| 摘要 |
PROBLEM TO BE SOLVED: To reduce power consumption by maintaining an intermittent operation mode in a standby state, and to quickly switch an operation mode to a continuous operation mode in an operation state.SOLUTION: A switching power supply includes a full wave rectifier 14, a switching part 16, a power supply IC 18, a transformer 20, a rectification part 24, a constant voltage control part 28, and a switching signal generation part 32. The power supply IC 18 compares a mode switching voltage to be varied in accordance with secondary side power of the transformer 20 with a threshold and controls the switching part 16 by switching the operation mode between the intermittent operation mode and the continuous operation mode in accordance with the comparison result. The operation mode is switched to the continuous operation mode in a normal operation state by changing either one of the mode switching voltage and the threshold in accordance with a switching signal from the switching signal generation part 32. |
