON state, the pulse signal generating circuit 16 operates to generate a pulse signal simultaneously with the above-described series of operations, as in the second embodiment. By controlling ON / OFF of 1, the current flowing through the coil 3 is chopper-controlled to maintain a substantially constant value, and the electromagnet continues to be turned on.

Next, when the switch 17 is turned off,
The power supply voltage detection circuit 21 detects the voltage application state by the power supply 2 and outputs a constant voltage charge control signal “low level”, the operation of the pulse signal generation circuit 16 stops, and the first transistor 1 It turns off. Simultaneously with this series of operations, the electric charge charged in the capacitor 15 is discharged via the discharging resistor 13. Capacitor 15
Decreases from the voltage of the charge control signal “high level” to 0, as in the second embodiment,
The electromagnet will remain on.

When a predetermined time elapses after the switch 17 is turned off and the voltage between both ends of the capacitor 15 becomes smaller than the reference voltage, the energy stored in the coil 3 as in the second embodiment. Are the first Zener diode 6 and the diode 7 connected in parallel to the coil 3.
The current flows through the series circuit and is consumed. The first Zener diode 6 rapidly consumes the energy stored in the coil 3, the current flowing through the coil 3 decreases rapidly, and the electromagnet is turned off.

In this electromagnet driving device, the electromagnet can be quickly turned off when it is intended, as in the first and second embodiments, and malfunction does not occur.

Further, similarly to the second embodiment, the light emitting state of the light emitting diode 9 can be controlled with the reference voltage as a boundary, so that the accuracy of the predetermined time during which the light emitting diode 9 continues to emit light can be improved. it can.

The charge state of the capacitor 15 is controlled not by the fluctuating power supply voltage Vin but by a constant voltage charge control signal output by the power supply voltage detection circuit 21 in accordance with the voltage application state by the power supply 2. Even if the power supply voltage Vin fluctuates, the amount of charge charged to the capacitor 15 becomes constant, and the amount of charge discharged toward the light emitting diode 9 after application is stopped becomes constant, so that the discharge time becomes constant. Therefore, by appropriately setting the capacity of the capacitor 15, the predetermined time during which the light emitting diode 9 continues to emit light can be adjusted.

In each of the first to third embodiments, the delay circuit 11 is charged during the application of the voltage by the power supply 2 and goes to the light emitting diode 9 until a predetermined time elapses after the application of the voltage is stopped. And dischargeable capacitor 15
However, the present invention is not limited to such a configuration, and a power supply separate from the power supply 2 and a timer circuit may be used as shown in FIG.

In each of the first and second embodiments, the second Zener diode 14 is connected in parallel to the capacitor 15 in the delay circuit 11. When it is not necessary to make the adjustment of strictly, the second Zener diode 14 may not be connected in parallel, and in that case, the number of parts can be reduced.

Also, as shown in FIG.
Alternatively, the phototransistor 10 may be used as the second transistor 5 in the first to third embodiments. This configuration can omit the second transistor 5 in the first to third embodiments when the current supplied to the coil 3 is relatively small,
The number of parts can be reduced.

Further, as shown in FIG.
May use the photodiode 22 without using the phototransistor 10 in the first to third embodiments. In this case, the photodiode 22 generates a voltage by the light emission of the light emitting diode 9, and turns on the field effect transistor 23.

FIGS. 8 to 11 show modifications of the first embodiment based on the circuit diagram shown in FIG. In FIG. 8, the connection position of the switch section of the regenerative circuit is changed. In FIG. 9, the position of the switching element is set to the plus side of the power supply 2. In FIG. 10, the connection position of the switch section of the regenerative circuit is changed, and the position of the switching element is set to the plus side of the power supply 2. These circuits are also shown in FIGS.
3 (e) and the timing charts shown in FIGS. 3 (a) to 3 (e). In particular, FIG. 1 is a circuit diagram showing a case where a photocoupler 8, which is not always present, is used. A more detailed circuit diagram related to FIG. 10 is shown in FIG. In these examples, when a regenerative current flows, the regenerative circuits in the circuit diagram have the same structure.

