JP4552847B2 - 2-wire electronic switch - Google Patents

Description

  The present invention relates to a two-wire electronic switch for turning on and off the power supply from an AC power supply to a load, and it is necessary to secure an operating power supply by itself.

  Conventionally, as a switch to turn on / off the power supply from the AC power supply to the load, a non-contact switching element such as a thyristor or a triac is inserted into the power supply path from the AC power supply to the load as a load switching unit with the digitization of the wiring equipment. However, there is provided a type (first conventional switch) that electrically opens and closes (turns on and off) the contactless switching element using an electronic circuit. The first conventional switch needs to secure its own operating power supply (circuit power supply) because the electronic circuit drives the non-contact switching element when a person operates the operation unit (operation switch). Therefore, the first conventional switch has a configuration in which wiring is performed by three lines or four lines.

  However, from the viewpoint of reduced wiring, when a two-wire wiring is a general wiring device, the first conventional switch cannot individually draw in the power source wire when connected to the AC power source and the load by the two wires. As a result, securing a self-operating power supply became a problem.

  In order to solve the above problem, a two-wire electronic switch (2 wire electronic switch that enables two-wire wiring in a state in which a contactless switching element is used as a load switching unit while being connected in series with an AC power source and a load. A second conventional switch) has been proposed. A configuration almost similar to that of the second conventional switch is disclosed in Patent Document 1.

  The operation of the second conventional switch will be described with reference to FIG. FIG. 4 is a circuit diagram of a second conventional switch. In the second conventional switch 9, a triac 90 as a load switching unit is connected in series with the AC power source AC and the load L. First, when the control signal from the control output terminal 910 of the control unit 91 becomes low level, the second power supply unit 92 is turned off. At this time, the third power supply unit 93 supplies power to the first power supply unit 94. In this state, the gate current (drive signal) of a magnitude necessary to turn on the triac 90 does not flow through the gate (drive signal input terminal) of the triac 90, so the triac 90 is turned off (opened). The power supply from the AC power supply AC to the load L is cut off.

On the other hand, when the control signal from the control output terminal 910 of the control unit 91 becomes a high level, the second power supply unit 92 is turned on. As a result, the second power supply unit 92 supplies power to the first power supply unit 94. At this time, when charging of the first power supply unit 94 is completed, a current flows from the charging completion detection unit 920 to the auxiliary opening / closing unit 95, and the auxiliary opening / closing unit 95 is turned on (closed). When the auxiliary opening / closing unit 95 is turned on, a current having a magnitude necessary for turning on the triac 90 flows to the triac drive unit 96, and a gate current flows from the triac drive unit 96 to the triac 90. Thus, the triac 90 is turned on (closed), and power is supplied from the AC power supply AC to the load L.
JP 2001-227804 A (pages 2 to 5 and FIG. 7)

  However, the second conventional switch 9 has a problem that the load current flowing through the load L vibrates. More specifically, when power is supplied from the AC power supply AC to the load L, the second conventional switch 9 first charges the first power supply unit 94 to secure an operating power supply (see FIG. 5). At times t1 to t2 and t4 to t5), the auxiliary opening / closing part 95 is turned on, and then the load opening / closing part (triac 90) is turned on. At this time, each time the path of the load current in the second conventional switch 9 is switched, the impedance of the second conventional switch 9 changes, so that the load voltage of the load L changes greatly. The load current also changes according to the change in the load voltage. Here, as shown in FIG. 5, when the polarity of the load current is reversed, the load switching unit is changed from the on state to the off state, the first power supply unit 94 is charged again, and the auxiliary switching unit 95 is turned on. And the cycle of turning on the load switching unit is repeated. By repeating the cycle, the load current is in a vibrating state (time t2 to t3, time t5 to t6 in FIG. 5).

  The present invention has been made in view of the above points, and an object of the present invention is to provide a two-wire electronic switch that can reduce vibration of a load current flowing in a load.

