Relay driving circuit and power equipment using same

Abstract

The invention relates to a relay driving circuit and power equipment using the same. The relay driving circuit is connected with a relay to be driven, and comprises a voltage stabilizing tube, a diode, a PWM driving signal output module and a switch tube, the voltage stabilizing tube and the diode are connected in series and then reversely connected to the two ends of a coil of the relay in parallel, the input end of the coil of the relay is connected with a power source, the output end of the coil of the relay is grounded through the switch tube, and the PWM driving signal output module is connected with the control end of the switch tube. The relay driving circuit further comprises a voltage-regulator tube control module which is used for short-circuiting the voltage-regulator tube whenthe relay is closed and kept closed and opening the circuit to enable the voltage-regulator tube to work when the relay is disconnected, and the voltage-regulator tube control module is connected to the two ends of the voltage-regulator tube. The power equipment comprises a relay and the relay driving circuit. The power equipment is an inverter, a PCS or a UPS. According to the invention, the turn-off speed of the relay can be greatly improved, the additional loss caused by quick turn-off of the circuit is very low, and the efficiency is improved.

Description

technical field [0001] The invention belongs to the field of control drive circuits and power electronic equipment, and in particular relates to a drive circuit for relays and power equipment using the drive circuit. Background technique [0002] The working principle of the relay generally requires a rated current to magnetize the coil during pull-in and provide the energy for pull-in; when the pull-in is completed, the coil has been magnetized, and only a small current is needed to maintain the relay in the pull-in state. Relays are widely used in power equipment. For example, in photovoltaic inverters, the on / off switching between the inverter output and the grid is generally controlled by relays. The speed at which the relays are turned on and off affects the switching time. [0003] At present, a commonly used relay drive circuit such as figure 1 As shown, dual power supplies are required in the drive circuit, and a large-capacity electrolytic capacitor needs to be sel...

AI Technical Summary

Problems solved by technology

[0005] 1. The normal shutdown speed of the relay is relatively slow, which cannot meet the application scenarios that require fast shutdown;

[0006] 2. In the conventional accelerated shutdown circuit, passive devices such as RC or regulator tubes are added, resulting in greater loss of the circuit when the relay is normally maintained.

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