RU1778810C - Switching device - Google Patents

Abstract

Usage: in power switching circuits for capacitive and high-current loads. SUMMARY OF THE INVENTION: a switching device comprising limit resistors 1, an electromagnetic neutral relay 2, a self-holding electromagnetic relay 3, on and off windings, a self-holding electromagnetic relay 13, on and off windings and an opening contact 14 connected to the winding circuit are introduced relay 2. which allows to minimize overall mass characteristics and increase the reliability of the device. 1 ill.

Description

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The invention relates to electrical engineering and can be used to switch power to capacitive and high current loads.

A switching device is known comprising two electromagnetic neutral relays, an electromagnetic double-wound polarized relay, a current limiting resistor, alignment resistors, two control switches, terminals for connecting a power source and a terminal for connecting a load, the first terminals of the windings of all relays being combined and connected to the first terminal for connecting the power source, the second terminal of the coil of the electromagnetic neutral relay and the second terminal of the first winding of the electromagnetic polarized relay e are combined, the second terminal of the winding of the second electromagnetic neutral relay through the primary control switch is connected to the second terminal for connecting the power source, the first terminals of the current limiting and equalizing resistors are combined and connected to the terminal for connecting the load, the second terminal of the current limiting resistor through the make contact of the first electromagnetic relay connected to. the second terminal for connecting the power source and with the movable contact of the switching contact group of the first electromagnetic neutral relay, the fixed opening contact of which is connected to the connecting point of the making contacts of the electromagnetic double-wound polarized relay, the second output of each making contact of these is connected to the second output of the corresponding equalizing resistor.

The disadvantage of this device is the low reliability of its operation, due to the fact that the load is disconnected by the parallel connected contacts of the polarized relay. Due to the non-simultaneous opening of the contacts, it is possible that the entire switched current flows through one contact pair.

The closest in technical essence to the invention is a switching device comprising three electromagnetic neutral relays, an electromagnetic double-wound polarized relay, a current limiting resistor, leveling resistors, two control keys, terminals for connecting a power source and a terminal for connecting a load, the first terminals of all relay windings united and connected

with a first terminal for connecting a power source, a second terminal of a winding of a first electromagnetic neutral relay and a second terminal of a first coil of an electromagnetic polarized relay are combined, a second terminal of a winding of a second electromagnetic neutral relay is connected to a second terminal for connecting a power source through a first control key;

0 the first terminals of the current-limiting and leveling resistors are combined and connected to the terminal for connecting the load, the second terminal of the current-limiting resistor through a make contact

5 of the first electromagnetic relay is connected to the second terminal for connecting the power source and to the movable contact of the switching contact group of the first electromagnetic neutral relay, the fixed opening contact of which

0 is connected to the connection point of the make contacts of the electromagnetic double-winding polarized relay, the second output of each make contact from the indicated ones is connected to the second output of the corresponding equalizing resistor, the winding of the third neutral relay is connected to the second output through the second control key to connect the power supply, the make contact of the third relay

0 is connected in parallel with the first control key, the movable contact of the switching contact group of the third relay is connected to the fixed closing contact of the switching contact group

5 of the second electromagnetic neutral relay, the fixed opening contact of the switching contact group of the third electromagnetic neutral relay is connected to the connection point of the second terminals of the winding of the first electromagnetic neutral relay and the first winding of the electromagnetic double-wound polarized relay, the second terminal of the winding is connected to the fixed closing

5 contact switching contact group of the first electromagnetic neutral relay.

The disadvantage of this device is the overestimated overall mass characteristics and low reliability, due to the fact that during the switching of a capacitive load, opening a relay contact connected in series with a current-limiting resistor can

5 occurs before the contact closes, which ensures the connection of circuits with equalizing resistors and contacts of the polarized relay to the power bus. As a result, when the contact is closed,

connecting the circuit with equalizing resistors to the power bus, the current pulse through the contacts of the polarized relay connected in series with the above resistors may exceed the permissible values, which can lead to a malfunction of the device.

