Patent ID: 9179523
Filing Date: 2015-11-03
Classification: H02M,H05B,Y02B

Abstract:
1. A controller, comprising: a transformer; a control circuit having a bias voltage input, the control circuit activating when voltage applied to the bias voltage input reaches a threshold, the transformer having feedback output to the bias voltage input; a bias voltage circuit applying start-up bias voltage to the bias voltage input, the bias voltage circuit having: a resonant circuit providing a resonant current, a bias capacitor charged by the resonant current, wherein voltage on the bias capacitor is the start-up bias voltage applied to the bias voltage input, and a cutoff, comprising at least one diode, to shut down the resonant current when the transformer feedback output is above the threshold; wherein: the resonant circuit includes a voltage divider that divides a supply voltage to produce a divided voltage for the resonant current; and the voltage divider is adjusted so that when the transformer feedback output is above the threshold, voltage on the transformer feedback output is above the divided voltage, thereby turning off the at least one diode.