| 摘要 |
A switching power supply circuit (101) includes a first rectifier circuit (102) converting an alternate current to a direct current, a switching operator (20), a switching transformer (103) including a primary coil supplied with a switched current and a secondary coil inducing power corresponding to the current, a second rectifier circuit (30) rectifying the power induced by the secondary coil, and a control circuit (40) changing a ratio of a current flowing to a photocoupler (107) to an output voltage from the second rectifier circuit (30) in a standby mode and in a power-on mode to reduce a noise of the switching transformer in each of the modes. |