The operation of the device shown in FIG. 11 will be described below. When a power supply voltage is applied, the base current of the transistor 5 is supplied from the power supply via the resistor 13, and the transistor 5 is turned on to perform switching control of the coil current. When the application of the power supply voltage is stopped, the charge stored in the capacitor 15 is supplied as the base current of the transistor 5. In this way, the transistor 5 is turned on within a predetermined time, and the attenuation of the coil current can be suppressed.

After a lapse of a predetermined time from the stop of the application of the power supply voltage, the charge stored in the capacitor 15 decreases, and the base current that can keep the transistor 5 on is supplied. Therefore, the transistor 5 is turned off, and the coil current flows through the Zener diode 6 and rapidly attenuates.

The transistor 5 can be a field effect transistor (FET). When using an FET,
The electric charge is stored in the capacitor 15, and a voltage can be applied to the gate of the FET within a predetermined time after the application of the power supply voltage is stopped, so that the FET can be turned on.
After a lapse of a predetermined time, the electric charge stored in the capacitor 15 is discharged, and the voltage applied to the gate also decreases.
Is turned off. Since the photocoupler 8 is generally expensive, an FET is used to reduce the production cost.

The concept of the modified example is also applied in the second and third embodiments of the present invention. Another embodiment described below also achieves the object of the present invention. 13 and 14 showing another embodiment of the present invention, a configuration having characteristics substantially corresponding to those of the components of the first embodiment of the present invention shown in FIG. Elements include a pulse signal generation circuit 16 and a switch section 24.
The same reference numerals are given except for the omission of the photocoupler 8 from FIG.

The operation of the device shown in FIGS. 13 and 14 is the same. When the application of the voltage from the power supply 2 is stopped, a regenerative current flows through the switch section 24 and the regenerative diode 7 to suppress the attenuation of the coil current. Thereafter, when a predetermined time has elapsed, the switch section 24 is turned off, a regenerative current flows through the Zener diode 6 , and the coil current rapidly attenuates.

FIGS. 15A to 15D show the switch 1
7 shows a timing chart of the electromagnet drive device when turning off the switch 7; Similar to the first embodiment of the present invention, time T10 'is 1.5 ms after time T8'.

FIGS. 16 (a) to 16 ( d ) show timing charts of the electromagnet drive device when the application of voltage from the power supply is interrupted unexpectedly and instantaneously. Similar to the first embodiment of the present invention, time T11 ′ is changed to time T8 ′.
1 ms later. Since the photocoupler 8 is generally expensive, the photocoupler 8 is omitted to reduce the production cost.

In these embodiments, the switching frequency and the delay time are 20 kHz and 1.
5 ms. However, the invention is not limited to these values. These values change depending on the inductance and resistance of the electromagnetic coil. When the resistance of the electromagnetic coil is smaller than the inductance, the energy consumed by the resistance of the coil becomes smaller, and when the inductance of the coil is larger, the energy stored in the coil becomes larger. Thus, the amount of temporal attenuation of the regenerative current when the switching element is off (regeneration mode) is reduced. That is, the time required for the coil current to reach the current for opening the electromagnet from the time when the switching is turned off becomes long, so that the switching frequency is small and the delay time can be set long.

If heat generation of the electromagnet coil is not a problem, increasing the average current of the coil holding the electromagnet increases the time for the coil current to reach the current that the electromagnet opens from the time when the switching is turned off. Therefore, the switching frequency can be set low and the delay time can be set long.

[0080]

According to the first, second, seventh, and eighth aspects of the present invention, the delay circuit is provided with a switch unit until a predetermined time elapses even if the application of the power supply voltage is stopped instantaneously. Is kept on, the coil current is regenerated through the switch unit using the back electromotive force of the coil as a supply source, so that the coil is continuously excited and the electromagnet can be kept on. further,
After a lapse of a predetermined time, the current flowing through the coil using the back electromotive force generated in the coil as a supply source is regenerated by flowing through the power absorbing element of the regenerative circuit, and rapidly decreases. Therefore, when intended, the driving of the electromagnet can be quickly stopped, and the coil current can be rapidly attenuated. In the relay, the contact opening speed can be improved and the breaking performance can be improved. Moreover,
In an unintended momentary stop of the power supply voltage, the electromagnet does not malfunction open.

