| 摘要 |
PURPOSE:To protect a power transistor from breakdown by providing a circuit for producing specific pulse width control signal based on current detection signal, rotation signal and accelerating condition signal of a motor thereby ensuring regenerative brake force even upon droppage of battery voltage. CONSTITUTION:A motor current signal 501 obtained through a shunt resistor 52 is amplified and compared with a reference value, and then it is fed to a switching signal output means 60 by means of a current detection amplifier 30. Regenerative brake force can be ensured sufficiently even upon droppage of battery voltage by providing a pulse width control signal output circuit 10 for feeding a signal 710 from a motor rotation measuring means 70 and a signal 801 from an accelerator 80 to the means 60 and thereby a power transistor can be protected from breakdown. |
