FLYBACK WITH SWITCHING FREQUENCY RESPONSIVE TO LOAD AND INPUT VOLTAGE

摘要

A power source constituted of: a power factor corrector controller; an electronically controlled switch responsive to the power factor corrector controller; a first inductor serially connected with the electronically controlled switch and arranged to pass a direct current there through when the electronically controlled switch is closed; a second inductor magnetically coupled to the first inductor and coupled to provide power to a load in a flyback arrangement; a third inductor magnetically coupled to the first inductor, a first end of the third inductor arranged to provide a representation of the voltage level of the direct current when the electronically controlled switch is closed, and to provide a representation of the voltage level of the power provided to the load when the electronically controlled switch is open; and an off time control circuit in communication with the power factor corrector controller and responsive to the third inductor representations.