Velocity feedback circuit for variable frequency control device of alternating current motor and method therefor

Abstract

The invention discloses an AC motor speed feedback circuit with AC frequency conversion controller as single chip machine, which comprises the following parts: speed-measuring unit, receiving circuit, separating circuit, output circuit and single chip machine, wherein the speed-measuring unit generates period and speed-measuring signal in relative with AC motor rotary speed, which outputs the signal; the receiving circuit receives speed detecting signal of speed-measuring element, which transmits the signal into fitful electric parameter; the separating circuit receives the transmitted speed measuring signal from receiving circuit, which outputs electric separating signal; the output circuit receives speed-measuring signal separated by circuit separation, which transmits the measuring signal into pulse signal to output to single-chip machine output end; the single-chip machine receives speed measuring signal and accumulates the signal, which adjusts driving power frequency and voltage of AC motor.

Description

technical field [0001] The invention relates to a speed feedback circuit of an AC variable frequency controller of a motor, in particular to a speed feedback circuit of an AC variable frequency controller of a motor using a single-chip microcomputer as a control device, and a speed feedback method for the circuit. Background technique [0002] With the improvement of energy-saving and intelligent requirements for household appliances, AC frequency conversion technology has been widely used in the field of household appliances. The function of AC frequency conversion technology is to adjust the speed of the motor by AC frequency modulation, so as to meet different speed requirements, and at the same time, it can avoid the empty energy consumption of the motor and achieve the purpose of saving electricity. [0003] The widespread use of AC frequency conversion technology is determined by its own advantages. This needs to be explained from the principle of motor speed regulati...

AI Technical Summary

Problems solved by technology

This situation causes the slip rate of the motor to increase sharply, which in turn causes the current through the motor coil to increase sharply compared with the normal operation of the motor, which seriously damages or even burns the motor.

[0027] Similarly, the above-mentioned frequency conversion controller with a single-chip microcomputer as the core control device cannot adjust the output in time according to the actual speed of the motor, and accurately control the speed of the motor.

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