| 摘要 |
PURPOSE:To minimize a switching time and reduce a loss in switching in an inverter. CONSTITUTION:When an output current signal from an inverter is reduced and the voltage is lowered than a reference voltage (Va), a comparator 16a starts to operate and a switching element 2a is driven through buffers 14 and 14a. A discharged current from a gate is passed through gate resistors 15 and 15a. The gate resistors 15 and 15a are connected in parallel and the apparent resistance is reduced so that an input capacity of the switching element 2a has a shorter discharging time. Then, the switching time is reduce. In addition, a comparator 16b, 16c and so on that become lower than reference voltages (Vb, Vc, and so on) are sequentially operated. In this way, the switching time of the switching element 2a is reduced, and the loss in switching is much reduced. As for a surge voltage, a switching time is reduced, but the output current signal from the inverter is made smaller, so the surge voltage is held almost at the same level as before. |
