JPH0817629A - Switch equipment - Google Patents

Abstract

PURPOSE:To reduce a capacitor charging current per unit time, by energizing a load for a specified time, with a specified period, with a first switching element, and supplying a charging current to a capacitor via a second switching element when the load is not energized. CONSTITUTION:An oscillation circuit 2 outputs an ON/OFF periodic signal while a signal is given from a touch switch circuit 1, and the output signal is supplied to a driving circuit 4 though a line C. The oscillation circuit 2 is connected with a control circuit 3 through lines H, I, and electric power is supplied from the control circuit 3. After DC power which is rectified and stabilized in a driving circuit 4 is given through a line D, the control circuit 3 outputs the ON/OFF signal which is so controlled that a controlled voltage obtained through a line E is equal to a specified value, to a line F. The ON/OFF is supplied to a second switching element in a driving circuit 4, through a line F. A line G is a power supply line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switch device suitable for driving a solenoid.

[0002]

2. Description of the Related Art As a conventional switch device, Japanese Patent Publication No.
There was a thing as described in 8-29534 gazette. The one described in this publication turns on / off a transistor by energizing a load (solenoid) connected to a DC power source.
It was controlled by OFF.

[0003]

In the conventional switch device thus constructed, when a load (solenoid) having a low rated voltage of about 12 V to 30 V is used, the current when the load (solenoid) is energized is 12 A ( Since it is large (20 msec conduction), a relatively large current flows through the transistor.
Therefore, the DC power supply needs an output capable of withstanding the large current, and it has been difficult to reduce the size in consideration of heat dissipation measures of the DC power supply and stabilization of the output voltage.

[0004]

According to the present invention, there is provided a first switching element which is provided between a power source and a load and which turns on / off power supply to the load, and a predetermined period of time which is applied to the switching element every predetermined period. An oscillation circuit for outputting a signal for turning on the load is turned on, and the power source is a smoothing capacitor, a second switching element for charging the smoothing capacitor with an electric charge through a reactance, and a terminal of the smoothing capacitor. A control unit that controls ON / OFF of the second switching element within the current capacity of the second switching element so that the voltage is controlled to a predetermined value, and lowers the potential between the reactance and the smoothing capacitor. And a third switching element that is turned on / off in conjunction with the switching element.

[0005]

In the switch device configured as described above, the load (solenoid) can be energized by using the charge charged in the smoothing capacitor, so that the maximum output of the DC power source is consumed by the load (solenoid). There is no need to increase the power.

Further, since the load (solenoid) is energized for a certain period of time every predetermined period, there is always a time during which the load (solenoid) is not energized, so that the power source can charge the smoothing capacitor during this period. It is only necessary to have the capability, that is, the rated output of the power supply can be reduced.

Furthermore, since the second switching element acts to step down the power source voltage and the third switching element acts to step up the power source voltage, a stable low voltage is maintained even if the power source voltage fluctuates. Can be obtained.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a circuit configuration of a switch device of the present invention. In the figure, reference numeral 1 denotes a touch switch circuit, which outputs a signal to an oscillation circuit 2 through a line A when a human body part such as a human hand comes into contact with the touch switch circuit. Line B is a power supply line.

The oscillation circuit 2 maintains oscillation while the signal is given from the touch switch circuit 1. Oscillation cycle is 60
It is 0 msec and outputs an ON signal for 20 msec. That is, a periodic signal that is ON for 20 msec and OFF for 580 msec is output. This ON / OFF output is supplied to the drive circuit 4 via the line C.

The oscillator circuit 2 is connected to the control circuit 3 by lines H and I and is supplied with electric power from the control circuit 3.

The control circuit 3 obtains the DC power rectified and stabilized in the drive circuit 4 through the line D and then obtains the control voltage (the drive voltage of the solenoid 5 is divided by the line E). The ON / OFF signal controlled so that the voltage) becomes a predetermined value is output to the line F. The second switching element in the drive circuit 4 is supplied with this ON / OFF via the line F.
The line G is a power supply line.

FIG. 2 is an electric circuit diagram of the drive circuit 4 shown in FIG. In this figure, T1 and T2 are terminals to which a solenoid (load) 5 is connected. D3 is a diode for absorbing the kickback current of the solenoid 5.