The invention according to claim 1 is a two-wire electronic switch that is connected to an AC power source and a load by two wires and secures its own operating power source based on the AC power from the AC power source. A load opening / closing unit that is inserted into a power supply path to the load and that switches electrical opening and closing between both ends, and operates with electric power based on the AC power, and switches the electrical opening and closing of the load opening and closing unit from the AC power source A control unit that outputs a control signal for controlling power supply to the load; a first power source unit that serves as an operation power source of the control unit; and power converted from the AC power based on the control signal. The second power supply unit to be supplied to the first power supply unit, and whether the charging of the first power supply unit is completed when power is supplied from the second power supply unit to the first power supply unit. a charge completion detector for detecting as to whether or not, in the closed state By Rukoto, an auxiliary closing unit to switch the electric opened and closed with respect to the load switching unit, the auxiliary switching unit, that the charge of the first power supply portion by the charge completion detecting section is completed The closed state is continued until a certain period of time has elapsed from when the load opening / closing portion is detected to a level at which the vibration of the load current flowing through the load that occurs when the load switching unit is closed is not zero-crossed. And

In this configuration, after securing the operating power supply of the self-by auxiliary switching unit until the elapse of the predetermined period to maintain a closed state, it is possible to reduce the vibration of the load current. Thereby, it can be used by connecting to various loads.

According to a second aspect of the present invention, in the first aspect of the present invention, when the charging completion detection unit detects that the charging of the first power supply unit is completed, the predetermined period elapses. A pulse generation circuit section for outputting a pulse signal for closing the auxiliary opening / closing section to the auxiliary opening / closing section is provided on a connection side with the auxiliary opening / closing section. In this configuration, a device that outputs a pulse signal for maintaining the closed state of the auxiliary opening / closing unit to the auxiliary opening / closing unit can be configured by an inexpensive logic IC.

According to a third aspect of the present invention, in the first aspect of the present invention, when the charging completion detection unit detects that the charging of the first power supply unit is completed, a detection signal is sent to the control unit. When the detection signal is input, the control unit outputs to the auxiliary opening / closing unit a pulse signal for closing the auxiliary opening / closing unit until the predetermined period elapses . In this configuration, since the control unit outputs a pulse signal for closing the auxiliary opening / closing unit, the number of components can be reduced.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, when the load switching unit is in an open state and the power supply from the AC power source to the load is stopped. In addition, a third power supply unit that supplies power converted from the AC power to the first power supply unit is provided. In this configuration, even when power supply from the AC power supply to the load is stopped, power can be reliably supplied to the control unit.

  According to the present invention, it is possible to reduce the vibration of the load current flowing through the load.

(Embodiment 1)
An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a circuit diagram of a two-wire electronic switch according to the first embodiment. FIG. 2 is a diagram illustrating the operation of the two-wire electronic switch according to the first embodiment.

  First, the basic configuration of the first embodiment will be described. The two-wire electronic switch A according to the first embodiment secures its own operating power source based on AC power from the AC power source AC. As shown in FIG. 1, a load switching unit 1, a rectifying unit 2, The control unit 3, the first power supply unit 4, the third power supply unit 5, the second power supply unit 6, the charging completion detection unit 7, and the auxiliary opening / closing unit 8, and the AC power supply AC and the load Two lines are connected in series with L. The AC power supply AC is, for example, a commercial power supply of 100V. The load L is, for example, a lighting device including a fluorescent lamp or an incandescent bulb, a ventilation fan, or the like.

  The load opening / closing unit 1 includes a triac 10 and a triac drive unit 11. The triac 10 is formed of, for example, a semiconductor such as silicon, and switches electrical opening and closing between the two terminals 100 and 101 according to a gate current (drive signal). The TRIAC 10 is connected in series with an AC power source AC and a load L via terminals 12 and 13 and a filter inductor 14. The triac 10 and the inductor 14 are connected in parallel with the surge absorbing element 15 and the filter capacitor 16, respectively. On the other hand, the triac drive unit 11 includes a resistor 110 and a capacitor 111 connected in parallel, and is connected to the gate (drive signal input terminal) of the triac 10 at one end and to the terminal 101 of the triac 10 at the other end. ing. Further, the triac drive unit 11 is connected in series with a thyristor 80 of the auxiliary opening / closing unit 8 described later via the rectifying unit 2. When the thyristor 80 is turned on (closed), the current flowing through the triac drive unit 11 increases, and a gate current having a magnitude necessary for turning on the triac 10 flows through the gate of the triac 10. In the first embodiment, when the triac 10 is turned on (closed), the circuit is made up of the AC power supply AC, the triac 10, the inductor 14, and the load L, and power is supplied to the load L to operate the load L. On the other hand, when the triac 10 is turned off (opened), power is not supplied to the load L, and the operation of the load L is stopped.

