| 摘要 |
PURPOSE:To rise a threshold voltage between a gate and a source with a small current and in a short period by previously charging a capacity formed in parallel between the gate and the source of a switching element having MOS type gate structure by means of a driving voltage lower than the threshold voltage between the gate and the source. CONSTITUTION:Driving voltage sources 8 and 9 are connected between the gate G and the source S of the switching element 1. The driving voltage powers 8 and 9 consist of transistors 3 and DC power source 2. The DC power source 2 of the driving voltage power source 8 has the voltage lower than the threshold between the gate G and the source S of the switching element 1, and the DC power source 2 of the driving voltage source 9 has the voltage higher than the threshold. The driving voltage source 8 is operated by a voltage source controller 9a, and the driving voltage lower than the threshold between the gate and the source is impressed between the gate and the source of the switching element 1, whereby the capacity C formed in parallel between the gate and the source is previously charged. Next, the driving voltage source 9 is operated and the driving voltage higher than the threshold voltage is impressed, whereby the switching element 1 is operated. |
