Zero-crossing detecting device and detecting method based on electromagnetic induction

Abstract

The invention provides a zero-crossing detecting device based on electromagnetic induction, comprising an alternating current power supply to provide an alternating current signal; an electromagneticinduction unit converting alternating current electrical signal into a low-voltage alternating current signal. The input end of the electromagnetic induction unit is arranged close to the alternatingcurrent power supply load wire;the output end of the electromagnetic induction unit is connected with the input end of the AC signal amplifying unit; the AC signal amplifying unit amplifies and outputs the positive half-wave signal of the low-voltage AC signal, and the output end is connected with the input end of the zero-crossing comparison unit; the zero-crossing comparison unit compares the amplified low-voltage AC signal with the zero-crossing detection signal, outputs a zero-crossing signal, and outputs the signal to the microprocessor; and the microprocessor determines the zero-crossingpoint of the AC signal based on the zero-crossing signal. The invention has the advantages of simple circuit and low cost, and does not need to isolate the output unit circuit, and only needs the electromagnetic induction unit and the zero-crossing comparison unit to realize the zero-crossing detection of the high-voltage AC power source, and can track the zero-cross point in real time when the load fluctuates sharply.

Description

technical field [0001] The invention belongs to the field of electronic technology, in particular to a zero-crossing detection device and detection method based on electromagnetic induction. Background technique [0002] At present, the development of smart home appliances is very rapid. The zero-crossing detection circuit is widely used in smart home appliance systems. Most of the existing zero-crossing detection circuits use resistor divider or voltage regulator to obtain the zero-crossing point. Although this method is easy to implement and low in cost, it is poor in electrical isolation and anti-interference ability; some zero-crossing The detection uses the RC method to take power from the grid, but the power consumption is large due to the continuous power consumption of the resistor during work; some directly connect the current-limiting resistor on the power line, directly drive the optocoupler device, and detect the zero-crossing signal. The structure is simple, a...

AI Technical Summary

Problems solved by technology

[0003] The technical problem solved by the present invention is to provide a zero-crossing detection device and detection method based on electromagnetic induction, which solves the problems of poor electrical isolation and anti-interference ability, high cost and high power consumption of the zero-crossing detection circuit in the prior art

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