JPS63246027A - Circuit for driving electromagnetic relay - Google Patents

Abstract

PURPOSE:To drive the titled circuit by a single power supply by providing a coil of a single winding self-hold type relay, a capacitor and a switching element short-circuiting across the coil and capacitor in response to the potential of the switching element connected in series to the coil and capacitor. CONSTITUTION:A base of a transistor (TR) QN 10 is controlled directly by an input signal from an input terminal 1. The emitter of the TR QN is connected to ground and the collector is connected to a relay driving power supply +V via a capacitor (C) 4 and a coil (RL) 9 of a single winding self-hold type relay. The TR Q11 is connected in parallel with the RL9 and the C4 connected in series, and controlled by an A/D converter 5 detecting the collector potential of the TR QN 10. Thus, the single winding self-hold type relay is set by a high level signal fed to the terminal 1 and reset by the applied low level signal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a drive circuit for an electromagnetic relay, and more particularly to a drive circuit for a winding self-holding type relay.

[Conventional technology]

Conventionally, a drive circuit for a negative winding self-holding relay has been based on the system shown in FIG. FIG. 3 is a circuit diagram showing an example of a conventional electromagnetic relay drive circuit, and FIG. 4 is a timing chart for explaining its operation. Referring to FIG. 3 and FIG. 4, the collectors of the NPN transistor (hereinafter referred to as QN) 101 and the PNP type transistor (hereinafter referred to as Qp) connected in series are connected to the relay drive power supply element V and one
connected to. Two commonly connected transistors QN
The emitter terminals of IOI and Qp 102 are connected to one terminal of a coil 100 of a single winding self-holding relay. The other terminal of this coil 100 is grounded. In an electromagnetic relay drive circuit with such a configuration, if a high level pulse (a level higher than the ground level) is applied to the base input terminal 103 of QNIOI and the base input terminal 104 of Qp102 is kept at the ground level, QNIOI is turned on and Qp102 is turned off. Therefore, a driving current pulse is applied to the coil 100 in the direction of the arrow 105, and the one-winding self-holding relay is set. Conversely, if a low-level pulse (lower than the ground level) is applied to the base input terminal 104 while keeping the base input terminal 103 at the ground level, QNIOI turns off, Qp102 turns off, and the coil 100 shows the arrow 10.
A drive current pulse is applied in the direction of arrow 106 opposite to 5 to reset the single winding self-holding relay.

[Problem that the invention seeks to solve]

The drive circuit for the conventional single-winding self-holding relay described above requires two types of relay drive power supplies (positive and negative), and
In order to reduce power consumption, the pulse width of the drive pulse applied to the coil of the single-winding self-holding relay has to be generated by a control circuit in the preceding stage of the relay drive circuit.

[Means for solving problems]

The electromagnetic relay drive circuit of the present invention includes one relay drive power source, a coil, a capacitor, and a first switching element of a one-winding self-holding relay connected in series between the relay drive power source and the earth. , a second switching element connected to detect the on/off potential of the first switching element and short-circuit both ends of the coil and the capacitor of the series-connected one-winding self-holding relay; and an A/D converter that turns on/off the second switching element.

[Example] ' Next, the present invention will be explained with reference to FIGS. 1 and 2.

FIG. 1 is a circuit diagram showing an embodiment of an electromagnetic relay drive circuit of the present invention, and FIG. 2 is a timing chart for explaining the operation of FIG. 1.

In FIG. 1, the base of QNIO is directly controlled by an input signal from input terminal 1. The emitter of QNIO is grounded, and the collector is connected to a relay drive power supply +V via a capacitor (hereinafter referred to as C) 4 and a single-winding self-holding relay coil (hereinafter referred to as RL) 9. QNll is connected in parallel to RL9 and RL04 which are connected in series, and is controlled by an A/D converter (hereinafter referred to as Z) 5 that detects the collector potential of QNIO. Referring to FIG. 1 and FIG. 2, input terminal 1
When QNlo is turned on by a high level signal applied to QNlo, its collector potential 6 becomes the earth level, and the ten input terminal potential of Z5 becomes the one input terminal potential to which the relay drive power voltage divided by the resistor 2.3 is applied. becomes lower. Since the output of Z5 is at a low level and no base current is applied to QNII, QNII is turned off. Therefore, a drive current flows through RL9 in the direction of arrow 7, and the one-winding self-holding relay is set. When 04 is thereby charged up, the drive current indicated by arrow 7 disappears, and RL9 is pulse excited.

Next, when a low level signal is applied to input terminal 1, QN
IO is turned off and its collector potential 6 is relay drive power supply +
The potential increases to V. Since the tenth input terminal potential of Z5 is higher than the one input terminal potential, its output becomes high level and QNII is turned on.

That is, RL9. A closed circuit is formed by C4 and QN 11, and the electrical energy charged up in C4 is discharged. Due to this discharge, a drive current is applied to RL9 in the direction of arrow 8, and the one-winding self-holding relay is reset. This drive current indicated by arrow 8 disappears and becomes a pulse when the discharge of C4 ends.

〔Effect of the invention〕

As described above, the present invention has the advantage that the drive circuit for a -winding self-holding relay can be configured with one power supply, and there is no need to generate pulses at the front stage of the relay drive circuit.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing an embodiment of the electromagnetic relay drive circuit of the present invention, Fig. 2 is a timing chart for explaining the operation of Fig. 1, and Fig. 3 is the electromagnetic relay drive circuit of the present invention. FIG. 4 is a circuit diagram showing one embodiment of the present invention, and FIG. 4 is a timing chart for explaining the operation of FIG. 1... Input terminal, 2.3... Resistor, 4... Capacitor (C), 5... A/D converter (Z), 9...
・Coil, 10.11...NPN type transistor (Q
N), 10■... Relay drive power supply. Abandoned I Utsume 2

Claims (1)

[Claims] one relay driving power source, a coil and a capacitor of a one-winding self-holding relay connected in series between the relay driving power source and the earth, and a first switching element;
a second switching element connected to detect the on/off potential of the switching element and short-circuit both ends of the coil and the capacitor of the series-connected one-winding self-holding relay; An electromagnetic relay drive circuit characterized by comprising an A/D converter that turns on/off an element.