Patent ID: 6236578
Filing Date: 2001-05-22
Classification: H02M

Abstract:
A power supply for converting an inputted oscillating voltage into an outputted steady state voltage, the power supply comprising:a voltage converting circuit for converting the inputted oscillating voltage into a first steady state voltage;a transformer having an input end electrically connected to an output end of the voltage converting circuit for transforming the first steady state voltage into a second oscillating voltage, an output end and a control end for controlling on and off of the transformer;a pulse generator having an output end electrically connected to the control end of the transformer for generating a pulse signal so as to control the on and off of the transformer, and a control end for controlling a duty cycle of the pulse signal;a rectifying circuit having an input end electrically connected to the output end of the transformer for rectifying the second oscillating voltage to generate the outputted steady state voltage; anda feedback circuit having a first input end electrically connected to the output end of the rectifying circuit, a second input end electrically connected to a variable power source, and an output end electrically connected to the control end of the pulse generator;wherein the feedback circuit will control the duty cycle of the pulse signal generated by the pulse generator according to the outputted steady state voltage inputted from the first input end and an output voltage of the variable power source inputted from the second input end so that the outputted steady state voltage generated by the power supply can be controlled by the variable power source connected to the second input end of the feedback circuit.