Alternating current resistance detection circuit and system

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.