SU777747A1 - Relay switching apparatus testing device - Google Patents

Description

The invention relates to reference measurement technology, can be used in switches for various purposes, for example, in measurement switches to control the failure of any relay and the simultaneous operation of two or more relays caused by a malfunction in the switch control circuit or for other reasons. It can also be used to protect a device connected to a switch, such as an object of control in metering switches, while two or more relays are triggered simultaneously.

Devices are known that detect the failure of any relay and, at the same time, the operation of two switch relays, in which monitoring is carried out by periodically polling the state of contact 1.

However, in the touch circuit, control and protection of the switch is not provided between control cycles, i.e., in the operating mode, and the amount of control equipment is proportional to the number of switch channels.

Also known are devices in which reliable activation of one and only one relay is provided by memorizing the fact of a relay operating and resolving the operation of the second relay only after the previous 2 is turned off.

However, in such a scheme, a significant complication of the control circuits 5 by the switch is required.

The closest solution to the technical essence and the achieved result to the invention is a device in which the control and protection of the switch

10 is performed by analyzing the magnitude of the current consumption of the switch through the power supply circuit and turning off the supply voltage of the switch when the current consumption exceeds the set value using a special high-speed key circuit 3.

However, this device has a reduced reliability due to the considerable complexity caused by the necessity of 20 gating the analysis and indication circuit with a special signal generated by the gate formation circuit.

The aim of the invention is to increase the reliability of the device, as well as to simplify its design.

This goal is achieved by the fact that a device for controlling relay switches containing a power source, a control circuit, terminals for connecting a controlled switch, a two-source

thirty

reference voltages, two comparison circuits and an analysis and indication circuit, a controlled stabilized current source is introduced, which has two inputs and one output, one of its inputs connected to a power source, another input connected to the output of the analysis and display circuit, and the output connected with a terminal for connecting a monitored switch and inputs to the comparison circuits.

The drawing shows the proposed device.

The device for controlling relay switches contains a circuit / control connected to a controlled relay switch 2, the supply circuit of which includes a controlled constant current source 3, the output of which is also connected to one input of the comparison circuits 4 and 5, and the other inputs to which are connected 5 and 7 reference voltages, and the inputs of the comparison circuits are connected to the analysis and indication circuit 8, the output of which is connected to the control input of the controlled source 3.

The control device operates as follows.

Regardless of the number of relays in the monitored relay switch connected by the / circuit, the supply current of the switch 2 is constant and determined by the source 3, therefore the voltage at the inputs of the comparison devices 4 and 5 depends on the number of the connected circuit / relay. If the signals from circuit 1 are absent, then the voltage on the power bus of switch 2 is almost equal to the supply voltage. If the circuit / gives a signal to turn on one relay, then the voltage on the power bus, mutatpra 2 is equal to the product of the value of the current of source 3 and the resistance of the winding of one relay.

If the circuit produces signals for switching on several relays (failure of the control circuit), then the voltage on the power bus of switch 2 is equal to the product of the current of source 3 and the resistance of parallel connected relay windings connected by circuit /.

The voltages of source 6 and 7 are chosen so as to reliably distinguish between the three above listed states of switch 2. The status of this switch is indicated by circuit 8. In the initial state, when there are no signals from the circuit / source 5 is turned off.

The magnitude of the current generated by source 3 is chosen to provide

triggered, taking into account the spread and change in the characteristics of the relay, of only one of the relays connected by circuit 1, which at the same time provides protection for the device connected to the com mutator 2.

In order to increase the reliability of the indicated protection, circuit 8, when two or more relays are triggered, shuts down the controlled source 5, reducing the supply current of the switch 2.

The use of the invention contributes to the simplification of the measuring and control equipment, enhancing reliability.

Claims (3)

1. Debt B-. A. Switching devices of automatic control systems, M., “Energie, 1969. 2. USSR author's certificate, 0 447773, cl. H 01 H 47/00, 1973. 3. USSR author's certificate, L 199258, cl. H 01 H 47/00, 1966 (irotype). ;