Control device for switching on and switching off relay and air conditioner

Abstract

The invention discloses a control device for switching on and switching off a relay and an air conditioner. The control device for switching on and switching off the relay comprises a control unit, a power supply and a relay, wherein the power supply is electrically connected with the relay; a zero-cross detection circuit is connected in parallel between the power supply and the relay and is used for detecting a zero-cross signal of the power supply and transmitting the zero-cross signal to the control unit; the control unit is connected with the signal input end of the relay and is used for switching on or switching off the relay according to the zero-cross signal. According to the control device for switching on and switching off the relay, the zero-cross signal is detected; the relay matched with inductive load is controlled when the power supply cross the zero point, so that the peak voltage generated when the relay is switched on and off can be greatly reduced; meanwhile, according to the control device, a resistance-capacitance absorbing circuit can also be omitted; the miniaturization of a computer board can be facilitated; the cost can be lowered.

Description

technical field [0001] The invention relates to the field of relay control, in particular to a relay closing and opening control device and an air conditioner. Background technique [0002] The loads controlled by the air conditioner computer board in the prior art can generally be divided into two types, inductive loads and resistive loads; the main types of resistive loads are heating belts; the main types of inductive loads are solenoid valves, AC contactors, and AC fans. [0003] Generally, low-voltage relays control strong inductive loads, but peak voltages will be generated during the pull-in and disconnection of the relays. In order to reduce the peak voltage values, resistance-capacitance absorption circuits are generally used for matching. The usual practice is to assemble resistors on the computer board. The capacitive absorption circuit reduces the peak voltage when the relay is closed and disconnected, and improves the reliability of the relay. Specific control ...

AI Technical Summary

Problems solved by technology

[0005] Since the resistance-capacitance circuit is added at both ends of the load, considering the creepage distance and other factors, the resistance-capacitance circuit takes up more space on the computer board. At present, the development direction of the air conditioning unit is miniaturization, convenient installation, and the development of miniaturization of the unit. It is doomed to require the size of the electronic control box to be reduced, so the size of the computer board must be reduced; however, due to the existence of the resistance-capacitance circuit, the miniaturization of the computer board is hindered.

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