General Science

  • noun a semiconductor device with three electrodes in which a signal to one electrode causes an independent current to flow between the other two

Cars & Driving

  • noun a silicon-controlled rectifier which converts alternating current to a unidirectional current


  • A solid-state equivalent of a thyratron. Examples includes SCRs, and three-layer diodes.
  • A semiconductor device with four layers, p-n-p-n, which has an input terminal, or gate, output terminal, or anode, and a terminal common to both called cathode. Used, for instance, as a solid-state switch that turns large amounts of power on and off very quickly. Also called SCR (1).