KR950004177Y1 - Dc solenoid driving circuit - Google Patents

Abstract

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Description

DC Solenoid Drive Circuit

1 is a circuit diagram for explaining a conventional direct current solenoid driving.

2 is a circuit diagram for explaining the DC solenoid driving of the present invention.

3 is an output waveform diagram of FIG.

* Explanation of symbols for main parts of the drawings

1: power supply unit 2: first constant voltage circuit

3: constant voltage unit 4: second constant voltage circuit

5: switching part 6: control part

IC1: Micom

The present invention relates to a solenoid (Direct Current Solenoid), and more particularly to a direct current solenoid drive circuit that can simplify the power supply device for driving a direct current solenoid.

Conventional DC solenoid driving circuit is composed of a power transformer (PT1), a bridge die (BD1), a capacitor (C1) to generate a DC power by converting AC power and rectifying and smoothing the AC power as shown in FIG. A power supply unit 1, a constant voltage unit 3 formed of a first constant voltage circuit 2 and a capacitor C2 that are smoothed while maintaining the voltage for the solenoid S1 by receiving power from the power supply unit 1, and the constant voltage unit A second constant voltage circuit 4 that receives the constant voltage of (3) and maintains the voltage for the microcomputer IC1, and a microcomputer IC1 that receives the constant voltage of the second constant voltage circuit 4 and generates a solenoid drive signal; And a switching unit 5 consisting of resistors R1 and R2, a transistor Q1, and a diode D1 receiving the signal of the microcomputer IC1 and switching with the constant voltage unit 3. It is composed of a solenoid S1 connected between the sections 5 and driven according to the switching action of the switching section 5.

As the power transformer PT1 of the power source unit 1 according to the related art thus converts AC into a required voltage, a direct current including a pulse flow component is generated via the bridge diode BD1 and the capacitor C1.

Therefore, when the voltage through the constant voltage unit 3 and the second constant voltage circuit 4 is applied to the microcomputer IC1, the microcomputer IC1 generates the solenoid S1 driving signal as necessary, so that the switching unit 5 Since the transistor Q1 is turned on when the driving signal is high, the voltage across the capacitor C2 of the constant voltage unit 3 is applied across the solenoid S1 so that the solenoid S1 is driven.

However, the resistors R1 and R2 are current limiting and noise preventing resistors, respectively, and the diode D1 is a diode for protecting the transistor Q1.

However, in this conventional technique, since the solenoid S1 driving current continuously consumes a current of several 100 mA, the power supply unit 1 and the first constant voltage circuit 2 must be brought down to a large current, thereby increasing the capacity of each power supply device. The heat sink for heat dissipation must be installed.

The present invention has been made in view of the above-described drawbacks, and has an object to provide a direct current solenoid driving circuit capable of simply realizing a power supply by reducing the current consumption of the solenoid after driving the solenoid.

Hereinafter, an embodiment of the present invention for achieving such an object will be described in detail with reference to the accompanying drawings.

2 is a DC solenoid driving circuit of the present invention, a power supply unit 1 for transforming an AC power source to generate a DC power source, and a constant voltage unit that receives the power supply of the power supply unit 1 and maintains the voltage for driving the solenoid S1 ( 3), a second constant voltage circuit 4 that receives the constant voltage of the constant voltage unit 3 and maintains the voltage for the microcomputer, and a microcomputer that receives the constant voltage of the second constant voltage circuit 4 and generates a solenoid drive signal. (IC1), the switching unit 5 which performs a switching action in response to the signal of the microcomputer IC1, and is connected between the switching 5 and the constant voltage unit 3 in accordance with the switching action of the switching unit 5 The driving solenoid S1 is the same as the conventional one, and is connected in parallel with the switching unit 5 so as to drive the solenoid S1 for a time constant period and then limit the current of the solenoid S1 (R4 to R6). , Control part 6 comprising capacitor C3, transistor Q2, diode D3 It is composed of

Referring to FIG. 3 of the present invention configured as described above, the power supply unit 1 generates a direct current including a pulsation component across the capacitor C1, and the microcomputer IC1 is a constant voltage unit 3 and a second constant voltage circuit 4. When the solenoid receives a direct current through and generates a driving signal when necessary, the principle of driving the solenoid S1 by switching by the transistor Q1 of the switching unit 5 is the same as in the related art.

The control unit 6 receives the solenoid drive signal of the microcomputer IC1 and gradually increases the potential of the point “C” during the time delay, that is, the time constant of the resistor R4 and the capacitor C3, and after the time constant period. Since transistor Q2 is turned on, transistor Q1 of switching unit 5 is turned off so that current I of solenoid S1 is limited by resistor R7, so that current I is greater than current during time constant period. Becomes smaller.

That is, in FIG. 3, when the transistors Q1 and Q2 are turned off, the "F" and "I" sections are used. When the microcomputer IC1 generates the solenoid drive signal, the "G" and "H" sections are used. When the transistor Q1 is turned on and the transistor Q2 is turned off in the interval, and the transistor Q1 is turned off and the transistor Q2 is turned on in the "H" section, the potential of the point "A" of FIG. 2 is equal to that of FIG. As shown in (B), the potential of the point "B" is high in the "G" region as shown in (B) (the voltage between the base and emitter of the 5V transistor Q1) × It is as high as the voltage between the base and emitter of transistor Q1 and then as low as the forward voltage of voltage + diode D2 between collector and emitter of transistor Q2 in the " H "

Also, the point potential "C" gradually increases in the "G" section as shown in (C), and gradually decreases in the "I" section, and the "D" point potential is high only in the "G" section, so as shown in (E), the solenoid ( Since the current I of S1) is high only in the "G" section, the current I of the solenoid S1 becomes large in the "G" section and decreases in the "H" section as shown in (E).

During the initial driving time (delay time) as described above, the current I After time delay, the current I to be.

As described above, the present invention flows a large amount of current only in the solenoid S1 and limits the current after a time delay, thereby simplifying a power supply for driving the solenoid S1, thereby reducing costs and reducing weight. .

Claims (1)

A power supply unit 1 for generating a DC power supply, a constant voltage unit 3 for generating a voltage for driving the solenoid S1 under the power of the power supply unit 1, and a microcomputer IC1 for receiving the voltage of the constant voltage unit 3. A second constant voltage circuit 4 for generating a potential voltage, a microcomputer IC1 generating a solenoid driving signal in response to the voltage of the second constant voltage circuit 4, and a signal of the microcomputer IC1 for switching operation. Connected to the switching unit 5, the constant voltage unit 3 and the switching 5, and driven in parallel to the switching unit 5 and the solenoid S1 driven according to the switching action of the switching unit 5. Connected to delay the output signal of the microcomputer IC1 for a predetermined time, and then connected in parallel to the solenoid S1 and the switching unit 5 to delay the output signal of the microcomputer IC1 for a predetermined time, and then to the solenoid S1. DC solenoid, characterized in that consisting of a control unit 6 for controlling to distribute the current The load driving circuit.