automatic follow frequency

• 频率自动跟踪

automatic follow frequency的用法和样例：

例句

1. When resonance happens,the induced voltage will reach to its maximum value.Tracking the maximum value can realize the frequency autotracking.
   谐振时，感应电压达到最大值，搜寻感应电压最大值就能实现频率自动跟踪。