| 摘要 |
PURPOSE:To alleviate a base drive power and to improve the efficiency by connecting a capacitor through a switch with the base of a main transistor, and flowing a reverse bias current from the capacitor. CONSTITUTION:A current feedback drive type DC/DC converter turns ON and OFF a DC power source 7 via a main transistor (Tr) 9 through a main transformer 1 to smooth the secondary side output of the transformer 1, thereby obtaining a DC output. In this case, a reverse bias circuit and the quartic winding 23 of a drive transformer 8 are connected between the collector of the Tr 9 and the primary winding 20 of the transformer 8. Thus, a drive pulse is applied to the base of the Tr 9 through the tertiary winding 22 of the transformer 8 and the primary winding 20 by a drive pulse of a drive Tr 10 to turn ON it. Simultaneously, a DC voltage is obtained at a smoothing condenser 35, and a TR 30 is maintained in OFF state by the ON of the Tr 11. When the Tr 9 is turned OFF, the Tr 30 is turned ON by the OFF of the Tr 11, and the capacitor 35 applies a reverse bias voltage between the base and the emitter of the Tr 9. |