Q2 is a first switching element (FET)
That is, ON / OFF control is performed for the DC power supplied from the smoothing capacitor C2 to the solenoid 5. The switching element Q2 is turned ON / OF by the periodic ON / OFF signal supplied from the oscillation circuit 2 through the line C.
F is controlled.

When the second switching element (switching transistor) Q1 is ON, the capacitor C2 is charged with electric charge through the reactance L1 and the diode D2. Q3 is a third switching element, which is connected between the reactance L1 and the diode D2 and keeps this potential at the ground level when ON.

The terminal voltage (voltage applied to the solenoid 5) of the capacitor C2 is the auxiliary variable resistance VR1 and resistance R.
2. The voltage supplied to the control circuit 3 via the line E can be adjusted by adjusting the variable resistor VR2, which is connected to the ground potential via the variable resistor VR2 and the resistor R3.

DB1 is a diode bridge for full-wave rectification, and AC power supplied between terminals AC (AC24
V) is rectified. This rectified output is smoothed by the resistor R1 and the capacitor C1 and supplied to the control circuit 3 via the line D.

The switching element Q1 is controlled to be ON / OFF based on the ON / OFF signal supplied from the control circuit 3 via the line J and the switching element Q3 is controlled via the line F, and the switching element Q1 is connected to the line G. Electric power is supplied from the control circuit 3 via the control circuit 3. Incidentally, D1 is a diode.

FIG. 3 is an electric circuit diagram of the control circuit shown in FIG. In this figure, IC1 is an IC for switching power supply (MC34063 manufactured by Motorola), and the voltage applied to the terminal (voltage obtained by adjusting the variable resistor VR2 via line E) is applied to the terminal. Signal for controlling ON / OFF of the switching element Q1 from the terminal to ON / O of the switching element Q3
A signal for controlling the FF is output from the terminal. This terminal is connected to the switching element Q1 via the line J, and the terminal is connected to the switching element Q1 via the line F.

The voltage applied to the terminal is made constant by the resistor R6 and the Zener diode ZD1.

Since electric power is supplied to the switching element Q1 of the drive circuit 4 via the resistor R4, the upper limit of the energizing current when the switching element Q1 is ON is regulated by the resistor R4. In this embodiment, the upper limit of the energizing current is set to 0.2 A in consideration of the current capacity of the switching element Q1 and the charging time of the capacitor C2. The capacitor C5 sets the frequency of the internal oscillator.

With this configuration, a step-up / step-down type switching regulator is constructed.

The operation of the step-down switching regulator is such that the input voltage of the switching element Q1 is blocked and the LC composed of the reactance L1 and the smoothing capacitor C2.
Output a square wave with variable duty cycle to the filter. The LC filter averages the square wave to produce a DC output. The output voltage can be adjusted below the input voltage by changing the ON duty ratio with respect to the switching cycle of the switching element Q1. This ON
The duty is changed by the ratio of the control voltage applied to the terminal and the low voltage applied to the terminal.

In the operation of the step-up type switching regulator, energy is stored in the reactance L1 when the switching element Q3 is ON, and this energy is obtained through the switching element Q1 when the switching element Q3 is OFF. LC with DC voltage
Since it is supplied to the filter, the output voltage can be increased by the amount of energy stored in the reactance L1.
The ON duty can be changed similarly to the step-down type.

In the present embodiment, the step-up type and the step-down type are used at the same time so that a stable constant voltage can be obtained even if the voltage of the AC power supplied between the terminals AC changes to either high or low. I am trying to get the voltage.

The operation is performed by switching elements Q1 and Q3.
When is ON, energy is stored in the inductance L1, and when it is OFF, the energy is stored in the diode D1,
D2 is sequentially biased and output to the smoothing capacitor C2 for output. The operation when the switching elements Q1 and Q3 are ON is a step-up type operation, and by substantially stepping down the stepped-up voltage, the voltage supplied to the terminal AC fluctuates up and down. Also keeps the terminal voltage of the capacitor C2 constant (variable resistor VR2)
Can be controlled to the value set by.