  The rectifying unit 2 is a diode bridge composed of four diodes, and is connected to the AC power supply AC and the load L via the terminals 12 and 13 at the input end, and the third power supply unit 5 and the second power supply unit at the output end. 6 and the auxiliary opening / closing part 8. The rectification unit 2 performs full-wave rectification on AC power from the AC power supply AC, and outputs the full-wave rectified power to the third power supply unit 5, the second power supply unit 6, and the auxiliary opening / closing unit 8.

  The control unit 3 is a microcomputer that outputs a control signal for switching electrical opening and closing of the triac 10 from the control output terminal 30 to the second power supply unit 6 by, for example, a human operation. The control unit 3 operates with electric power from the first power supply unit 4. In addition, the control unit 3 is provided with an operation unit (operation switch) (not shown) such as a tact switch, which is operated by a person, and the control signal is output every time the operation unit is operated. 2 to the power supply unit 6 of the second. The control signal is a binary signal having a high level and a low level, and the control unit 3 outputs a high-level control signal when the triac 10 is turned on, and when the triac 10 is turned off. Outputs a low level control signal. Thereby, the control unit 3 controls power supply from the AC power supply AC to the load L.

  The first power supply unit 4 is an operation power supply for the control unit 3, and includes a buffer capacitor 40, a three-terminal regulator 41, a capacitor 42, and a capacitor 43 connected in parallel from the input end side. The input terminal is connected to the third power supply unit 5 and the second power supply unit 6, and the output terminal is connected to the input terminal of the control unit 3. The buffer capacitor 40 is charged with power from the third power supply unit 5 and the second power supply unit 6 and smoothed by removing the ripple component. The three-terminal regulator 41 stabilizes the direct-current voltage of the buffer capacitor 40 to, for example, 3V. From the above, the first power supply unit 4 supplies stable power to the control unit 3.

  The third power supply unit 5 includes, in order from the input end side, a current-limiting resistor 50, an NPN transistor 51, and a resistor 52 connected in series, and is connected to the output end of the rectifying unit 2 at the input end. In addition, the first power supply unit 4 is connected on the output end side. The third power supply unit 5 includes a bias resistor 53 connected between the base and collector of the transistor 51 and a Zener diode 54 whose cathode is connected to the base of the transistor 51. The base of the transistor 51 is grounded via a Zener diode 54. The impedance conversion of the third power supply unit 5 is performed according to the on state and the off state of the transistor 51. The third power supply unit 5 receives AC power from the AC power supply AC via the rectifying unit 2 when the triac 10 is turned off and power supply from the AC power supply AC to the load L is stopped. The power is received as full-wave rectified power, is converted into power whose size is regulated by the Zener diode 54, and the converted power is supplied to the first power supply unit 4. At this time, the load current in the two-wire electronic switch A is divided into a current flowing through the first power supply unit 4 and a current flowing through the Zener diode 54, both of which are finally connected to the rectifying unit via the ground. 2 and returns to the AC power source AC via the load L. The load current at this time is large enough to prevent the load L from malfunctioning. Further, the current consumption of the control unit 3 is kept low, and the impedance of the third power supply unit 5 is kept high.

