Patent ID: 6094365
Filing Date: 2000-07-25
Classification: H02H,H02M,Y10S

Abstract:
A power supply device of a switching mode, said device comprising:a transformer provided with a primary winding and at least one secondary winding, said primary winding having a first end and a second end;a direct current power supply circuit connected at an output end thereof with said first end of said primary winding;a switching element having a first end, a second end, and a control end, with said first end being connected with said second end of said primary winding, and with said second end of said switching element being connected with a ground, for opening and closing a primary current that flows through said primary winding;a control circuit connected at an output end thereof with said control end of said switching element for providing said switching element with a driving signal;a direct current output circuit connected at an input end thereof with an output end of said primary winding such that an output end of said direct current output circuit delivers a direct current voltage;a leakage current detection circuit connected at an input end thereof with a secondary side ground end of said transformer, and at an output end thereof with a primary side ground end of said transformer, for forming a current loop and transmitting a leakage current signal at the time when a leakage current takes place; anda leakage current protection circuit coupled with said detection circuit such that said protection circuit is separated from said detection circuit, and that said protection circuit is controlled by said leakage current signal of said detection circuit, and further that an output end of said protection circuit is connected with a work signal end of said control circuit, and further that said work signal input end of said control circuit is caused by said protection circuit to become connected with the ground at the time when said leakage current signal is transmitted by said detection circuit.