| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a switching power source device that is able to improve efficiency in switching operation.SOLUTION: A switching power source device comprises: a voltage detecting section 2 that feeds back the voltage value of a secondary side DC voltage Vcc3 to a control section IC1; a switching operation command section 3 that outputs an on/off command on the basis of the magnitude relation between the voltage value of the secondary-side DC voltage Vcc3 and the minimum/maximum swing voltage value and, at the same time, outputs an on-command in a case where the load is in a normal operating state; a control section IC1 that controls the duty ratio of switching means Q1 and, also, performs/stops a switching operation according to the on/off command; and a blocking section 4 that blocks supply of voltage to the voltage detecting section 2 when load is in a standby state. When the supply of voltage to the voltage detecting section 2 is blocked by the blocking section 4, the voltage value fed back from the voltage detecting section 2 is made irrelevant to the actual voltage value of the secondary side DC voltage Vcc3.</p> |
