Single-phase AC zero-crossing detection method

Abstract

The invention provides a single-phase AC zero crossing detection method. When a waveform is converted from a positive half cycle and when a zero position is passed, 100HZ and 50HZ pulsating waveformsare detected through a zero crossing detection sampling method or a peak value taking method by multiple times of sampling, and through micro control chip judgment, a voltage zero point is detected. The single-phase AC zero crossing detection method has the beneficial effects that the 100HZ and 50HZ pulsating waveforms are detected through the zero crossing detection sampling method or the peak value taking method by multiple times of sampling through micro control chip judgment, the purposes that the voltage zero point time is detected, zero crossing pulse signals are provided for the micro control chip, the zero crossing voltage of the pulsating DC signals can be accurately and effectively detected and calculated, and the control system adjusts the power, the rotation speed or the frequency of the motor can be achieved, the voltage errors are small, the synchronous reliability is high, and accuracy and safety are achieved.

Description

technical field [0001] The invention relates to a detection method, in particular to a single-phase alternating current zero-crossing detection method. Background technique [0002] At present, most of the single-phase AC zero-crossing detection circuits divide the voltage from the two-phase line (L or N) through resistors. When the waveform is converted from the positive half cycle to the negative half cycle, a pulsating signal voltage is taken out when it passes through the zero position. [0003] Using a single-phase AC zero-crossing detection circuit to realize the method of dividing the voltage from the two-phase line (L or N) through resistance, the circuit is single, the voltage error of the detection pulse signal is large, the synchronization reliability is poor, and there is a poor end where the zero-crossing point is ahead. The effect is also very unsatisfactory, and the motor speed and frequency of the electric control system and the frequency conversion control s...

AI Technical Summary

Problems solved by technology

[0003] Using a single-phase AC zero-crossing detection circuit to realize the method of dividing the voltage from the two-phase line (L or N) through resistance, the circuit is single, the voltage error of the detection pulse signal is large, the synchronization reliability is poor, and there is a poor end where the zero-crossing point is ahead. The effect is also very unsatisfactory, and the motor speed and frequency of the electric control system and frequency conversion control system cannot be guaranteed

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