Patent attributes
A control circuit of Ground Fault Circuit Interrupter (GFCI), includes a load connection circuit used to connect power end and load end while transferring AC thereof, a creepage detection circuit, a trip control circuit and a trip circuit, and further includes a self-diagnosis current generation circuit, a self-diagnosis display circuit and a first switch duct. When the input AC in positive half-cycle, one of the said trip circuit and the self-diagnosis display circuit is electrically connected, while another should be electrically connected while the input AC in negative half-cycle, so without manpower-provided simulated signal, the control circuit of GFCI can be self diagnosed of creepage protection function, for the feedback of the stand or fall circs in time.