  The second power supply unit 6 includes, in order from the input end side, a PNP transistor 60 and a diode 61 connected in series, connected to the output end of the rectifying unit 2 at the input end, and the first at the output end. Is connected to the power supply unit 4 of That is, the second power supply unit 6 is connected in parallel with the third power supply unit 5. The second power supply unit 6 includes a resistor 62 and a capacitor 63 connected between the base and emitter of the transistor 60, and a resistor 64 and an NPN transistor 65 connected to the base of the transistor 60. Further, the second power supply unit 6 includes a resistor 66 connected between the base and emitter of the transistor 65. The transistor 65 has an emitter grounded and a base connected to the control output terminal 30 of the control unit 3. The transistor 65 controls the on / off state of the transistor 60. The second power source unit 6 receives AC power from the AC power source AC as full-wave rectified power via the rectifier unit 2 based on a control signal from the control unit 3, and receives the power as the first power source. The power is supplied to the power supply unit 4. A specific procedure will be described. When a high-level control signal is received from the control unit 3, the transistor 65 is turned on. Accordingly, the transistor 60 is turned on. At this time, the impedance of the two-wire electronic switch A decreases. Thereafter, the second power supply unit 6 supplies power to the first power supply unit 4. In contrast, when a low level control signal is received from the control unit 3, the transistor 65 is turned off and the transistor 60 is also turned off. As a result, the second power supply unit 6 stops supplying power to the first power supply unit 4.

  The charging completion detection unit 7 includes a Zener diode 70 and a pulse generation circuit unit 71. The Zener diode 70 is connected to the DC voltage of the buffer capacitor 40 of the first power supply unit 4 when the power is supplied from the second power supply unit 6 to the first power supply unit 4. When the input voltage is increased and charged, and the cathode potential becomes higher than the zener voltage, a detection signal is output to the pulse generation circuit unit 71 to detect that the charging of the first power supply unit 4 is completed. The pulse generation circuit unit 71 is constituted by an inexpensive logic IC, for example, and is arranged on the connection side with the auxiliary opening / closing unit 8. When a detection signal is input from the Zener diode 70, the pulse generation circuit unit 71 generates a pulse signal for turning on a thyristor 80 of an auxiliary switching unit 8 described later for a certain period of time, and drives a thyristor of the auxiliary switching unit 8 described later. Flow to section 81. The fixed period for turning on the thyristor 80 is the time until the load current does not zero-cross even when the load current oscillates, and is set appropriately according to the application. Note that if the predetermined period is about 1 to 3 msec, current consumption can be reduced.

  The auxiliary opening / closing unit 8 includes a thyristor 80 and a thyristor driving unit 81. The thyristor 80 is connected to the output terminal of the rectifying unit 2 and is also connected to the input terminals of the third power supply unit 5 and the second power supply unit 6. The thyristor drive unit 81 includes a resistor 810 and a capacitor 811 connected in parallel, one end connected to the gate of the thyristor 80 and the pulse generation circuit unit 71, and the other end connected to the cathode of the thyristor 80. While the thyristor driving unit 81 receives a pulse signal from the pulse generating circuit unit 71, the thyristor driving unit 81 supplies a gate current having a magnitude necessary for turning on the thyristor 80 to the thyristor 80. As a result, the load current flowing from the rectifying unit 2 to the second power supply unit 6 flows from the rectifying unit 2 to the thyristor 80, and the auxiliary opening / closing unit 8 connects the triac 10 to the triac driving unit 11 of the load opening / closing unit 1. The triac 10 is switched to the on state by passing a gate current of a magnitude necessary for turning on to the triac 10.

  Next, the operation of the two-wire electronic switch A of Embodiment 1 will be described. First, an operation in a state where the power supply from the AC power supply AC to the load L is not performed (off state) will be described. When the control signal of the control unit 3 becomes low level, the transistor 65 and the transistor 60 of the second power supply unit 6 are turned off. On the other hand, the third power supply unit 5 supplies power to the first power supply unit 4. As a result, the first power supply unit 4 serves as an operating power supply for the control unit 3. In this state, the gate of the triac 10 does not have a gate current of a magnitude necessary for turning on the triac 10, so the triac 10 is turned off and operates from the AC power supply AC to the load L. Insufficient power is supplied.

