JPH04332421A - Drive circuit for relay matrix - Google Patents

Abstract

PURPOSE:To stably actuate driving coils in a column-row designating system by connecting non-linear voltage-drop elements in series to driving coils for a relay arranged in a matrix form. CONSTITUTION:Driving coils RL11-RL33 for a relay are arranged in a matrix form, and are connected in series to non-linear voltage dropping elements ZD11-ZD33, respectively. One side of each series circuit is connected to each other in the column direction, to serve as column side driving terminals DR1-DR3 while the other side thereof is connected to each other in the row direction, to serve as row side driving terminals DC1-DC3. A drive voltage is applied to a predetermined path between the terminals DR1, DC1, and a current is supplied if the voltage is larger than a dropping voltage of the elements ZD12, ZD21, ZD22. When a drive voltage applied to a path where it is not desirable that a current is supplied is set three times or less a dropping voltage of the non-linear voltage dropping element, the object can be achieved. Consequently, the driving coils for the relay arranged in a matrix form can be stably driven in a column-row designating system.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit for stably driving drive windings of relays arranged in a matrix in a matrix designation format.

0002

2. Description of the Related Art FIG. 2 is a diagram for explaining a conventional relay matrix drive circuit.
is the drive winding of the relay, S and R are its terminals, D
R1 to DR3 represent row side drive terminals, and DC1 to DC3 represent column side drive terminals.

When the current flows from the S terminal to the R terminal, the drive winding of the relay drives a relay contact (not shown) in the operating direction, and when the current flows from the R terminal to the S terminal, it drives the relay contact (not shown) in the operating direction. A relay contact (not shown) is driven in the restoration direction.

[0004] To explain the operation using the case of driving the relay drive winding RL11 as an example, the positive side of the drive signal is connected to the row side drive terminal DR1, and the negative side of the drive signal is connected to the column side drive terminal DC1. Relay winding RL11 is driven in the operating direction. At this time, both drive terminals DR1,
Current also flows through the following paths between DC1. i.e.

[
0005]■ DR1→RL12 (S→R)→RL2
2(R→S)→RL21(S→R)→DC1■ DR
1 → RL12 (S → R) → RL32 (R → S) → RL3
1 (S→R)→DC1

[0006] ■ DR1→RL13 (S→R)→RL
23(R→S)→RL21(S→R)→DC1■ D
R1 → RL13 (S → R) → RL33 (R → S) → RL
31 (S→R)→DC1

[0007] Since current also flows through the above-mentioned paths,
The current value of the relay winding must be set so that when a drive signal is directly applied, the relay contacts will be driven in the operating direction, but the relay contacts will not be driven by unwanted current flowing through the above path. .

In particular, when the matrix size becomes large, as is clear from the explanation of the above route, the number of relays passing through the intermediate section increases, that is, the resistance value in this section decreases, and eventually the first and third stages in the above route The maximum value of the current flowing through the drive winding of the second relay reaches 1/2 of the current when it is normally driven.

[0009]

[Problems to be Solved by the Invention] As is clear from the above explanation, it is difficult to set the sensitivity of the relay in the conventional drive circuit.In other words, it is difficult to set the sensitivity of the relay with high precision, so stable operation cannot be achieved. The drawback was that it was particularly difficult to drive a large-scale relay matrix.

[0010] A configuration in which a diode is inserted in series with the drive winding of the relay cannot be applied because the drive in the recovery direction cannot be performed, that is, the current cannot flow from the R terminal to the S terminal.

SUMMARY OF THE INVENTION An object of the present invention is to provide a relay matrix drive circuit which has no restrictions on the current value of the drive winding of the relay and is capable of stable operation.

0012

[Means for Solving the Problems] In order to achieve the above object, in the present invention, a nonlinear voltage drop element is connected in series with the drive winding of a relay arranged in a matrix.

[0013]

[Operation] As a result, current no longer flows through undesired paths in the matrix circuit.

[0014]

Embodiment FIG. 1 is a diagram for explaining an embodiment of the present invention, in which ZD11 to ZD33 are nonlinear voltage drop elements.

The driving windings RL11 to RL33 of the relay are arranged in a matrix, and a nonlinear voltage drop element is connected in series to each driving winding, and one side of the series circuit is connected to each other in the row direction. is connected to the row side drive terminal DR1
~DR3, and the other side of the series circuit is connected to each other in the column direction to form column side drive terminals DC1 to DC3.

The nonlinear voltage drop element is, for example, a bidirectional Zener diode, and its voltage drop is expressed as VZ. In the following, similar to the explanation of the conventional technology, the relay drive winding RL1
The case of driving 1 will be explained as an example.

