Control circuit for driving relay to be quickly switched on and off

Abstract

A control circuit for driving a relay to be rapidly switched on and off comprises a relay, a first node of a coil of the relay is connected with a power supply through a boosted circuit, a second nodeof the coil of the relay receives a relay driving signal through a switch control circuit, and the boosted circuit comprises a PNP type triode, a first resistor, a second resistor, an energy storagecapacitor and a first diode. An emitter of the PNP type triode and the anode of the first diode are connected with a power supply, the base of the PNP type triode is connected with the power supply through the first resistor, the collector of the PNP type triode and the cathode of the energy storage capacitor are grounded through the third resistor, and the cathode of the first diode and the anodeof the energy storage capacitor are connected with the first node of the coil of the relay. The switch control circuit comprises an NPN type triode and a fourth resistor, the base electrode of the PNP type triode is connected with the collector electrode of the NPN type triode and the second node of the coil of the relay through the second resistor and a voltage stabilizing tube, the base electrode of the NPN type triode receives relay driving signals through the fourth resistor, and the emitting electrode of the NPN type triode is grounded.

Description

technical field [0001] The invention relates to the technical field of drive control of relays, in particular to a control circuit for driving relays to switch on and off quickly. Background technique [0002] Relays play an important role in our daily life and in all walks of life, such as plug-in card power-taking switches in life, touch doorbells, and drive of screen doors in rail transit, low-voltage and small-current control of high-voltage and large-scale power equipment. Current, frequency converter and pre-charge protection of active power filter circuit, etc. The relay is composed of a coil and a contact, and has two working states of on and off. When the relay is turned on, a higher voltage is required to provide sufficient energy for the contact to pull in during the process of contact pull-in, and the contact pull-in Only a lower voltage is required to keep the contacts in the closed state after closing. If in order to ensure the reliable opening of the relay, t...

AI Technical Summary

Problems solved by technology

When the relay is not working, the high driving voltage VH charges the energy storage capacitor C4 to ensure sufficient voltage to drive the contacts of the relay to pull in; after the relay pulls in, the high driving voltage VH stops driving the relay under the action of the current limiting resistor R8 , continue to supply power to the relay from the low driving voltage VL, thereby reducing the heat generation of the relay coil, but this method requires dual power supply, which has higher requirements for power supply

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