SU1372407A1 - Device for activating electromagnetic relay - Google Patents

Abstract

The invention relates to electrical engineering and may find application in switching circuits of electromagnetic relays, contactors. The aim of the invention is to save energy. When the power is turned on through the winding 1 of the relay, an initial connection current flows. The initial bias current flows through the diode 8 from the additional power source formed by the zener diode 7 and the resistor 6. When the contact and the control key are switched, the starting current flows through the winding 1. When the capacitor is charged, a holding current from the auxiliary power source flows through the winding 1. 1 il.

Description

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The invention relates to electrical engineering and may find application in switching circuits of electromagnetic relays, contactors.

The aim of the invention is to save energy.

The drawing is a schematic diagram of a device for turning on an electromagnetic relay.

The device contains a winding 1 relay, one output of which is connected to one output 2 for connecting the main power supply directly, the other output to another output 3 for connecting the main power supply via serially connected control key 4 and capacitor 5, and to the additional power supply formed a resistor 6 and a zener diode 7, through a diode 8 having a polarity opposite to HomeHtno to the main power source. The relay is equipped with a disconnecting contact 9, one output of which is connected to another output 3 for connecting the main power source, the other output to the resistor 6 of the additional power supply directly, and to the connection point of the control switch 4 and capacitor 5 via an additional diode 10, having a polarity inverse to the main power source. The control switch 4 is complete with the switching pair, and its opening part through the resistor 11 bridges the capacitor 5.

The device works as follows.

When the device is disconnected from the main power source, the voltage on its elements is absent, the capacitor is discharged. When power is applied to outputs 2 and 3, the voltage is supplied through the disconnecting contact 9 of the relay to the additional power supply (resistor 6 and the zener diode 7), and from its output through the diode 8 to the winding 1 of the relay, and the bias current is flowing through the latter neither The parameters of the additional power source are chosen so that the magnitude of the initial bias current of the relay is less than the operating current and more than the relay return current, taking into account the supply voltage fluctuations within acceptable limits, i.e. so that the relay does not operate when the supply voltage increases by the permissible value and does not return spontaneously to its original state (after it has been turned on) while the supply voltage decreases by the permissible value.

At the moment of switching the control key 4, the voltage of the main power source is applied to the winding 1 of the relay, a starting current flowing through it equal to the relay operating current, and the capacitor 5 is selected so that its charge time reaches the value when the current through the winding 1 of the relay becomes equal to the return current of the relay, longer than the response time of the relay. When the control switch 4 is switched, the current in the winding 1 of the relay increases to the value of the relay operation current not from zero, but from a certain initial value, which contributes to reducing the transient time and accelerating the relay "Relay operation and opens its contact 9. After capacitor charge 5 to a voltage equal to the voltage drop across the resistor 6 of the additional power source (the voltage drop across the diodes 8 and 10 is neglected), the current through the winding 1 of the relay from the main power source stops. In the established mode, the relay holding current from the auxiliary power source flows through the winding 1 of the relay, the voltage to which from the main power source flows through the closing part of the control switch 4 and the auxiliary diode 10.

When the control key 4 returns to the initial position, the winding 1 of the relay and the auxiliary power source are disconnected from the main power source, the current through the winding 1 of the relay stops and the relay returns to the initial state. The capacitor 5 is discharged through the resistor 6 through the diode 10 circuit - the resistor 6 - diode B and through the resistor 11 across the circuit of the disconnecting part of the control switch 4 - the resistor 11. When the relay returns to its initial state, its 9 pin closes and voltage is applied from the main power source to the additional power source. In this case, the additional diode 10 is closed and the discharge of the capacitor 5 occurs through the resistor 11. The voltage from the output of the source of the additional

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power through diode 8 is fed to the winding 1 of the relay, the device is ready for the next switching on. The resistor 11 is selected so that the time for the full discharge of the capacitor 5 is shorter than the time interval between the moment the relay is turned off and the moment it is next turned on, i.e. to ensure the full discharge of capacitor 5 before the next switching on of the relay.

Thus, the proposed device makes it possible to save energy when the relay is on in a steady state, because the auxiliary power source is used before turning on the relay to create an initial bias current, and in steady state to provide a relay holding current.

Claims (1)

The invention includes a device for switching on an electromagnetic relay, comprising terminals for connecting a relay winding, a zener diode, a diode, a capacitor, two resistors, a control switch with a closing contact, and terminals for connecting neither a DC power supply, one of the terminals for connecting the relay coil is connected via a series-connected capacitor and the closing contact of the control key to one of the terminals for connecting the power source and through a diode to the connection point of the first resistor and Zener diode, another terminal for connecting the relay winding is connected to another output of the power supply and a zener diode, characterized in that, in order to save electricity, a second diode and terminals are connected to it A relay contact, a control switch is provided with a break contact, the first resistor is connected to one of the outputs for connecting the relay break contact, the other output is connected to one output for connecting the power supply and a diode to the capacitor and the closing contact of the control switch, the second resistor The control break contact is connected in parallel to the capacitor.