JPH0443524A - Driving method and driving circuit of electromagnetic relay - Google Patents

Abstract

PURPOSE:To eliminate useless consumption of power and to provide a driving method and a driving circuit of an excellent stability by applying a rating current to a coil until an armature is attracted to an electromagnet, and reducing the applying current to the coil when the attraction of the armature is detected. CONSTITUTION:When an armature 14 is attracted to an electromagnet 13, an operation detecting element 81 is closed, the output signal of a change-over signal generating circuit 8 is made in a high level, the operation of the transistor Tr2 of a change-over switch 9 is stopped, and a current of the level to maintain the operating condition is applied to a coil 12 through a resistance R1. When the armature 14 is separated from the electromagnet 13 while the operating condition is being maintained, the operation detecting element 81 detects the movement of the armature 14 even though the separation time is just an instant, and the output signal of the change-over signal generating circuit 8 is made in a low level. As a result, the rating current is applied to the coil 12 through the transistor Tr2, the armature 14 is attracted to the electromagnet 13, and the operating condition is maintained again.

Description

[Detailed Description of the Invention] [Summary] The present invention relates to a small electromagnetic relay used for controlling electronic equipment, etc., and in particular to a method for driving an electromagnetic relay to reduce power consumption, and eliminates wasted power consumption due to variations in operating speed. In order to provide a drive method and drive circuit with excellent restorability, we have developed a power supply circuit that applies current to the coil of an electromagnet, a motion detection element that is built into an electromagnetic relay and can detect the attraction of the armature by the electromagnet, and a contact. It consists of a switching signal generation circuit that outputs a switching signal when the pole is attracted to the electromagnet, and a switching circuit that switches the current applied to the coil using the switching signal. is applied to the coil, and when the motion detection element detects attraction of the armature by the electromagnet, the current applied to the coil is reduced.

[Industrial application field]

The present invention relates to a small electromagnetic relay used for controlling electronic equipment, and more particularly to a method for driving an electromagnetic relay for reducing power consumption.

Electromagnetic relays are used built into various electronic devices, but since they are driven by integrated circuits, there is a desire to create electromagnetic relays with high sensitivity and low power consumption. In order to realize electrification, improvements have been made such as increasing the number of windings in the coil and reducing the resistance in the magnetic circuit. However, there are limits to the ability to increase sensitivity and reduce power consumption on the electromagnetic relay side, and various improvements have been attempted to achieve lower power consumption in the configuration of the drive circuit.

[Conventional technology]

FIG. 6 is a side sectional view showing an example of an electromagnetic relay, and FIG.
The figure is a circuit diagram showing an example of a conventional drive circuit, and FIG. 8 is a time chart illustrating the operation of the conventional drive circuit.

In FIG. 6, the electromagnetic relay is composed of an electromagnetic relay main body 1 and a contact spring set 2, a fixed base 31 and a cover 3.
It is stored in a container 3 consisting of 2.

The electromagnetic relay main body 1 is composed of an electromagnet 13 consisting of a U-shaped iron core 11 and a coil 12, and an armature 14, and the coil 12 is connected to a coil terminal 15 implanted in a fixed heath 31. Further, the contact spring assembly 2 is composed of a movable contact spring 23 having two movable contacts and a common terminal 22, and fixed contacts 24 and 25 disposed at positions facing the movable contact 21. They are integrated with fixed contact terminals 26 and 27, respectively.

In such an electromagnetic relay, when a driving voltage is applied to the coil 12, the armature 14 is attracted to the electromagnet 13, and the armature 14
moves the movable contact spring 23 to switch the contacts. Further, when the drive voltage applied to the coil 12 becomes lower than a predetermined voltage (referred to as an open voltage), the attractive force of the electromagnet 13 becomes smaller, the armature 14 is opened, and the movable contact spring 23 is restored.

An electromagnetic relay does not operate unless a rated current is applied to the coil at the start of operation, but once it is activated, the operating state is maintained even if the current applied to the coil drops below the rated current.

That is, if the rated current is always applied to the coil, power will be wasted while the operating state is maintained.

Therefore, the conventional electromagnetic relay drive circuit is as shown in Fig. 7.
! A power supply circuit 4 that applies current to the coil 12 of the magnetic relay, and an integrating circuit 53 consisting of a capacitor 51 and a resistor 52
a switching signal generation circuit 5 which outputs a switching signal, and a switching circuit 6 which switches the current to be applied to the coil 12 by the switching signal. The rated current is applied to the coil 12 for an arbitrary time determined by a time constant, and the current applied to the coil 12 is decreased thereafter.

