Patent ID: 6982882
Filing Date: 2006-01-03
Classification: H02M

Abstract:
1. A high voltage charging circuit for charging a high voltage capacitor, comprising: a direct current power source for outputting a large current with a low voltage value; a transformer for transforming the large current with a low voltage value into a small current with a high voltage value for output; a diode for inputting the small current with a high voltage value and then outputting the small current with a high voltage value to the high voltage capacitor to charge the high voltage capacitor; a power transistor; wherein when the power transistor is turned on, the transformer transforms the large current with a low voltage value but does not output the large current with a low voltage value; when the power transistor is turned off, the transformer stops transforming the large current with a low voltage value and outputs the large current with a low voltage value; an activation control circuit for controlling an ON time period of the power transistor; and an inactivation control circuit for controlling an OFF time period of the power transistor; wherein the activation control circuit and the inactivation control circuit control the ON time period or the OFF time period of the power transistor by controlling a positive output signal from a positive end of a flip flop.