| 摘要 |
PURPOSE:To improve the control responsiveness and to prevent the generation of a large surge voltage by connecting a constant voltage having a specific Zener voltage in parallel with a resistor and connecting them in series with the gate of a MOSFET. CONSTITUTION:A resistor 10 and the constant voltage diode having a Zener voltage smaller than the voltage difference between the maximum and minimum voltages of a DC power supply fed between a gate and a source of the MOSFET 1 and larger than the voltage difference between the minimum value of the DC power supply and the threshold voltage of the MOSFET 1 are connected in parallel and they are connected in series with the gate of the MOSFET 1. Thus, in switching the gate by the switching element, the gate potential is larger than the Zener voltage of the constant voltage diode 12 and a gate current flows through the constant voltage diode 12, while the gate potential of the MOSFET 1 is decreased from the maximum value of the voltage of the DC power supply to the threshold voltage. Thus, the control responsiveness is improved and the generation of a large surge voltage is prevented. |