That is, when a signal for operating the electromagnetic relay shown in FIG. 8A is input, the power supply circuit 4 is activated and a current is applied to the coil 12 of the electromagnetic relay, and the signal for operating the electromagnetic relay disappears. The current applied to the coil 12 is also stopped.

When the signal for operating the electromagnetic relay is input, the output signal of the switching signal generating circuit 5 is at a high level as shown in FIG. (A rated current is applied, and a movable contact spring (not shown) moves to switch the contacts.

At the same time, charging of the capacitor 51 of the integrating circuit 53 is started as shown in FIG. 8, and when the voltage of the capacitor 5 reaches the dark value of the transistor 54, the output signal of the switching signal generating circuit 5 becomes as shown in FIG. As shown, it turned to a low level,
At the same time, the current applied to the coil 12 via the transistor 61 is stopped, and as shown in FIG. 8I, a current sufficient to maintain the operating state is applied to the coil 12 through the resistor 62.

The time from when charging of the capacitor 51 of the integrating circuit 53 is started until the voltage reaches the dark value of the transistor 54 is determined by the time constant of the integrating circuit 53 made up of the capacitor 51 and the resistor 52. Therefore, capacitor 51 or resistor 52
By making variable, the time during which the rated current is applied to the coil 12 can be arbitrarily set in accordance with the operation and recovery characteristics of the electromagnetic relay.

[Problem to be solved by the invention]

However, in conventional drive circuits, the time during which the rated current is applied to the coil is set regardless of variations in the operating speed of the electromagnetic relays.For example, if conditions are set so that all electromagnetic relays can operate, the operating speed Drive circuits that target electromagnetic relays with high speeds waste power, and adjusting conditions to suit each electromagnetic relay becomes extremely complicated.

In addition, conventional drive circuits are unable to keep up with short-term opening and closing operations because they always involve discharging the capacitor, and if an impact or the like occurs while the relay is in operation and it becomes open, the electromagnetic relay will not operate unless it is driven again. The problem was that it wouldn't return to normal.

An object of the present invention is to provide a driving method and a driving circuit that eliminate wasteful consumption of power due to variations in operating speed and have excellent restorability.

[Means to solve the problem]

FIG. 1 is a block diagram showing a drive circuit according to the present invention. The same objects are represented by the same symbols throughout the figures.

The above-mentioned problems include a power supply circuit 7 that applies current to the coil 12 of the electromagnet 13, a motion detection element 81 that is incorporated into the electromagnetic relay and can detect the attraction of the armature 14 by the electromagnet 13, and It consists of a switching signal generation circuit 8 that outputs a switching signal when the switch is activated, and a switching circuit 9 that switches the current applied to the coil 12 using the switching signal. This is achieved by the electromagnetic relay driving method and driving circuit of the present invention, which reduces the current applied to the coil 12 when the motion detection element 81 detects the attraction of the armature 14 by the electromagnet 13.

[For production]

In Figure 1, the drive circuit consists of a power supply circuit that applies current to the coil of the electromagnet, an operation detection element that is built into the electromagnetic relay and can detect the attraction of the armature by the electromagnet, and a switching signal when the armature is attracted to the electromagnet. It consists of a switching signal generation circuit that outputs a switching signal, and a switching circuit that switches the current applied to the coil using the switching signal.The rated current is applied to the coil until the armature is attracted to the electromagnet, and the current applied to the coil is When detected, the current applied to the coil is reduced, and the current is switched in accordance with the operating speed of each electromagnetic relay, eliminating unnecessary power consumption.

In addition, since there is no time constant circuit, it is possible to follow short-term opening and closing operations, and even if the electromagnetic relay is opened due to an impact while the operating state is maintained, the rated current will not reach the rated current until the armature is attracted. is applied to the coil and returns to the operating state. That is, it is possible to eliminate wasteful consumption of power due to variations in operating speed, and to realize a driving method and a driving circuit with excellent restorability.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 2 is a circuit diagram showing an embodiment of the drive circuit according to the present invention;
FIG. 3 is a time chart for explaining the operation of the same embodiment, FIG. 4 is a circuit diagram showing a modification of the present invention, and FIG. 5 is a time chart for explaining the operation of the modification.

