Circuit for preventing powered on moment impact in frequency converting air conditioner

Abstract

The invention provides a circuit for preventing power up instantaneous shock in inverter air conditioner which includes a positive temperature coefficient thermistor series connected with AC electrical source front line in air conditioner system, a power relay switch parallel connected with two sides of the positive temperature coefficient thermistor, the power relay coil and a controllable switch device are series connected between electrical source and ground electrode, the controllable switch device control end is connected with one electrical source in air conditioner system. The circuit provided by the invention can prevent current shock in power up instantaneous, and can conquer disadvantage of poor anti-interference performance in present device because of impervious for main control singlechip reduction, and protect air conditioner system normal working more efficiently.

Description

technical field [0001] The invention relates to a control circuit of an inverter air conditioner, in particular to a circuit for preventing instant impact when power is turned on in the inverter air conditioner. Background technique [0002] In the control system of the air conditioner, when the AC power has a large impact at the moment of power-on, the current impact can exceed 50A. Such a large impact is very harmful to the electrolytic capacitor and the entire system. [0003] In order to prevent the impact of large current on the entire air-conditioning control system, PTC (Positive Temperature Coefficient Thermistor) is widely used in the field of air-conditioning control. PTC is a typical temperature-sensitive semiconductor resistor. When it exceeds a certain temperature (Curie temperature), its resistance value increases stepwise with the increase of temperature. However, the PTC does not act alone. The most widely used at present is to connect the PTC in series on t...

AI Technical Summary

Problems solved by technology

[0005] The above methods can basically prevent the impact of power-on, but the work of the single-chip microcomputer will be affected by the external environment. The reset of the single-chip microcomputer of the main control system, once the single-chip microcomputer 7 of the main control system is affected by external factors, the reset phenomenon occurs, the I / O port of the main control single-chip microcomputer becomes low level, and the control terminal of the controllable switch device Q1 has no high level signal input , the controllable switch device is disconnected, which will lead to the disconnection of the power relay. At this time, because the compressor control system 2 is still working normally, a large current will flow through the PTC resistor. Due to the characteristics of the PTC, when the temperature rises The resistance value will increase, which will cause PTC to heat up and form PTC protection, which will cause the problem that the electric control of the external machine does not work, thus affecting the normal operation of the entire air conditioning system

[0006] Therefore, as far as the effect of preventing the instantaneous impact of power on in the inverter air conditioner is concerned, the device can basically achieve the expected effect, but its shortcomings in anti-interference and stability are not satisfactory

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