Hydrogen thyratron is used as pulse modulator in radar, accelerator etc, typical circuitry as the following. Modulator starts to work, hydrogen thyratron keeps close state. High voltage power charges PFN to a rated value through charge inductance and charge diode. When grid is added to trigger pulse, hydrogen thyratron will be made. PFN discharges through hydrogen thyratron and pulse transformer, pulse transformer outputs a certain pulse width and repeats frequency torque pulse. Pulse width depends on PFN, repeats frequency depends on repeat frequency of trigger pulse.