Therefore, if the variable resistor VR2 of the drive circuit 4 is adjusted to the left to lower the voltage applied to the terminal, the ON time of the ON / OFF signal output from the terminal becomes longer,
The terminal voltage of the capacitor C2 of the drive circuit 4 becomes high. Conversely, the variable resistor VR2 is adjusted to adjust the switching power supply ICI.
When the voltage applied to the terminal of C1 is lowered, the capacitor C
The terminal voltage of 2 becomes low.

If the terminal voltage of the capacitor C2 is high, the operating voltage applied to the solenoid 5 is high when the switching element Q2 is ON, and the output of the solenoid 5 is strong. For example, if the solenoid 5 is configured to play a pachinko ball, the ball's repelling force becomes stronger.

The resistor R5 and the capacitors C4 and C5 are electronic components for setting the operation of the switching power supply.

FIG. 4 is an electric circuit diagram of the oscillator circuit shown in FIG. In this figure, IC2 and IC3 are general-purpose timer ICs (Timer IC555 made by Sanyo Electric Co., Ltd.), and the constants of the respective ICs are set to output periodic signals as shown in FIG. That is, 20 msec in 0.6 second cycle
This is a signal for outputting the ON signal during the period.

In the figure, C3 is a capacitor for stabilizing the power supply, which supplies DC power with stabilized voltage to the timer ICs IC2 and IC3, and also supplies this power to the touch switch circuit 1 via the line B. are doing.

R7 to R13 are resistors, and C6 to C9 are capacitors, which are connected so that the periodic output as shown in FIG. 5 is obtained from the terminals of the timer ICIC3, and this output is output to the line C. . A resistor R9, a diode D4, and a switch SW1 are connected in series between the terminal of the timer ICIC2 and the ground potential, and also connected to the touch switch circuit via the resistor R9 and the line A.

Therefore, when there is no signal from the touch switch circuit 1 (the signal is at the ground level potential or LOW).
This oscillator circuit 2 stops oscillating when the switch SW1 is closed). That is, the output of the timer ICIC3 remains at the LOW level, and the switching element Q2 of the drive circuit 4 maintains the OFF state.

FIG. 6 shows the touch switch circuit 1 shown in FIG.
It is an electric circuit diagram of. In this figure, 6 is a metal touch electrode, and a person (which can be represented equivalently by a series circuit of a resistor and a capacitor) touches the electrode 6, and an IC for a comparator (an IC having two operational amplifiers incorporated therein). And the resistance R14 to the output of the terminal of the Sanyo Denki LA6358N) IC4 is changed to a HIGH level voltage.
R21, capacitors C10-14, diodes D5, D
6. Zener diode ZD2 is connected. still,
FIG. 7 is an internal wiring diagram of the ICIC4.

Capacitors C13, C are provided between the terminal (inverting input terminal) of the comparator ICIC4 and the touch electrode 6.
An input circuit composed of 14 and the Zener diode ZD2 is provided. This input circuit raises the input impedance of the touch electrode.

A resistor R17 and a capacitor C12 are connected to the inverting input terminal, and the output voltage of the terminal (comparison output) of the comparator ICIC4 is applied to the series circuit of the resistor R17 and the capacitor C12. .

To the terminal (non-inverting input terminal) of the comparator ICIC4, the output voltage of the terminal is applied to the resistors R18 and R19.
The voltage divided by and is applied.

Therefore, the output of the terminal (comparison output) of the comparator ICIC4 is positively fed back to the inverting input terminal and the non-inverting input terminal by the resistors R17, R18, R19 and the capacitor C12, so that a transmitting section is formed. The transmission frequency of this transmission section is determined by the charging / discharging time of the capacitor C12. When a body part comes into contact with the touch electrode 6, the voltage induced in the body is applied to the terminal (non-inverting input terminal) of the comparator ICIC 4 via the touch electrode 6, and the terminal voltage of the capacitor becomes high, so that The transmission frequency becomes high.

The transmission output of the transmission unit (the output of the terminal of the comparator ICIC4) is half-wave rectified through the diode D6 and then given to the terminal (non-inverting input terminal) of the comparator ICIC4. This terminal has a capacitor C10,
The resistor R15 is connected to form a smooth portion.

