The principle of frequency conversion is as follows: a sampling voltage is obtained from the discharge gap, and the voltage is used to control an oscillator with a nearly linear change in frequency and voltage. The output pulse is directly used as the operation of the controller and the start-stop signal of the feed, which realizes the control of the feed speed by the gap voltage. Tracking tightness is usually referred to as artificially changing the amplitude range of the sampling voltage supplied to the oscillator.