| 摘要 |
PURPOSE:To completely turn ON a MOSFET even if a battery power voltage decreases by providing a booster for increasing the power source voltage of a control pulse generator of speed control means from the battery power voltage. CONSTITUTION:Speed control means 4 applies a pulse Pc of a width in response to a deviation between a speed signal from a DC motor 1 from a frequency generator FG and a speed reference sgnal to a MOSFET 2. On the other hand, a voltage V'B raised from a battery power voltage VB by a booster 5 is obtained, and the voltage V'B is used as a power source voltage of a control pulse generator of speed control means 4. Thus, even if a motor current is increased to decrease the battery power voltage, the MOSFET can be completely turned ON. |
