能够驱动5v-12v直流电机电动小车的驱动不但要求电机驱动系统具有高转矩重量比、宽调速范围、 高可靠性，而且电机的转矩 -转速特性受电源功率的影响，这就要求驱动 具有尽可能宽的高效率区。(The drive of 5V-12V DC motor electric car requires not only the motor drive system with high torque-weight ratio, wide speed range and high reliability, but