A thyratron is a type of gas filled tube used as a high energy electrical switch and controlled rectifier. Triode, Tetrode and Pentode variations of the thyratron have been manufactured in the past, though most are of the triode design. Gases used include mercury vapor, xenon, neon, and (in special high-voltage applications or applications requiring very short switching times) hydrogen. Unlike a vacuum tube, a thyratron can't be used to amplify signals linearly. In the 1920s Thyratrons were deri… (More on Thyratron)