Capacitive power supply with surge current limitation

摘要

A capacitive power supply including: a first capacitive element and a first resistive element in series between a first terminal of a power switch and at least one rectifying element having a second terminal connected to a first electrode of at least one second capacitive element for providing a D.C. voltage; and a bidirectional switch in parallel on the resistor.

主权项

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.