| 摘要 |
PURPOSE:To obtain a stable and excellently accurate DC output from a switching power source device by suitably selecting the relationship between the number of turns of a transformer and a DC output voltage. CONSTITUTION:A serial circuit is constituted by a DC power source 7, a primary winding L1, and a transistor Q1. The terminal 10 of a secondary winding L2 is connected through a rectifying diode D2 and a smoothing circuit 6 to an output terminal. The output terminal 9 is connected to the base of a transistor Q1 via an error amplifier 1 and a control circuit 2. A terminal 11 is connected through a rectifying diode D1 to the collector of a transistor Q3, and an emitter is connected through a smoothing circuit 5 to an output terminal 8. The output terminal 8 is connected to the base of a transistor Q3 via an error amplifier 3 and a control circuit 4. The numbers N21 and N22 of turns at the terminals 10 and 11 of the secondary winding L2 and DC output voltages V21 and V22 obtained at the output terminals 9 and 8 are in the relationship of N22/V22>N21/V21. |
