| 摘要 |
PROBLEM TO BE SOLVED: To reduce vibration sound generated from a transformer during light-load operation in a switching power supply without increasing the size of the transformer and loss due to switching.SOLUTION: A power-supply device includes: a transformer 104 insulating a primary side and a secondary side; a switching element 108 provided on the primary side of the transformer 104 and turning on and off the supply of power to the transformer 104; and a switching control IC 110 outputting a pulse wave to the switching element 108 and controlling the switching operation turning on and off for outputting predetermined power from the secondary side of the transformed 104. The switching control IC 110 includes an off-time control circuit 200 that is a power-supply device capable of controlling burst operation and causes the switching control IC 100 to continuously output even numbers of pulses at a shorter period than a period halting the switching operation during a period performing the switching operation at the time of the burst operation. |
