SU1582347A2 - Switching device - Google Patents

Abstract

The invention relates to a pulse technique and can be used to automatically switch contactors controlling the operation of a reversible motor. The purpose of the invention is to increase the reliability of work. The switching device contains windings 1, 4 contactors with contacts 2, 5, contacts 3, 6 limit switches, bus 7, 8 power supply, diode bridges 10, 17, 18, thyristors 11, 19, 20, threshold element 12, capacitor 13 and the resistor 14 is the master circuit time, the siren winding 16, resistors 21, 22, diodes 23, 27, 27, 28, storage capacitors 25, 26, control pins 29, 30. The introduction and connection of additional resistors 31, 32, diodes 33, 35 and capacitor 34 ensures that the thyristors 11, 19, 20 are kept in the on state at low current consumption of the windings 1.4. 1 il.

Description

The invention relates to a pulse technique and can be used to automatically switch contactors that control the operation of an AC reversible electric motor using control buttons and small power switches

The purpose of the invention is to increase the reliability of operation by ensuring that the thyristors are kept in the on state at low current consumption of the windings1,

The drawing shows a circuit diagram of a device about

The switching device contains the first output circuit of the first contactor winding 1 of the first contactor, the disconnecting contacts 2 of the second contactor and the disconnecting contacts 3 of the first limit switch, the second output circuit of the second contactor of the second contactor 4, disconnecting contact 5 of the first contactor and the breaking contacts B the second limit switch. The first. Outputs of the first to the second output circuits are connected to - the first terminal 7 of the mains supply, the second terminal 8 of which is connected to the first input terminal 9 of the first diode bridge 10, loaded with the first thyristor 11c. -threshold element 12 and the circuit of the capacitor 13 and the resistor 14 at the input. Between pin 9 and the second input terminal 15 of bridge 10, a siren winding 16 is turned on. Conclusion 15 is connected to the second terminals of the first and second output circuits via the input diagonals of the second and third diode bridges 17 and 13, which are loaded with second and third thyristors 19 and 20, respectively The first and second resistors 21 and 72 in the cathode circuits, resistors 21 and -22, through the first and second diodes 23 and, k, connect the first and second memory capacitors 25 and 26, which are connected to the diodes 27 and 28. the anodes of thyristors 19 and 20, the control electrodes of which are connected to pin 9 via the closing contacts 29 and 30 of the first and second control buttons.

Between the connection points of the winding terminals 1 and 4 with the terminals of contacts 2 and 5, respectively, the first one is turned on.

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additional resistor 31. The second additional resistor 32 is on. in series with the thyristor 11 and through the first additional diode 33 is connected to an additional storage capacitor 3, and a second additional diode 35 is connected counter-parallel to the series circuit from according to the included thyristor 11 and diode 33.

The device works as follows

In the initial state, when the supply voltage is applied, the thyristors 11, 19 and 20 are closed, windings 1 and k and winding of siren 16 are not excited. When the contacts 29 are closed through the limiting resistor of the thyristor 19, the resistor 21, one of the bridge diodes contacts 3 and 2 and the winding 1, a current comes in which causes the opening of the thyristor 1I. Through the winding of the siren 16, the bridge 17, the thyristor 19, the resistor 21, pins 3 and 2, the winding 1 and the winding k connected through the resistor 31 parallel to it, a current flows through the siren 16, signaling that the conveyor of the dispenser is turned on. Since when the magnetic system of the electromagnet of the contactor is open, the inductive resistance of its winding is small, then under the action of the current flowing through the siren winding 16 and winding 1, less than 20% of the nominal winding voltage drops on the latter. Under the influence of this voltage, the contactor cannot operate. The main part of the supply voltage falls on the winding of the siren 16, and it is: in the on state. To compensate for the decrease in the voltage on the winding of the siren 16 for the voltage drop on the winding 1 when the magnetic circuit is open, a capacitor 37 serves. Once the trigger 19 is opened along the control circuit, the voltage across the resistor 21 is charged through the diode 23 by the capacitor 25. Due to the fact that in the gaps between the pulses of the pulsating current, the capacitor 25 is de-energized through the diode 27 to the anode circuit of the thyristor 19, the latter is kept -opened

Under the action, the voltage on the winding included lilac; 1b through the diode bridge 10 and the resistor charged capacitor 13 to the voltage off

wounds of the threshold element 12. The current pulse of the capacitor 13 briefly unlocks the thyristor 11, which bypasses the diagonal of the diode bridge 10 through the resistor 32. Through the bridge 10, the thyristor 11, the resistor 32, the thyristor 19, the resistor 21, contacts 3 and 2 passes the current , exciting winding 1. A contactor with a winding 1 is activated and, by means of its power contacts, switches on the conveyor motor. The discharge time of the capacitor 13 to the thyristor control circuit 11 is 1–3 semiconductors of the supply voltage and is sufficient to unlock the thyristor 11, after which the thyristor 11 is kept open by discharging the capacitor through its anode circuit 3 in the pauses between pulses of pulsating current. After unlocking the thyristor 11 through the bridge 17 and the already open thyristor 19, the contactor with the winding 1 is held in the on position, and the winding of the siren 16 is shunted through the bridge 10 by the thyristor 11 and turns off. In this way, the contactless switching of the siren and the contactor is realized. The opening of the contacts 5 eliminates the simultaneous inclusion of the contactor with the winding A.

To reliably keep the thyristors 11 and 19 open by increasing the current flowing through their anode circuits, a resistor Z is used to reach the value that the thyristors hold current through the anode circuit, while most of the network voltage drops across the resistor 31 and the winding C is not excited.

When the working body of the conveyor moves to the preset position and opens the contacts 3, the thyristors 11 and 19 are turned off. The contactor with winding 1 opens its power contacts, the conveyor stops. For re

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It is necessary to close contacts 30. As described above, the key containing the diode bridge 18 and the thyristor 20 are turned on. The winding of the siren 1b is energized and the capacitor 13 begins to charge through the resistor 1 a sound signal is charged until the voltage of the threshold element 12 is triggered, the thyristor 11 is opened. After this, the siren coil 16 is shunted and the coil of the second contactor is energized, which turns the actuator on by reverse contacts The switching of the conveyor, and the contacts 2, excludes the simultaneous operation of the contactor with the winding 1. When the contacts 6 of the trip switch are opened, the supply circuit of the winding k and the thyristors 11 and 20 opens. Contactor with winding C is disconnected, stopping the conveyor. Further, the operation of the device is repeated.

Ph o o m l o l invention

Peyoyuchivayuschy device auth. St. No. 1 78317 characterized in that, in order to increase reliability, the operation additionally contains resistors, a storage capacitor and a diopes, with the first additional DCF connected between the connection points of the windings with the terminals of the Kci cycles of the first and second output circuits, The second additional resistor is connected in series with the first thyristor and connected to the additional capacitor through the first additional diode, and the second additional diode is connected anti-parallel to the series circuit from according to the switch. nnyh tioistora first diode and the first additive.

Claims (1)

The claims ed Switching device according to ed. St. Have 14783 17? characterized in that, in order to increase the reliability of operation, it additionally contains resistors, a storage capacitor and diodes, while the first ις „' - ¹ additional resistor is connected between the connection points. Of the windings with the terminals of the contacts of the first and second output circuits, the second additional resistor is connected in series with the first thyristor and connected to the additional capacitor through the first additional diode, an opposite 45 parallel parallel series circuit is connected to the second additional diode from according to the included first thyristor and first additional diode.