Residual Current Circuit Implemented in Complementary Metal Oxide Semiconductor for Remanence Correction

This research paper presented a design that will address the challenges brought by remanence in ground-fault current interrupter devices (gfci). Remanence or residual magnetism is the magnetization left behind in a ferromagnetic material (such as iron) after an external magnetic field is removed. Remanence will make the gfci devices less accurate and less reliable in tripping the current above threshold in just five (5) years. It affects the performance of the device in terms of efficiency, accuracy, and response time. In this research, the problems caused by remanence were alleviated by using two identical transformers in detecting residual current both for hot and neutral wires. The difference of the current detected by the two transformers will be the basis of the signal threshold in tripping the device. By doing so, the problems caused by remanence phenomenon will be solved without compromising the response time of the circuit which is around 16 mS. The design will extend the life span of GFCI devices up to 15 years.