By connecting the positive side of the drive signal to the row side drive terminal DR1 and the negative side of the drive signal to the column side drive terminal DC1, the relay winding RL11 is driven in the operating direction, and the drive voltage at this time is Voltage required for relay operation (
Operating voltage) Vop and voltage drop VZ of nonlinear voltage drop element
The voltage is selected as the sum of

At this time, for example, DR1→RL12→ZD12→ZD22→RL is connected between both drive terminals DR1 and DC1.
The driving voltage is applied through the path 22→RL21→ZD21→DC1, but in order for the current to flow through this path, three nonlinear voltage drop elements, namely ZD12, ZD22, and ZD2 are required.
1 is inserted in series, a voltage drop of three times or more than VZ is required. In other words, by setting the drive voltage to three times VZ or less, it is possible to prevent current from flowing in an undesired path, achieve stable and reliable drive, and remove restrictions on matrix size. Note that the operating voltage of the relay can be selected to any value as long as it is less than twice VZ.

As is clear from the configuration of FIG. 1, since the circuit does not include a directional element, if the polarity of the drive signal is reversed, current flows through the drive winding of the relay in the opposite direction, that is, from the R terminal to the S terminal. flow, the relay is controlled in the recovery direction. Here, if the relay contact or the magnetic circuit has a self-holding characteristic, the state at the time of application of the control signal will be maintained even after the operation/recovery control signal is stopped.

The nonlinear voltage drop element does not necessarily have to be symmetrical, and a unidirectional Zener diode can also be applied, and the nonlinear element in FIG.
The case of a unidirectional Zener diode in which the current flows in the forward direction toward the terminal will be explained as an example. Note that the voltage drop in the reverse direction of the Zener diode, that is, the Zener voltage, is assumed to be VZR, and the voltage drop in the forward direction is assumed to be 0 V for simplicity.
As in the previous explanation, the explanation will proceed assuming that the drive winding RL11 of the relay is driven.

The driving direction of the relay winding RL11 is D.
R1 → RL11 (S → R) → ZD11 (forward direction) → DC
1 path, and the voltage of the drive signal is selected to be the operating voltage Vop of the relay. For example, DR1 → RL12 → ZD12 (forward direction) → as a path where you do not want current to flow
ZD22 (reverse direction) → RL22 → RL21 → ZD21 (
There is a path (forward direction) → DC1, but if the Zener voltage VZR is selected to be higher than the operating voltage Vop, current flow is prevented.

[0022] The drive in the recovery direction of the relay winding is DC1→Z
The path is D11 (reverse direction) → RL11 (R → S) → DR1, and the voltage of the drive signal is the relay recovery voltage VREL.
and Zener voltage VZR.

[0023] Examples of paths in which current is not desired to flow include, for example, DC1 → ZD21 (reverse direction) → RL21 → RL22.
→ZD22 (forward direction) →ZD12 (reverse direction) →RL12
→ There is a path called DR1, but since two stages of Zener diodes in the opposite direction are inserted in this path, the drive voltage (VREL + VZR) must be selected to be less than twice the Zener voltage VZR, in other words, VZR must be selected to be higher than VREL. If so, current flow is prevented. Generally, the relay operating voltage Vop and the recovery voltage VREL are equal, and this condition can be easily satisfied.

The nonlinear voltage drop element is not limited to the so-called Zener diode type that produces a constant voltage drop, but may also be a switching type, such as a bidirectional thyristor. That is,
The blocking voltage of a bidirectional thyristor is equivalent to the Zener voltage in a Zener diode because if the applied voltage is below the blocking voltage, the element becomes non-conducting. In the case of operation in the path, the element turns on as soon as the current begins to flow, reducing its voltage drop, so that more current can flow through the drive winding of the relay. In other words, the driving voltage only needs to be higher than the blocking voltage of the bidirectional thyristor and higher than the operating voltage, and the driving voltage can be used effectively.

The relay in the above description is not limited to a mechanical so-called electromagnetic relay, but may also be an electronic relay. Furthermore, it goes without saying that the nonlinear voltage drop element may be a circuit that combines a plurality of elements.

[0026]

[Effects of the Invention] As explained above, according to the present invention,
The advantage is that the drive windings of the relays arranged in a matrix can be stably driven in a matrix designation format.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing one embodiment of the present invention.

FIG. 2 is a diagram of a conventional relay matrix drive circuit.

[Explanation of symbols]

Claims (1)

[Claims] 1. A bidirectional nonlinear voltage drop element is connected in series to each of the drive windings of the relays arranged in a matrix, and one side of the series circuit is connected to each other in the row direction to form drive terminals. A drive circuit for a relay matrix, characterized in that the other side of the series circuit is connected to each other in the column direction to serve as the other terminal of the drive terminals.