automatic frequency control loop

The phase- locked loop is one kind of control system which is able to achieve phase automatic lock, to compose frequency and to trace demodulation system.

锁相环路是一种能实现相位自动锁定的控制系统，主要用于频率合成及跟踪解调系统。

The phase-locked system is a closed loop automatic control system that can follow the frequency and phase of the input signals.

锁相系统是一个能够跟踪输入信号频率和相位的闭环自动控制系统。

The condenser pump frequency conversion revolution plays a key role in the condensed water system automatic control loop.

凝结泵变频改造对凝结水系统中的自动控制系统影响很大。