Patent ID: 7235899
Filing Date: 2007-06-26
Classification: H02J,H02M,H05B

Abstract:
1. A switching constant-current power supply system including: a switching-type first power converter circuit operable, in response to supply of power from an external power source, to generate a stable DC voltage; a second power converter circuit capable of functioning as a DC-AC converter and operable, in response to supply of said DC voltage, to supply an AC or pulsed current to a load; a current detector circuit for generating a first feedback signal in proportion to a load current; a control circuit for controlling the operation of said first power converter circuit according to said first feedback signal so as to stabilize said load current; and a feedback circuit provided between said current detector circuit and said control circuit, said feedback circuit including a signal hold section for holding a signal, said feedback circuit being operable to supply the first feedback signal to the control circuit when the load current flows and to supply a second feedback signal to the control circuit when the load current does not flow, wherein said second feedback signal has a signal value approximately equal to that of said first feedback signal at a certain time point.