Therefore, when the transmission frequency of the transmission section is high, the terminal voltage of the capacitor C10, that is, the voltage applied to the terminal (non-inverting input terminal) becomes high. Further, a resistor R14 is connected to the terminal (inversion input terminal) of the comparator ICIC4
The divided voltage (reference voltage) by the resistor R16 is applied. Therefore, when the terminal voltage of the capacitor C10 becomes higher than the reference voltage, the output of the terminal of the comparator ICIC4 rises to the H level voltage, and this output is supplied to the oscillation circuit 2 via the line A.

In the switch device configured as described above, while the touch electrode 6 is being touched by a person, the oscillation circuit 2 continues the periodic oscillation as shown in FIG. In response to this, the switching element Q2 of the drive circuit 4 is turned on, and the solenoid 5 is driven periodically.

The drive power of the solenoid 5 is supplied from the capacitor C2 of the drive circuit 4, and this capacitor C2
Is charged by the switching element Q1 while the solenoid 5 is stopped (while the output of the oscillation circuit 2 is an OFF signal).

That is, the capacitor C2 is the solenoid 5
Since it suffices that the electric charge is charged while the capacitor C2 is stopped, the switching element Q1 for charging the capacitor C2 can have a small current capacity.

For example, the current capacity of the switching element Q1 may be any capacity that can satisfy the electric charge per unit time required to raise the terminal voltage of the capacitor C2 to 24V in 580 msec (= 600 msec-20 msec).

Further, the control circuit 3 and the switching element Q
Considering the switching frequency of the switching power supply circuit composed of 1 etc., the current capacity of the switching element Q1 can be further reduced. At the same time, the output of the switching power supply itself can be reduced.

In this embodiment, when the solenoid is energized for 20 msec, when the switching frequency of the switching power supply is 30 kHz and the ON duty is 0 to 50, the switching element Q2 having a current capacity of 1 A is not radiated. It could be used on a plate.

When a normal three-terminal power supply is used, the switching element Q1 needs to have a current capacity of about 3 A with a heating plate, and it is necessary to take measures for heat dissipation and space distance of the switching element Q1. It is difficult to downsize the device.

[0047]

According to the switch device of the present invention, the load is energized by the first switching element for a certain period of time at a predetermined period, and a smoothing capacitor is used as a power supply for supplying a current to the load. Is performed when the load is not energized via the second switching element, so that there is a margin in the charging time of the capacitor and the capacitor is charged within this time, so the control is performed by the second switching element. The charging current of the capacitor per unit time can be reduced.

Therefore, the heat radiation of the first switching element and the third switching element is reduced, and the overall size of the switch device can be reduced. Further, since the heat generation is reduced, the reliability of the switch device is improved over a long period of time.

[Brief description of drawings]

FIG. 1 is a block diagram showing a circuit configuration of a switch device of the present invention.

FIG. 2 is an electric circuit diagram of a drive circuit 4 shown in FIG.

FIG. 3 is an electric circuit diagram of the control circuit shown in FIG.

FIG. 4 is an electric circuit diagram of the oscillation circuit shown in FIG.

5 is a waveform chart of a signal output from the oscillation circuit shown in FIG.

6 is an electric circuit diagram of the touch switch circuit shown in FIG.

7 is an internal wiring diagram of the comparator IC shown in FIG.

[Explanation of symbols]

 1 Touch Switch Circuit 2 Oscillation Circuit 3 Control Circuit 4 Drive Circuit 5 Solenoid 6 Touch Electrode Q2 First Switching Element Q1 Second Switching Element Q3 Third Switching Element C2 Smoothing Capacitor

Claims (1)

[Claims] 1. A first switching element provided between a power source and a load for turning on / off energization to the load, and energizing the switching element for energizing the load for a predetermined period of time at predetermined intervals. The power supply includes an oscillating circuit that outputs a signal, and the power source controls a smoothing capacitor, a second switching element that charges the smoothing capacitor through reactance, and a terminal voltage of the smoothing capacitor to a predetermined value. As described above, the potential between the control unit for controlling the ON / OFF of the second switching element within the current capacity of the second switching element and the reactance and the smoothing capacitor is lowered to be turned ON in conjunction with the second switching element. / OFF
And a third switching element for controlling the switching device.