To control stepping motors, the balance bridge power drive circuit is made up by TDA1521 integrated audio power amplifier, the pulse allotter is made up by the parallel ports of computer and latches.

双回转机构的步进电机控制电路TDA1521频集成功率大器组成平功率驱动电路，计算机并行口经过锁存器构成脉冲分配器。