Zero cross detection circuit of alternating current power supply

Abstract

The invention discloses a zero-crossing detection circuit of an alternating current power supply, which belongs to the technical field of alternating current zero-crossing detection, and comprises a full-bridge rectifier module, a photoelectric coupler, a first resistor, a Zener diode and a zero-crossing output end, the photoelectric coupler comprises a light emitting diode and a phototriode, the full-bridge rectifier module processes an alternating current input signal into a half wave, and the first resistor is connected with the Zener diode; and the current-limiting resistor and the Zener diode are sequentially connected in series to the two ends of the light-emitting diode. On the premise that active devices such as a comparator are not used, zero-crossing signal detection of an alternating-current power supply in an extremely wide range is achieved through simplest and common discrete components, a zero-crossing detection circuit is greatly simplified, cost is reduced, isolation of input signals and output signals is achieved, and the circuit has good anti-jitter capacity and is worthy of being used and popularized.

Description

technical field [0001] The invention relates to the technical field of AC zero-crossing detection, in particular to a zero-crossing detection circuit of an AC power supply. Background technique [0002] The current zero-crossing detection circuit has problems such as high complexity of the detection circuit, poor anti-stability of the output signal, and narrow range of AC voltage. [0003] Some existing zero-crossing detection circuits need to use a comparator, so the comparator must be supplied with power at the AC detection end, and the cost and circuit complexity are very high. There are also some zero-crossing detection circuits with higher complexity and more devices used. In addition, some zero-crossing detection circuits can only be used for zero-crossing detection of mains power. For this reason, a zero-crossing detection circuit of an AC power supply is proposed. Contents of the invention [0004] The technical problem to be solved by the present invention is: ...

AI Technical Summary

Problems solved by technology

[0002] The current zero-crossing detection circuit has problems such as high detection circuit complexity, poor anti-stability of the output signal, and narrow range of AC voltage.

[0003] Some existing zero-crossing detection circuits need to use a comparator, so the comparator must be supplied with power at the AC detection end, and the cost and circuit complexity are very high

There are also some zero-crossing detection circuits with high complexity and more devices used.

In addition, some zero-crossing detection circuits can only be used for zero-crossing detection of mains power.

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