US 11,668,762 B2
Leakage current detection circuit, method and leakage current detector
Jianhua Lei, Shenzhen (CN); Yongbo Zhang, Shenzhen (CN); Hui Ma, Shenzhen (CN); and Geng Qin, Shenzhen (CN)
Assigned to SHENZHEN POWEROAK NEWENER CO., LTD, Shenzhen (CN)
Filed by SHENZHEN POWEROAK NEWENER CO., LTD, Shenzhen (CN)
Filed on Sep. 14, 2022, as Appl. No. 17/944,396.
Application 17/944,396 is a continuation of application No. PCT/CN2022/081474, filed on Mar. 17, 2022.
Claims priority of application No. 202111312286.3 (CN), filed on Nov. 8, 2021.
Prior Publication US 2023/0141539 A1, May 11, 2023
Int. Cl. G01R 31/52 (2020.01)
CPC G01R 31/52 (2020.01) 13 Claims
OG exemplary drawing
 
1. 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.