In FIG. 2, one embodiment of the drive circuit according to the present invention includes a coil 12, a power supply circuit 7 that has a transistor Tr, applies a current to the coil 12, and a switching circuit 9 that switches the current applied to the coil 12. connected in series, switching circuit 9
comprises a transistor Trz and a resistor R1 connected in parallel. A switching signal generation circuit 8 consisting of a NOT circuit is connected to the input side of the transistor Trz, and a set of contact springs driven by an armature, for example, is connected to the operation detection element 81.
It is connected to the input side of the switching signal generation circuit 8.

When the set signal shown in FIG. 3A is input, a current is applied to the coil 12, and when the set signal disappears, the current applied to the coil 12 is also cut off. At the time when such a set signal is input, the motion detection element 81 is open, and the output signal of the switching signal generating circuit 8 is at a low level as shown in FIG. 3B. Therefore, the rated current shown in FIG. 3 is applied to the coil 12 via the transistor Trz, the armature 14 is attracted to the electromagnet 13, and the contacts are switched.

When the armature 14 is attracted to the electromagnet 13, the motion detection element 8
1 is closed, the output signal of the switching signal generating circuit 8 is as shown in Fig. 3B.
As shown in FIG. 3, the transistor Trz of the switching circuit 9 stops operating, and as shown in FIG.
A current sufficient to maintain the operating state through coil 1 flows through coil 1.
2.

If the armature 14 separates from the electromagnet 13 while maintaining the operating state, the motion detection element 81 detects the movement of the armature 14 even if the dissociation period is instantaneous, as shown in FIG. 3B. The output signal of the switching signal generation circuit 8 becomes low level.

As a result, the rated current shown in FIG. 3 (3) is applied to the coil 12 via the transistor Try, and the armature 14 is attracted to the electromagnet 13 to maintain the operating state again.

In the above embodiment, a set of contact springs driven by an armature is connected to the input side of the switching signal generation circuit 80 as the motion detection element 81, but the motion detection element 81 is connected instead of the contact spring set. For example, a photocoupler may be incorporated into an electromagnetic relay, and the optical path may be blocked by a shutter linked to the movement of the armature.

There are two types of self-holding electromagnetic relays: one with one winding and one with two windings, and the drive circuit that applies short pulses to the electromagnetic relay during operation and recovery is complicated in both cases. However, by modifying the drive circuit according to the present invention, short pulses can be applied very easily. For example, Fig. 4(a) shows a drive circuit for a self-holding electromagnetic relay with two windings, and Fig. 4(b) shows a drive circuit for a self-holding type electromagnetic relay with one winding.
This is a drive circuit for a self-holding electromagnetic relay with a winding.

In both cases, the power supply circuit 7 has transistors Tr, and Tra that apply short pulses during operation and recovery, and the switching circuit 9 has AND circuits 91 and 92 connected to the transistors Tr3 and Tr, respectively. A set/reset signal is directly input to 91, and the other AND circuit 92
A set/reset signal is inputted to via the NOT circuit 93. Exclusive O on the input side of AND circuits 91 and 92
A switching signal generation circuit 8 consisting of an R circuit is connected,
Between the input side of the switching signal generation circuit 8 and the ground line, there is a set of contacts, for example driven by an armature, as a motion detection element 81, selected so that the signal level is low when the electromagnetic relay is opened. Spring set is connected.

When the set/reset signal input to the drive circuit shown in FIG. 4(a) becomes high level as shown in FIG. 5A, the AN
The output signal of the D circuit 91 also becomes high level, and the current shown in FIG. 5C is applied to the set coil 12a! The magnetic relay becomes operational. The signal level of the motion detection element 81 is at a low level when the electromagnetic relay is opened, as shown in FIG. 5B, but
During operation, the output signal of the switching signal generating circuit 8 becomes high level and inverted to low level, and the current applied to the set coil 12a is cut off as shown in FIG. 5C.

While the 11vL relay maintains the operating state, the output signal of the switching signal generation circuit 8 is at a low level, and when the set/reset signal becomes a low level as shown in Figure 5A, the reset coil is activated as shown in Figure 5. A current is applied to 12b and the electromagnetic relay becomes open.

The electromagnetic relay is opened, and the output signal of the switching signal generating circuit 8 shown in FIG. 5B becomes low level, and the current applied to the reset coil 12b is cut off as shown in FIG.