  Next, an operation in a state where the power supply from the AC power supply AC to the load L is performed (on state) will be described. When the control signal of the control unit 3 becomes a high level, the transistor 65 and the transistor 60 are turned on, and the second power supply unit 6 supplies power to the first power supply unit 4. As a result, the first power supply unit 4 serves as an operating power supply for the control unit 3. On the other hand, when the input voltage of the first power supply unit 4 increases and the cathode potential of the Zener diode 70 becomes higher than the Zener voltage, the pulse generation circuit unit 71 outputs a pulse signal to the thyristor driving unit 81 for a certain period. Thereafter, while the thyristor driving unit 81 receives the pulse signal, a gate current having a magnitude necessary for turning on the thyristor 80 is supplied to the thyristor 80, and the thyristor 80 is turned on. As a result, the load current flowing from the rectifying unit 2 to the second power supply unit 6 flows from the rectifying unit 2 to the thyristor 80. After that, the triac drive unit 11 causes a gate current of a magnitude necessary to turn on the triac 10 to flow to the gate of the triac 10, and the triac 10 is turned on.

  Here, when the triac 10 is turned on, a load current flows through the triac 10, but when the zero cross point is reached, the arc is turned off and turned off. When the triac 10 is turned off, a load current flows again from the rectifying unit 2 to the first power supply unit 4 through the second power supply unit 6 to secure an operating power supply for the two-wire electronic switch A. That is, the operation of securing the operating power supply is performed every half cycle of the AC power from the AC power supply AC.

  As shown in FIG. 2, the pulse generation circuit unit 71 outputs a pulse signal for a certain period of time (time t2 to t4 in FIG. 2) by the operation in a state where power is supplied from the AC power supply AC to the load L. , T6 to t8), the thyristor 80 is kept on for a certain period. At this time, even if the path of the load current is switched from the thyristor 80 to the triac 10, the change in the load current is small because the voltage change in the two-wire electronic switch A is relatively small. Since the load current increases during a certain period in which the thyristor 80 is kept on, the load current is less likely to zero cross (time t2 to t3, t6 to t7 in FIG. 2), and the vibration of the load current is reduced. be able to.

  As described above, according to the first embodiment, the oscillation of the load current flowing in the load L can be reduced by maintaining the thyristor 80 of the auxiliary opening / closing unit 8 for a certain period after securing its own operating power supply. it can. As a result, the two-wire electronic switch A can be used by being connected to various loads L. Moreover, what outputs the pulse signal which maintains the ON state of the thyristor 80 to the thyristor drive part 81 of the auxiliary | assistant opening / closing part 8 can be comprised by cheap logic IC. Furthermore, even when the power supply from the AC power supply AC to the load L is stopped, the third power supply unit 5 can reliably supply power to the control unit 3.

(Embodiment 2)
A second embodiment of the present invention will be described with reference to FIG. FIG. 3 is a main part circuit diagram of the two-wire electronic switch of the second embodiment. Note that a and b in FIG. 3 are connected to the rectifying unit 2 in a and b in FIG.

  As shown in FIGS. 1 and 3, the two-wire electronic switch B according to the second embodiment includes a load opening / closing unit 1, a rectifying unit 2, a first power supply unit 4, a third power supply unit 5, and a second power switch. Although the power supply unit 6 and the auxiliary opening / closing unit 8 are provided in the same manner as the two-wire electronic switch A of the first embodiment, the following characteristic portions that are not included in the two-wire electronic switch of the first embodiment are provided. is there.

  The two-wire electronic switch B according to the second embodiment includes a control unit 3a and a charge completion detection unit 7a as illustrated in FIG. 3 instead of the control unit 3 and the charge completion detection unit 7 according to the first embodiment. The charging completion detection unit 7a is not connected to the auxiliary opening / closing unit 8, but is connected to the control unit 3a. The charging completion detection unit 7a is charged when the DC voltage of the buffer capacitor 40 of the first power supply unit 4 increases when power is supplied from the second power supply unit 6 to the first power supply unit 4. When the cathode potential becomes higher than the Zener voltage, it is detected that charging of the first power supply unit 4 is completed by outputting a detection signal to the control unit 3a.

  On the other hand, when the detection signal is input from the charging completion detection unit 7a, the control unit 3a outputs a pulse signal for turning on the thyristor 80 of the auxiliary opening / closing unit 8 to the thyristor driving unit 81 of the auxiliary opening / closing unit 8 for a certain period. In addition, the control part 3a is the same as that of the control part 3 (refer FIG. 1) of Embodiment 1 in points other than the above.