The aim of the invention is to minimize the overall mass characteristics, increasing the reliability of the device.

This goal is achieved by the fact that in the switching device containing an electromagnetic neutral first relay with a first make contact, an electromagnetic second relay with self-holding, an on winding, an off winding and two contacts closing when it is turned on, two resistors, two control switches, with a closing contact each, two terminals for connecting a power source and a terminal for connecting a power source and a terminal for connecting a load, the first terminals of the windings of the first and second relays being connected are connected to the first terminal for connecting the power source, the first terminals of the first and second resistors are connected to the terminal for connecting the load, and the second terminal of the first resistor is connected to the second terminal for connecting the power source and to the first terminals of the first contacts of the first and the second control key, introduced the electromagnetic third relay with self-holding, turn-on coil, turn-off coil and a contact that opens when this relay is turned on, the first relay is an additional o is equipped with a second and third make contact, and the first key has an make contact, the second output of the second resistor through the second make contact of the first relay connected to the second output to connect the power source and to the first output of the first contact of the second relay, the second output of this contact being connected to a terminal for connecting the load, the first terminals of the windings of the third relay are connected to the first terminal for connecting the power source, the second terminal of the winding of the first relay is connected to the first terminal of the third contact about the relay, and the second terminal of this contact is connected to the second terminal of the NO contact of the first control key through the NC terminal of the first control key - to the second terminal of the winding of the first relay, through the third NO terminal of the first relay is connected to the second terminal to connect the power source, and through the second the contact of the second relay is with the second output of the OL winding of the third relay, while the second terminals of the switching windings of the second and third relays are connected to the second terminal of the make contact of the second control key laziness.

This makes it possible to control the moment of closing the contacts of the first electromagnetic relay with self-retention, to ensure the optimal operation of the contacts and, as a result, the long-term passage of the load current through them, which allows to improve the overall mass characteristics of the device through the use of more small switching elements.

The drawing shows a switching device.

The device contains limiting resistors 1, an electromagnetic neutral first relay 2, an electromagnetic second relay 3 with self-holding, on and off windings, first and second make contacts 4 of the first relay 2, the first terminal 5 for connecting the power source, the terminal for connecting the load 6, the first the make contact 7 of the second relay 3, the first 8 and second 9 control keys, the second pin 10 for connecting the power source, the third make contact 11 of the first relay 2, the second make contact 12 of the second relay 3, the third electric self-holding magnetic relay 13, on and off windings and its opening contact 14, with the first outputs of the windings of all relays 2, 3, 13 connected to the first output 5 of the power source, the second output of the first relay 2 through the opening contact 14 of the third relay 13 connected to the first the output of the third make contact 11 of the first relay 2, the other output of the contact 11 of the relay 2 is connected to the second output of the power supply 10, the first output of the first control key 8 is connected to the second output of the switching winding of the second relay 3, the second output of the first key 8 the control board is connected to the first terminal of the third make contact 11 of the first relay 2, the third terminal of the control key 8 is connected to the second terminal of the power supply 10, the second terminals of the trip windings of the polarized relays 3 and 13 are connected to the first terminal of the second control switch 9, the second terminal of the switch 9 - the voltage is connected to the second terminal 10 of the power source, the second terminal of the turn-on coil of the third relay 13 through the second make contact 12 of the second relay 13 is connected to the first terminal of the third make contact 11 of the first relay 2, the first

the terminals of the limiting resistors 1 are connected to the terminal for connecting the load 6 and to the first terminal of the make contact 7 of the second relay 3, the second conclusions of the limit resistors 1 through the make contacts 4 of the first relay 2 are connected to the second output of the make contact 7 of the second relay 3 and with the second output power source.

The device operates as follows.

