| 摘要 |
PURPOSE:To improve the efficiency by providing a timing circuit giving a time constant to an on-level change of a base voltage of a forward bias transistor (TR) so as to reduce the loss when the switching semiconductor element is turned on. CONSTITUTION:The timing circuit 10 is provided between an output terminal of an inverter 5 and an input terminal of an inverter 6. Further, the timing circuit 10 consists of a diode D2 for discharge connected in parallel with a time constant resistor R7 inserted between an output terminal of the inverter 5 and an input terminal of the inverter 6 and of a capacitor C2 for time constant provided between an input terminal of the inverter 6 and a connection point beta. In turning on the forward bias TR 2 to provide a forward bias to a switching semiconductor element 8, a reverse TR 3 is turned off by the level change in the control signal and the forward bias TR 2 is turned on with a delay by a time set by the time constant of the timing circuit from the level change of the control signal. |
