Patent ID: 7511974
Filing Date: 2009-03-31
Classification: H02M

Abstract:
1. A high voltage charging circuit, for charging a high voltage capacitor, comprising: a DC source for outputting a large current at a low voltage level; a transformer for receiving the large current at the low voltage level and then performing an energy conversion to output a small current at a high voltage level; a diode receiving the small current at the high voltage level, the diode then outputting the small current to the high voltage capacitor to charge the high voltage capacitor; a power transistor, a turn-on control circuit for controlling a turn-on time of the power transistor; a turn-off control circuit for controlling a turn-off time of the power transistor, wherein the power transistor is turned off by the turn-off control circuit when the energy of the transformer is released to a threshold; and a standby detection circuit for stopping switching the power transistor when the voltage of the high voltage capacitor is greater than a predetermined voltage, wherein the standby detection circuit further comprises: