Silicon Controlled Rectifier

(SCR) A solid state switch, sometimes referred
to as a thyristor. The SCR has an anode,
cathode and control element called a gate.
SCR’s are turned on by a voltage pulse applied
between the gate and cathode. They are turned
off when the current between the cathode and
anode reaches zero. The device provides
controlled rectification since it can be turned on
at will. The SCR can rapidly switch large
currents at high voltages. They are small in size
and low in weight.