According to a third aspect of the present invention, in addition to the effect of the second aspect of the present invention, the switch section is provided between the transistor provided in parallel with the power absorbing element and a base and a collector of the transistor. And a light emitting diode that emits light so as to control the on / off of the phototransistor, so that the regenerative current can be used as a base current for driving the transistor when the application of the power supply voltage is stopped. Therefore, operation can be performed without requiring a separate power supply for driving the transistors.

According to a fourth aspect of the present invention, in addition to the effect of the second aspect, the capacitor connected in parallel with the Zener diode is maintained at the Zener voltage even when the power supply voltage fluctuates. Since the amount of electric charge charged to the capacitor becomes constant and the current flowing toward the light emitting diode becomes constant after the application is stopped, the discharge time becomes constant. Therefore, by appropriately setting the capacitance of the capacitor, the predetermined time during which the light emitting diode continues to emit light can be adjusted.

According to a fifth aspect of the present invention, in addition to the effect of the second aspect of the present invention, the capacitor outputs not the fluctuating power supply voltage but the power supply voltage detection circuit according to the applied state of the power supply voltage. Since the charge state is controlled by the constant voltage charge control signal, even if the power supply voltage fluctuates, the amount of charge charged to the capacitor becomes constant, and the current flowing toward the light emitting diode after the application is stopped becomes constant. Therefore, the discharge time becomes constant. Therefore, by appropriately setting the capacitance of the capacitor, the predetermined time during which the light emitting diode continues to emit light can be adjusted.

According to a sixth aspect of the present invention, in addition to the effect of the fourth aspect of the present invention, the light emitting diode is not a voltage across the capacitor that decreases as the light emitting diode is discharged. The light emission state is controlled by the light emission control signal output by comparing the above. Therefore, even if the voltage across the capacitor gradually decreases, the light emission state can be instantaneously controlled by the light emission control signal, so that the accuracy of the predetermined time during which the light emitting diode continues to emit light can be improved.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a configuration of a first embodiment of an electromagnet driving device.

FIG. 2 is a timing chart of the electromagnet driving device;
(A) is the state of the switch from the on state to the off state on the way, (b) is the state of the pulse signal, (c) is the state of the second transistor, (d) is the state of the current flowing through the coil,
(E) shows the state of the contact portion.

FIG. 3 is a timing chart of the electromagnet driving device;
(A) is the state of the switch from the on state to the off state and further to the on state on the way, (b) is the state of the pulse signal,
(C) shows the state of the second transistor, (d) shows the state of the current flowing through the coil, and (e) shows the state of the contact portion.

FIG. 4 is a circuit diagram showing a configuration of a second embodiment of the electromagnet driving device.

FIG. 5 is a circuit diagram illustrating a configuration of an electromagnet driving device according to a third embodiment.

FIG. 6 is a circuit diagram showing a configuration of another embodiment of the electromagnet driving device.

FIG. 7 is a circuit diagram showing a configuration of another embodiment of the electromagnet driving device.

FIG. 8 is a circuit diagram illustrating an embodiment.

FIG. 9 is a circuit diagram illustrating an embodiment.

FIG. 10 is a circuit diagram illustrating an embodiment;

FIG. 11 is a circuit diagram illustrating an embodiment;

FIG. 12 is a circuit diagram including a timer circuit.

FIG. 13 is a circuit diagram showing another embodiment.

FIG. 14 is a circuit diagram showing another embodiment.

FIG. 15 is a diagram showing a timing chart of another embodiment.

FIG. 16 is a diagram showing a timing chart of another embodiment.

FIG. 17 is a circuit diagram showing a configuration of a conventional electromagnet driving device.

FIGS. 18A and 18B are timing charts of the electromagnet driving device, wherein FIG. 18A shows a state of a switch in an ON state, FIG. 18B shows a state of a pulse signal, FIG.
(D) shows the state of the contact portion.

FIGS. 19A and 19B are timing charts of the electromagnet driving device, wherein FIG. 19A shows a state of a switch which is turned on from an on state to an off state, FIG. 19B shows a state of a pulse signal, FIG. (D) shows the state of the contact portion.

FIG. 20 is a circuit diagram showing the configuration of a conventional electromagnet driving device.

FIGS. 21A and 21B are timing charts of the electromagnet driving device, wherein FIG. 21A shows a state of a switch which is turned on from an on state to an off state, FIG. 21B shows a state of a pulse signal, FIG. (D) shows the state of the current flowing through the coil, and (e) shows the state of the contact portion.

