"THYRISTOR" . . "A semiconductor device that is a three-terminal semiconductor rectifier made up of four layers, p-n-p-n, so that when the fourth is positive with respect to the first, a voltage pulse applied to the third layer initiates a flow of current through the device which continues as long as it is greater than some minimum value." . "THYRISTOR" . "9260200" . "Oxford English Dictionary (OED)" . "Qualified" . "RDS876014" . "u20683" . "2006.06.14" .