| 摘要 |
PROBLEM TO BE SOLVED: To provide a current resonance type power supply which is switched to a standby mode without receiving a standby signal from the outside.SOLUTION: The current resonance type power supply includes: a series circuit of a reactor Lr, a primary coil P and a capacitor C2; rectification and smoothing circuits D1, D2 and C3 by which a voltage of a secondary coil S is rectified and smoothed and a DC voltage is outputted; a control circuit 10 which alternately turns on and turns off switch elements Q1 and Q2; a voltage detection circuit 30 for detecting the DC voltage; a signal generation circuit PC which generates a feedback signal for turning on and turning off Q1 and Q2 on the basis of the detected DC voltage and outputs the feedback signal to the control circuit; load current detection circuits C4 and CCL for detecting a load current included in a resonance current that flows to the capacitor; a standby state detection circuit 11 for detecting the standby state on the basis of the detected load current and a standby threshold; and burst oscillation circuits 12, 13, CSB and 14 which generate a signal for a burst oscillation operation on the basis of the feedback signal when the standby state is detected.SELECTED DRAWING: Figure 1 |