FIGS. 22A and 22B are timing charts of the electromagnet driving device, wherein FIG. 22A shows the state of the switch from the on state to the off state in the middle and further turns on, FIG. 22B shows the state of the pulse signal, and FIG. (D) shows the state of the current flowing through the coil, and (e) and (f) show the state of the contact.

FIG. 23 is a circuit diagram showing another electromagnet driving device.

FIG. 24 is a diagram showing a timing chart of another electromagnet driving device.

FIG. 25 is a circuit diagram showing another electromagnet driving device.

FIG. 26 is a diagram showing a timing chart of another electromagnet driving device.

[Description of Signs] 1 switching element 2 power supply 3 coil 4 regenerative circuit 5 second transistor 6 power absorption element 7 diode 9 light emitting diode 10 phototransistor 11 delay circuit 14 second zener diode 15 capacitor 16 pulse signal generation circuit 18 reference Voltage circuit 19 Comparator 21 Power supply voltage detection circuit 22 Photodiode 24 Switch section

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FIG. 26

Claims (8)

[Claims] An electromagnet having a coil, a regenerative current flows when voltage application to the electromagnet drive device is stopped, and when a predetermined time has elapsed after the voltage application to the electromagnet drive device has stopped. A regenerative circuit that reduces the regenerative current; and a delay circuit that keeps the on state of the regenerative circuit until the predetermined time elapses after the application of the voltage to the electromagnet drive device is stopped. Electromagnet drive. 2. A switching element connected in series to the coil of the electromagnet, and a switch section and a power absorbing element formed in a parallel circuit in the regenerative circuit, and a diode connected in series to the parallel circuit. The regenerative circuit is configured such that when the switch is turned on and the switching member is turned off from a state in which the switch is on and the switching member is on and a power supply voltage is applied to the coil of the electromagnet, the regeneration is performed. When a current flows through the coil, the power absorbing element rapidly reduces the regenerative current flowing through the coil of the electromagnet when the switch unit is off and the switching element is off. 2. The electromagnet driving device according to claim 1, further comprising: a pulse signal generating circuit for generating the pulse signal. 3. The switch section includes a transistor connected in parallel to the power absorbing element, a phototransistor connected between a base and a collector of the transistor, and emits light to control on / off of the phototransistor. The electromagnet driving device according to claim 2, further comprising a light emitting diode. 4. The delay circuit is charged during application of a voltage to the electromagnetic drive device, and is discharged toward the switch unit until a predetermined time elapses after the application of the voltage to the electromagnetic drive device is stopped. The electromagnet driving device according to claim 2, further comprising a capacitor that can be used, and a Zener diode connected in parallel to the capacitor. 5. The delay circuit is charged during application of a voltage to the electromagnetic drive device, and is discharged toward the switch unit until a predetermined time elapses after the application of the voltage to the electromagnetic drive device is stopped. A power supply voltage detection circuit that applies a predetermined charging voltage to the capacitor when the power supply voltage is higher than a predetermined voltage, and stops applying the voltage to the capacitor when the power supply voltage is lower than the predetermined voltage. The electromagnet driving device according to claim 2, comprising: 6. A reference voltage circuit for outputting a reference voltage, and a comparator for comparing a reference voltage with a voltage across the capacitor to output a control signal for controlling on / off of the switch unit. The electromagnet driving device according to claim 4, wherein: 7. A switching element connected in series to the coil of the electromagnet; a pulse signal generator for generating a pulse signal for turning on the switching element at a predetermined cycle; and the coil of the electromagnet Is provided with the diode connected in parallel to a series circuit of the power absorbing element and the diode, and the regenerative current circuit includes a switch unit and a power absorbing element forming a parallel circuit, and the diode is connected in series with the parallel circuit. The electromagnet drive device according to claim 1, wherein the electromagnet drive device is connected to the first drive unit. 8. A switching element connected in series to the coil of the electromagnet, a pulse signal generator for generating a pulse signal for turning on the switching element at a predetermined cycle, and the power absorbing element. A diode connected in parallel to a series circuit with the coil, wherein the regenerative current circuit has a switch and a power absorbing element forming a parallel circuit, and the diode is connected in series to the parallel circuit. The electromagnet driving device according to claim 1, wherein: