SU584390A1 - Device for automatic change-over to standby power supply - Google Patents

Description

one

The invention can be used in installations for supplying power for various purposes, in particular in installations for remotely supplying DC voltage to communication equipment.

Power backup devices and a 1J redundant power supply system are known.

And the closest to the invention, the technical solution is a device for automatically entering a reserve of power sources containing its switching unit to a single vI electromagnetic relay installed in the circuit of each power supply 2. The disadvantages of this device are the inability to use it for alternately replacing several main sources of power supply with different values of high output voltage by one backup source, as well as the presence of one electromagnetic relay, constant but finds luminant under basic voltage source for controlling it, which creates the danger of false rejection primary source and limits the output voltage source.

The aim of the invention is to expand the field of application of the device in a network with sources of different voltages and to increase the reliability of its operation. This is achieved by the fact that the automatic installation of the voltage at the output of the backup source is additionally introduced into the proposed device;

on, the output of the main source and the blocking element. In addition, the switch unit is supplemented with a second electromagnetic relay and a control circuit, the first and second inputs of which are connected respectively to the coils of the electromagnetic relays, the contacts of one relay are designed to disconnect the main source from the load, and the contacts of the other to disconnect the backup source.

connected to the automatic installation unit, and the other is combined with the similar outputs of other switching units and connected to the input of the blocking element, some of the inputs of which are connected to the first

inputs of control circuits of switching units, and others with control units of the presence of the voltage of the main sources.

The drawing is a block diagram of the described device.

The device contains the main 1 and backup 2 power sources, control units 3 and switching units 4 according to the number of main sources, blocking element 5, unit 6 of automatic voltage setting at the output of backup source 2, load 7, V

Composition Oloka switch includes two relays 8 II 9 II scheme 10 control 1 l. The control unit 3 is designed to control the supply voltage at the main source output and generate an excitation signal for the switching unit 4 transmitted through the blocking element 5. The automatic voltage setting unit 6 at the backup source output includes a circuit for determining the required output voltage . The blocking element is intended to block the outputs of the control units when the backup source is connected to any load 7.

During normal operation and the nominal value of the output voltage of the main source 1 its output is connected to the input of the unit

3 control and through the normally closed contacts of the relay 8 and the normally open contact of the relay 9 of the unit 4 with the load 7. In this case, the relays 8 and 9 are de-energized. In the case of a voltage drop (or a large underestimation) at the output of the main source, the control unit 3 generates a signal, which through the blocking element 5 enters the relay 8 of the unit

4 and scheme 10 of the control. Relay 8 disconnects the load 7 from the output of the main source. The control circuit 10 generates a sigal for switching on the relay 9, for operating the block, its element 5 and for controlling the block b. The relay 9 connects the load 7 to the output of the backup source 2. The llo signal from block 6 at the output of the reserve source is set to the same voltage as the output of the main source.

The response time of the device is determined by the response time of relays 8 and 9.

For operation of the device a source of 24 V dc current is required.

Thus, the proposed device allows the use of a single backup source to alternately replace several primary sources with different output biases. The required voltage level at the output of the backup source is set automatically, which allows a significant expansion in the field of application of the device. Using the control unit and separate relays to connect to the load of the main and backup sources instead of one relay, which is permanently

under the current of the main source, increases the operability of the device, provides galvanic isolation between the outputs of the main and backup sources, and also eliminates the risk of false rejection of the main source.

The use of the proposed device makes it possible to increase the reliability of the communication lines by reducing the time required for the introduction of a reserve of power sources as compared to manual transmission, which significantly affects the time for just the communication lines.

Claims (2)

1. Patent of Great Britain No. 1306748, cl. P 02J 9/00, 1972. 2. USSR author's certificate No. 402988, cl. P 02J 9/06, 1973.