本文介绍一种基于PLL 锁相环(PHASE LOOK LOOP)工作原理的直流微电机数字调速系统。采用这种工作原理,极大地简化了设计工作,免除了复杂的计算,控制电路简单可靠。实验结果验证了该原理的可行性,证明具有宽调速范围、高稳定性和高精度指标。 This article describes a PLL-based phase-locked loop (PHASE LOOK LOOP) working principle of DC micro-motor digital speed control system. Adopting this kind of working principle, has simplified the design work enormously, has avoided the complicated computation, the control circuit is simple and reliable. The experimental results verify the feasibility of this principle and prove that it has wide speed range, high stability and high precision.