  Next, the operation of the two-wire electronic switch B of the second embodiment will be described. The operation in a state where the power supply from the AC power supply AC to the load L is not performed (off state) is the same as that in the first embodiment. Next, an operation in a state where the power supply from the AC power supply AC to the load L is performed (on state) will be described. When the control signal of the control unit 3 becomes a high level, the second power supply unit 6 supplies power to the first power supply unit 4 as in the first embodiment. Thereafter, when the charging of the first power supply unit 4 is completed, the charging completion detection unit 7a sends a detection signal to the control unit 3a. When the control unit 3a receives the detection signal from the charging completion detection unit 7a, it outputs a pulse signal to the thyristor driving unit 81 for a certain period. Thereafter, as in the first embodiment, while the thyristor driving unit 81 receives a pulse signal, a gate current is supplied to the thyristor 80, and the thyristor 80 is turned on. After that, the triac drive unit 11 causes a gate current of a magnitude necessary to turn on the triac 10 to flow to the gate of the triac 10, and the triac 10 is turned on.

  As described above, according to the second embodiment, since the control unit 3a outputs a pulse signal that turns on the thyristor 80 of the auxiliary opening / closing unit 8, the number of components can be reduced.

  As a modification of the first and second embodiments, the load opening / closing unit may include a thyristor instead of the triac. Even if it is such a structure, there exists an effect similar to Embodiment 1,2.

  As another modification of the first and second embodiments, when the triac is turned on and when the triac is turned off, the control unit outputs a pulsed control signal to the second power supply unit, The second power supply unit may supply power to the first power supply unit based on the control signal. Even if it is such a structure, there exists an effect similar to Embodiment 1,2.

1 is a circuit diagram of a two-wire electronic switch according to a first embodiment of the present invention. It is a figure which shows operation | movement of a 2 wire type electronic switch same as the above. It is a principal part circuit diagram of the 2 wire type electronic switch of Embodiment 2 by this invention. It is a circuit diagram of the conventional 2-wire type electronic switch. It is a figure which shows operation | movement of a 2 wire type electronic switch same as the above.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Load switching part 10 Triac 11 Triac drive part 2 Rectification part 3 Control part 4 1st power supply part 6 2nd power supply part 7 Charging completion detection part 70 Zener diode 71 Pulse generation circuit part 80 Thyristor 81 Thyristor drive part

Claims (4)

A two-wire electronic switch that is connected to an AC power source and a load with two wires and secures its own operating power source based on the AC power from the AC power source,
A load switching unit that is inserted into a power supply path from the AC power source to the load and switches electrical switching between both ends;
A controller that operates with power based on the AC power, and outputs a control signal that controls power supply from the AC power supply to the load by switching the electrical switching of the load switching unit;
A first power supply unit serving as an operation power supply for the control unit;
A second power supply that supplies power converted from the AC power to the first power supply based on the control signal;
A charging completion detection unit that detects whether or not charging of the first power supply unit is completed when power is supplied from the second power supply unit to the first power supply unit;
An auxiliary opening / closing part that switches the electrical opening / closing with respect to the load opening / closing part by being in a closed state ;
The auxiliary opening / closing part is a load current that flows in the load that is generated when the load opening / closing part is closed after the charging completion detecting part detects that the charging of the first power supply part is completed. A two-wire electronic switch characterized in that the closed state is continued until a predetermined period of time determined that the vibration of the motor reaches a level at which zero crossing does not occur . When the charging completion detection unit detects that the charging of the first power supply unit is completed, a pulse signal for closing the auxiliary opening / closing unit until the predetermined period elapses is output to the auxiliary opening / closing unit 2. The two-wire electronic switch according to claim 1, further comprising a pulse generation circuit section that is connected to the auxiliary opening / closing section. When the charging completion detection unit detects that the charging of the first power supply unit is completed, a detection signal is output to the control unit,
The two-wire according to claim 1, wherein when the control unit inputs the detection signal, the control unit outputs a pulse signal to the auxiliary opening / closing unit to close the auxiliary opening / closing unit until the predetermined period elapses. Electronic switch.   When the power supply from the AC power source to the load is stopped when the load opening / closing unit is in an open state, a third power that supplies power converted from the AC power to the first power source unit The two-wire electronic switch according to claim 1, further comprising a power supply unit.

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