When the control key 8 is closed, the electromagnetic neutral first relay 2 is activated and closes its contacts 4 and 11, Contacts 4 connect the load 6 via current-limiting resistors 1 to the second terminal 10 of the power source. The process of charging the load capacitance begins, and the charging current is defined as the sum of the currents of the parallel branches, each of which is formed by the serial connection of the contact 4 of the relay 2 and the current-limiting resistor 1. The current of the individual branch is determined by the permissible current through the contact 4 of the relay 2 and is limited to set value by selection of resistor 1. Contact 11 of relay 2 shunts the first control key 8 and provides the on state of relay 2 after resetting key 8 to its initial state.

Upon completion of the charging of the load capacitance 6, the first control key 8 is reset. The second terminal of the turn-on coil of the second relay 3 is self-holding via the first control switch 8 and the closed contact 11 of the first relay is connected to the second terminal 10 of the power source, the second relay 3 is activated and closes its make contacts 7 and 12. Previously turned on first relay 2 remains on, t .to. the second terminal of its winding through terminal 11 of this relay is still connected to terminal 10 of the power source.

The closed contact 7 of the second relay 3 shunts the serially connected contacts 4 of the first relay 2 m current limiting resistors 1, providing the connection of the charged load capacitance 6 to the output 10 of the power source. The second terminal 12 of the second relay 3 connects the second terminal of the winding. The third relay 13 is self-holding via the closed terminal 11 of the first relay 2 to the terminal 10 of the power source. The third relay 13 is activated and opens its previously closed contact 14, thereby disconnecting the winding of the first relay 2 from the output 10 of the power source. The first relay 2 is disconnected and opens its own contact 11, de-energizing the winding of the third relay 13. Contacts 4 of the first

relay 2 opens and further power to load b is provided through closed contact 7 of second relay 3.

Thus, the proposed device eliminates the possibility of premature opening of contacts, ensuring the passage of the charging current of the load capacitance.

In order to disconnect the power supply to the load, it is necessary to close the second control switch 9. The second terminals of the trip windings of the second and third relays 3 and 13 are self-holding connected to terminal 10 of the power supply and these relays are turned off. Contact

5 7 of the second relay 3 opens and breaks the load supply circuit 6. Contact 14 of the third relay 13 closes and prepares the circuit for subsequent switching on. The control key 9 opens and the circuit goes

0 to the initial state.

A positive effect is achieved by providing a predetermined mode of operation of the contacts of the polarized relay and eliminating the possibility of the appearance of current pulses

5 through said contacts during capacitive load switching.

Claims (1)

SUMMARY OF THE INVENTION Switching device comprising an electromagnetic neutral first 0 relay with a first closing contact, an electromagnetic second relay with self-holding, an on winding, an off winding and two contacts closing when this relay is turned on, 5 two resistors, two control keys, each with a make contact, two terminals for connecting a power source and a terminal for connecting a load, the first terminals of the windings of the first and second relays 0 are connected to the first terminal for connecting the power source, the first terminals of the first and second resistors are connected to the terminal for connecting the load, and the second terminal of the first resistor through the first 5, the make contact of the first relay is connected to the second output for connecting the power source and to the first outputs of the make contacts of the first and second control keys, different 0 in that, in order to minimize overall mass characteristics and increase reliability, an electromagnetic third relay with self-holding, a turn-on winding, a turn-off winding and a contact opening when this relay is turned on is inserted into the device, the first relay is additionally equipped with second and third make contacts, and the first key is an NC contact, and the second second resistor through the second for 9 177881010 the make contact of the first relay is connected to the contact of the first control key, through with a second terminal for connecting the source-disconnect contact of the first key of the power adapter and with the first terminal of the first circuit with the second terminal of the winding contact of the second relay, and the second you turn on the first relay, through the third gate of this contact is connected to the output for 5 contact contact of the first relay with the second connecting the load, the first terminals by the terminal for connecting the power source of the third relay are connected to the first one. and through the second contact of the second relay with an output for connecting the pita source with the second output of the switching winding nor, the second terminal of the winding of the first relay relay, while the second terminals are connected to the first terminal of the contact of the third-10 turn-off coil of the second and third relays its relay, and the second terminal of this contact is co-connected to the second terminal of the closing is one with the second terminal of the second contact of the second control key.