| 摘要 |
PURPOSE:To reduce the power loss at starting time and to simplify a power source circuit of a blocking oscillation type by charging a bias capacitor with part of a current when a turning OFF switching element is conducted in the power source circuit. CONSTITUTION:A power source in which a switching transistor TR1 is connected in series with the primary winding N1 of a converter transformer 2 and controlled by a blocking oscillation type, a capacitor C5 for applying a gate bias to a thyristor SC for supplying a charge to a transistor TR1 in a turning OFF capacitor C1 is charged with part of the charge of the capacitor C1 when the thyristor SC is conductor. Further, a control transistor TR2 controlled by output voltages V1, V2 is connected with the gate circuit of the thyristor SC. Thus, a current flowed to a starting resistor R4 can be reduced. |
