JPH02247930A - Low power consumption relay driving circuit - Google Patents

Abstract

PURPOSE:To make it possible to drive a relay with a low power consumption by connecting a short circuit opening means to open a short of a current limiter in parallel with the current limiter after operation of a relay. CONSTITUTION:After a relay 10 is connected in parallel with a current limiter 30, the limiter 30 is shorted by a short circuit opening means 40 in an inoperative condition of the relay 10. When a switching means 20 is turned on in that condition, the current limiter 30 is shorted by the current limiter 30 at the moment that the switching means 20 is ON, so that a power source voltage Vs is applied to the relay 10 and the relay 10 is in an ON state. When the relay 10 is in an ON state, the short circuit opening means 40 which has been shorting the current limiter 30 is opened, and the current limiter 30 is connected in series to the relay 10, so that the power consumption can be reduced because a current flow decreases.

Description

[Detailed Description of the Invention] [Summary] Regarding a circuit that drives a relay with low power consumption, in order to reduce heat generation during operation of the relay, a low power consumption relay drive that can drive the relay with low power consumption is provided. For the purpose of providing a circuit, a relay, switching means for intermittent power supply for driving the relay, and current limiting means for limiting the current of the relay after operation are connected in series between power supplies, A short-circuit opening means is provided in parallel with the current limiting means to short-circuit the current limiting means when the relay is inactive and to open the current limiting means when the relay is active.

[Industrial application field]

The present invention relates to a circuit that drives a relay with low power consumption.

2. Description of the Related Art Control information output devices used in various control devices often use a large number of relays and output a large amount of information through the relay contacts.

In such a case, a large number of relays are mounted in a concentrated manner, which increases power consumption and temperature rise, and requires a power supply device with a large power supply capacity.

Conventionally, low power consumption drive circuits using relays are
Some use latching relays that can maintain their state even if the relay's drive power is turned off.

However, when controlling a mechanical system, latch relays may cause problems. If this happens, you will not be able to instruct the camera to stop, and the camera will continue to rotate. Therefore, in such a case, it is better to use a normal relay circuit, which stops the camera operation if the wiring to the relay is disconnected.

[Conventional technology]

FIG. 4 shows a diagram illustrating a conventional example.

The conventional example shown in FIG. 4 includes a relay 10, a spark killer diode 11 connected in parallel to the relay 10 for absorbing back electromotive force generated in the relay 10, and a switching system that cuts off and on the power supply to the relay 10. It consists of a transistor 21 and an input resistor 22 connected to the base of the switching transistor 21 and inputting an input signal.

In this circuit, when an input signal is applied from the input terminal to the switching transistor 21 through the input resistor 22, the switching transistor 21 is turned on, and voltage Vs (5V) is applied to the relay 10 (here, the switching transistor 21 is in the on state). resistance at is negligible).

When the input signal continues to be on, the voltage Vs (5V) is continuously applied to the relay 10.

[Problem to be solved by the invention]

In the conventional circuit, when the relay 10 continues to operate, the rated voltage is continuously applied to the relay 10, which increases power consumption and heat generation.

In addition, when a large number of relays 10 are used, the relay 1
The capacity of the power supply unit for driving 0 is also required to be large.

In order to reduce heat generation during operation of the relay, the present invention has the following features:
An object of the present invention is to provide a low power consumption relay drive circuit that can drive a relay with low power consumption.

[Means to solve the problem]

FIG. 1 shows a block diagram explaining the present invention in detail. In the principle diagram of the present invention shown in FIG. 1, a relay 10, a switching means 20, and a current limiting means 30 are connected in series between power supplies. The current limiting means 30 includes a relay 1.
After operation 0, step 1, the short circuit of the current limiting means 30 is opened. A short-circuit release means 40 is connected in parallel, and providing such a means is a means for solving this problem.

[For production]

Usually, the voltage applied to a relay is 70 to 75% or less of the rated voltage, and the open voltage of most relays is 5% or more.

Therefore, the rated voltage may be applied to the relay 10 during operation, and an appropriate voltage between the rated voltage and the open circuit voltage may be applied during the holding state.

For this purpose, the relay 10 and the current limiting means 30 are connected in series, and the current limiting means 30 is short-circuited by the short-circuit opening means 40 when the relay 10 is not in operation.

