Shanghai Natlinear Electronics Co., Ltd.

Chunda Wu

Dongfeng Wang

Hu Xia

Guizhi Liu

An AC detection circuit, including a live wire input end and a neutral wire input end; a first diode and a second diode being both Zener diodes and with anodes connected to each other; a first resistor and a second resistor; a rectification module connected to the live wire input end and the neutral wire input end; a power supply for supplying power; a current mirror module with a current value at the first output end and a current value at the second output end having a fixed ratio; a unidirectional conduction module, configured to enable unidirectional conduction of the current from the current mirror module to the first diode; and a current comparison module, including an oscillator, a timer, a current comparator and a reference current source, and configured to compare the current value of the second output end of the current mirror module with a reference current value.

Alternating-current detection circuit

An AC resistance detection circuit and system. The circuit includes: a working state control module, generating a working state control signal; a sampling module, outputting a sampling signal of a resistance between a neutral wire and a live wire in the detection state; a comparison module, receiving a reference signal and the sampling signal, and outputting a comparison result; a counting signal generation module, receiving an oscillation signal and the working state control signal, and outputting the oscillation signal as a counting signal in the detection state; a zero clearing module, receiving the comparison result and the working state control signal, and outputting an active zero clearing signal when resistance between the neutral wire and the live wire is greater than a threshold; and a counting module, connected to the counting signal and the zero clearing signal, and outputting a high level when a count value reaches a preset value.

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Shanghai, China

Chunda Wu