| 摘要 |
PURPOSE:To prevent a delay in rise of a driving current of a switch element and to improve the responsiveness by providing a voltage adjustment means, and setting a DC constant voltage from a DC power supply higher than a voltage inputted in the operation of the said switching element. CONSTITUTION:When a switching transistor(TR) 8 is turned on, no base current Ib flows to a power TR 3 and is turned off. Since an output voltage Vb of a reference voltage circuit 9 reaches a high level, a DC constant voltage Vd of a constant voltage output circuit 11 is adjusted to a high level. On the other hand, just before a TR 3 is again turned on from the said state, the DC constant voltage Vd inputted to a MOSFET 6 is kept to a high level. That is, just after the operation of the power TR 3, the output voltage of the constant voltage output circuit 11 is kept high. Since the rise of the base current Ib is based on a high level, the time reaching the rise steady state is very rapid. |
