| 摘要 |
PROBLEM TO BE SOLVED: To provide a drive method where the charging squence of a change pump capacitor is simplified so as to reduce the time spent for a device design by eliminating a voltage protective circuit and optimum design necessary to determine the capacity of the charge pump capacitor. SOLUTION: Almost at the same time when control power supply is inputted and prescribed control power voltage VPS is applied, the charging pulse of a charge pump capacitor is given, and a control signal VD is outputted from a drive circuit, so that a power transistor is ON in pulse and the capacitor begins to be charged. The charging pulse is given even after the charge pump capacitor has been charged and stops just before a PWM signal is applied. |
