Leakage current detection circuit, method and leakage current detector

A leakage current detection circuit for detecting a leakage current of a device to be detected, wherein the leakage current detection circuit comprises a main winding, an auxiliary winding, a detection module, and a signal output module;

• wherein the main winding is used for being connected to a leakage current detection end of the device to be detected, the main winding is coupled to the auxiliary winding, and the auxiliary winding is respectively connected to the signal output module and the detection module;
• the signal output module is used for outputting pulse signals with positive and negative alternations so that the auxiliary winding is in a near-saturation state;
• and
• the detection module is used for detecting a current signal of the auxiliary winding which is in the near-saturation state, and detecting a leakage current of the device to be detected according to the current signal;
• wherein the step of detecting a leakage current of the device to be detected according to the current signal comprises:
• determining whether the current signal is greater than a preset threshold value;
• in response to the current signal greater than the preset threshold value, acquiring direction information about the current signal,
• reversely adjusting a size of a duty ratio of the pulse signal according to the direction information,
• reacquiring a current signal of the auxiliary winding;
• and
• obtaining the leakage current information according to the reacquired current signal and the adjusted size of the duty ratio, so that the leakage current of the device to be detected is detected