When the switching means 20 is turned on in this state, the moment the switching means 20 is turned on, the current limiting means 30 is turned on by the short-circuit opening means 40.
Since the relay 10 is short-circuited by the power supply voltage V
s is applied, and the relay 10 is turned on.

When the relay 10 is turned on, the short-circuit release means 40 that short-circuited the current limiting means 30 is opened, and the current limiting means 30 is connected in series with the relay 10, so the current decreases and power consumption is reduced. becomes possible.

[Examples] The gist of the present invention will be specifically explained below with reference to Examples shown in FIGS. 2 and 3.

FIG. 2 is a diagram illustrating the present invention in detail, and FIG. 3 is a diagram illustrating a time chart of an embodiment of the present invention. Note that the same reference numerals indicate the same objects throughout the figures.

The embodiment of the invention shown in FIG.
A spark killer diode 11 for absorbing the back electromotive force generated during the zero operation, and a switching transistor 21 as the switching means 20 explained in FIG.
In this example, the input resistor 22 is configured with a current limiting means 30, a Zener diode 3 as a short-circuit opening means 40, and a break contact 41 of a relay 10.

Here, the rated voltage of the relay 10 is assumed to be 5V, and the Zener voltage of the Zener diode 31 is assumed to be 2.5V.

Here, when the voltage shown in (a) in FIG. 3 is applied to the switching transistor 21 through the input resistor 22, the switching transistor 21 is turned on, and a power supply voltage of 5V is applied to the relay 10, so that the relay 10 is turned on. .

When the relay 10 is turned on, the break contact 41 is turned off as shown in (C), the Zener diode 31 is connected in series to the relay 10, and a voltage of 2.5 cm is applied to the Zener diode 31 as shown in (B). Therefore, 2.5V is applied to the relay 10, the current is halved, and the power consumption is also halved.

Since the open circuit voltage is about 5% of the rated voltage, relay 10
If the voltage applied to is 0.5V, the holding state can be maintained, but in this example, it is maintained at 2.5V in order to guarantee sufficient reliability against vibrations, etc. There is.

In this way, the rated voltage is applied only when the relay is operating, and 1/2 of the rated voltage is applied during the holding state, but when many relays are operated at the same time, a large amount of power is required only when the relay is operating. Since a large-capacity power supply is required, when operating a large number of relays, the operating time of the relays (
The capacity of the power supply device can also be reduced by controlling the supply of input signals by shifting the input signals by approximately 1 to 5 m5.

Zener diodes are used as current limiting means, but
When using multiple relays with the same rated voltage but different resistance values at the same time, for example to set the power consumption to 172, you can use a resistor to connect multiple relays with the same resistance value as each relay. However, since it is possible to use a Zener diode whose Zener voltage is half the rated voltage of the relay, only one type of Zener diode is required. Become.

(Effects of the Invention) According to the present invention as described above, it is possible to provide a low power consumption relay drive circuit that can reduce the power consumption in the holding state of the relay by half with a simple circuit configuration.

[Brief explanation of drawings]

FIG. 1 is a block diagram explaining the present invention in detail, and FIG. 4 is a diagram explaining a conventional example. In the figure, 10 is a relay 11 is a spark killer diode, 20 is a switching means, 21 is a switching transistor, 22 is an input resistor, 30 is a current limiting means, 31 is a Zener diode, 40 is a short-circuit opening means, 41 is a relay The break contacts of are shown respectively. Vs (+5V) Fig. 2 Detailed explanation of the present invention Fig. 3 A diagram illustrating a time chart of an embodiment of the invention Fig. 3 Power supply voltage ○ Block diagram detailed explanation of the present invention Fig. 1 Vs (+5V) Conventional Figure i14 explaining an example

Claims (1)

[Claims] A circuit for driving a relay (10) with low power consumption, comprising: the relay (10); a switching means (20) for intermittent power supply for driving the relay (10); and the relay. A current limiting means (30) for limiting the current after operation of (10) is connected in series between the power sources, and the relay (10) is connected in parallel with the current limiting means (30).
1. A low power consumption relay drive circuit, comprising short-circuit opening means (40) that short-circuits the current limiting means (30) in a non-operating state and opens the current limiting means (30) in an operating state.