When the set/reset signal input to the drive circuit shown in Fig. 4 ω) becomes high level as shown in Fig. 5 A, the AND
The output signal of the circuit 91 also becomes high level, and the current shown in FIG. 5E is applied to the coil 12, so that the electromagnetic relay becomes operational. The signal level of the operation detection element 81 is at a low level when the electromagnetic relay is opened, as shown in FIG. As shown in the figure, the current applied to the coil 12 is cut off.

While the electromagnetic relay maintains its operating state, the output signal of the switching signal generating circuit 8 is at a low level, and when the set/reset signal becomes a low level as shown in FIG. 5A, the coil is activated as shown in FIG. A current in the opposite direction is applied to 12, and the electromagnetic relay becomes open. The electromagnetic relay is opened, and the output signal of the switching signal generating circuit 8 shown in FIG. 5B becomes low level, and the current applied to the coil 12 is cut off as shown in FIG. 5E.

As shown in 2, the drive circuit includes a power supply circuit that applies current to the coil of the electromagnet, a motion detection element that is built into the electromagnetic relay and can detect the attraction of the armature by the electromagnet, and a switching signal when the armature is attracted to the electromagnet. It consists of a switching signal generation circuit that outputs a switching signal, and a switching circuit that switches the current applied to the coil using the switching signal.The rated current is applied to the coil until the armature is attracted to the electromagnet, and the attraction of the armature is detected. Then, by reducing the current applied to the coil, the current is switched in accordance with the operating speed of each electromagnetic relay, eliminating unnecessary power consumption.

In addition, since there is no time constant circuit, it is possible to follow short-term opening and closing operations, and even if the electromagnetic relay is opened due to an impact while the operating state is maintained, the rated current will not reach the rated current until the armature is attracted. is applied to the coil and returns to the operating state. That is, it is possible to eliminate wasteful consumption of power due to variations in operating speed, and to realize a driving method and a driving circuit with excellent restorability.

By using the drive circuit of the present invention, it is possible to reduce the power consumption of an ordinary electromagnetic relay, and to easily drive a self-holding type electromagnetic relay with one winding.

However, if such a drive circuit is constructed on the side that uses the electromagnetic relay, the design of the drive circuit is complicated and there is a large loss in mounting space and assembly time. By integrating the circuit and storing it in the electromagnetic relay container, it is possible to eliminate the complicated design of the drive circuit, the loss of mounting space and assembly time, etc. on the side that uses the electromagnetic relay.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to eliminate wasteful consumption of power due to variations in operating speed, and to provide a driving method and a driving circuit with excellent restorability.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a drive circuit according to the present invention, FIG. 2 is a circuit diagram showing an embodiment of the drive circuit according to the present invention, and FIG. 3 is a time chart for explaining the operation of the same embodiment. , FIG. 4 is a circuit diagram showing a modification of the present invention, FIG. 5 is a time chart for explaining the operation of the modification, FIG. 6 is a side sectional view showing an example of an electromagnetic relay, and FIG. FIG. 8 is a circuit diagram showing an example of a conventional drive circuit, and FIG. 8 is a time chart illustrating the operation of the conventional drive circuit. In the figure, 7 is a power supply circuit, 8 is a switching signal generation circuit, 9 is a switching circuit, 12 is a coil, 12a is a set coil, 12b is a reset coil, 13
is a Ni111 stone, 14 is an armature, 81 is a motion detection element, 91.92 is an AND circuit, 93 is a NOT circuit, R is a resistor, Tr, , TrySTr3, Tr4
represent transistors, respectively.

Claims (1)

[Claims] 1) A motion detection element (81) capable of detecting attraction of the armature (14) by the electromagnet (13) is incorporated into an electromagnetic relay,
A rated current is applied to the coil (12) until the armature (14) is attracted to the electromagnet (13), and the motion detection element (81) detects the movement of the armature (14) by the electromagnet (13). A method for driving an electromagnetic relay, characterized in that when attraction is detected, a current applied to the coil (12) is reduced. 2) A power supply circuit (7) that applies current to the coil (12) of the electromagnet (13), and a power supply circuit (7) that is incorporated into the electromagnetic relay and
a motion detection element (81) capable of detecting attraction of the armature (14) by the armature (13);
); and a switching circuit (9) that switches the current applied to the coil (12) using the switching signal. A drive circuit for an electromagnetic relay.