SU1387060A1 - Device for arcless commutation of electric circuit - Google Patents

Abstract

The invention relates to electrical engineering, namely to the switching of an electrical circuit of both a constant and an alternating current. The aim of the invention is to increase the reliability and simplification of the device. When a control pulse is applied to input 7, contact 11 of relay 1 turns on, then sensor 19 of relay's core 1 is activated, which causes power semiconductor switch 10 to turn on, and then contacts 12 of relay 2 are closed. When a control pulse is applied to turn off input 8, power semiconductor switch 10, contacts 12 of relay 2 are opened, then switch 10 is turned off and contacts 11 of relay 1 are opened. The specified sequence of operation of elements of the device ensures arc-free switching on and off th circuit. The use of sensors for the end position of the relay improves the reliability and simplifies the device. 1 il. (L

Description

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The invention relates to electrical engineering, namely to devices for switching an electrical circuit of both constant and alternating current.

The purpose of the invention is to increase the reliability and simplification of the device.

The drawing is a schematic diagram of the device.

The device for arc-free switching of an electric circuit contains the first 1 and second 2 two-pole polarized relays with switching windings 3 and 4, and disconnecting 5 and 6, starting the winding 3 of the first relay and breaking winding 6 of the second relay 2 are connected to the corresponding enable inputs 7 and disconnecting 8, and the ends are connected to the control common input 9j, a power semiconductor switch 10, having one stable state, connected in series with the contact 11 of the first relay 1, and in parallel with the specified serial circuit The switch 12 of the second relay 2 is connected; the indicated parallel circuit is connected between the terminals 13 and 1A for connecting a switched circuit, a transistor switch 15 connected in parallel to the input of the galvanic isolating element 16, the output of which is connected between the control input of the power semiconductor switch 10 and the output 14 for connecting a switched circuit connected to the power semiconductor switch 10, and the input between the common control terminal 9 and through the current limiting resistor 17 to the output of the logic element OR 18, the first input of which o is connected to control disconnect input 8, first detector 19, responsive to switching on the first relay 1j located on its magnetic core (for example, at the pole) connected between control enable input 7 and the connection point of the second input of logic element 18 with the start of the switching winding 4 of the second relay 2, the second sensor 20, which reacts to the disconnection of the second relay 2 and located at the pole of its magnetic circuit, connected between the shutdown control input 8 and the connection point of the control input of the transistor switch 15 from the beginning Ohm breaking winding 5 of the first relay I.

The device works as follows.

When a pulse is applied to the control input 7, a current flows through the winding 3 of turning on the first relay G, which leads to switching it on and closing contact 11.

When the crust of the first relay 1 reaches its end position, the first sensor 19 is triggered, which causes current to flow through the winding 4 of the second relay 2, as well as through the logic element 18, the current limiting resistor 17 and the input circuit of the galvanic isolation element 16, which leads to the activation of power semiconductor key 10 and the second relay 2, the closure of the contact 2, Since the speed of the power semiconductor key 10 is significantly higher than the speed of the relay, the closure of the contact 12 of the second relay 2 occurs on chennom polzgarovodnikovom the power key 10, thereby making bezdugovoe electrical circuit. When the control pulse is removed from the switch-on input 7, the power semiconductor switch 10, having one steady state, is switched off.

When a control pulse is applied to the shut-off control input 8, current flows through the winding. 6 disconnecting the second relay 2, as well as through the logic element 18, the current limiting resistor I7 and the input circuit of the galvanic isolation element 16, which turns the power semiconductor switch 10 on, disconnecting the second relay 2, and opening the contact 12. At the same time, when contact 12 is opened, the power semiconductor switch 10 is in the on state, because its speed is much higher than the speed of the relay, resulting in an arcless opening of contact 12.

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When the second relay 2 reaches its final position, the second sensor 20 triggers, providing a tripping impulse that causes current to flow through the disconnecting coil 5 of the first relay 1 and through the control input of the transistor switch 15. This turns on the transistor switch 15 that shunts

galvanic isolation element 16, and turning off the power semiconductor switch 10, as well as disconnecting the first relay 1, opening contact II. Since the speed of the transistor switch 15 is much higher than the speed of the relay, opening the contact 11 of the first relay 1 occurs when the power semiconductor switch 10 is turned off. When removing the control pulse from the disconnect input 8, the switch transistor 15 turns off and the switching device takes the initial state.

Thus, just as when switching on the electric circuit, arc-free disconnection of contacts 1 G and 12, respectively, of the first 1 and second 2 polarized two-stable relays is provided.

The use of the proposed technical solution allows us to simplify the device by eliminating the multi-element control unit and to increase reliability by using sensors and eliminating switching capacitors that have sufficient

a transistor switch and an element of galvanic isolation, with the beginning of the on and off windings of these relays are connected, respectively, to the control inputs of the on and off, and the ends of the windings of the on and off are connected to the common control input, power semiconductor key and contacts the first polarized relay form a series circuit in parallel of which the contact of the second polarized relay is connected, the first input of the galvanic isolation element is connected to the common control the input and the output of the galvanic isolation element to the input of the specified power semiconductor key, the input of the transistor switch is connected parallel to the input of the galvanic isolation element, characterized in that, in order to increase the reliability and simplify the device, a logical element OR is inserted into it sensor of the end position of the relay core, the first sensor being located on the magnetic wire of the first polarized relay

large capacity and operating voltage, ZO and the second sensor - on the magnetic core

consequently, the considerable size, which impede the implementation of the device in the iniatic version.

 These advantages allow the use of a predictable device for

arc-free electrical circuit switching in autonomous automation systems installed on mobile installations and aircraft devices.

Claims (1)

Invention Formula Device for arc-free switching of an electrical circuit, containing the first and second two-stable polarized relays, a power semiconductor key with one abutment the second polarized relay, the inputs of the logical element SH are connected to the control inputs of the enable and disable, and the output of the logic element OR is connected to the second input of the galvanic isolation element through the current-limiting resistor, the first sensor is included in the dissection of the circuit between the connection points of the windings switch on polarized relays to the enable control input, the opening winding of the first polarized relay is connected to the control input ry of the opening input via the second sensor, and The input of the transistor switch is connected to the beginning of the winding of disconnecting the first polarized relay.