Editing Silicon controlled rectifier (section)

== Simple SCR circuit ==
[[File:Simple scr circuit.png|thumb|317x317px|A simple SCR circuit with a resistive load]]
A simple SCR circuit can be illustrated using an AC voltage source connected to a SCR with a resistive load. Without an applied current pulse to the gate of the SCR, the SCR is left in its forward blocking state. This makes the start of conduction of the SCR controllable. The delay angle α, which is the instant the gate current pulse is applied with respect to the instant of natural conduction (ωt = 0), controls the start of conduction. Once the SCR conducts, the SCR does not turn off until the current through the SCR, i<sub>s</sub>, becomes negative. i<sub>s</sub> stays zero until another gate current pulse is applied and SCR once again begins conducting.<ref>{{Cite book|title=Power Electronics: A First Course|last=Mohan|first=Ned|publisher=Don Fowley|year=2012|isbn=978-1-118-07480-0|location=United States|pages=230–231}}</ref>