Patent ID: 8988908
Filing Date: 2015-03-24
Classification: H02H,H02M

Abstract:
1. A power supply circuit, comprising: a first resistive element in series between a first terminal of a power switch and a mid-point between a first pair of series-connected rectifying elements; a DC/DC converter connected at the terminals of the first pair for providing a DC voltage; a triac in parallel with the first resistive element; a control circuit adapted to control the triac, the control circuit including an element setting a threshold voltage above which the triac is controlled to conduct during a steady-state operation of the power supply circuit, and below which the triac is controlled not to conduct during a power-on operation of the power supply circuit, wherein the control circuit is connected to the triac and an AC power terminal; and at least one zener diode connected between the AC power terminal and the mid-point between the first pair of series-connected rectifying elements.