0 a device, usually a semiconductor, that is used as a switch to control the amount of electricity passing through a particular point -- tyrystor
In the primary low-voltage circuit these are thyristor switches; in the secondary high-voltage circuit it is a gas gap switch.
These stabilizers are based on an autotransformer that is controlled by two sets of thyristor stacks.
The 12 thyristor valves at each side are arranged in a conventional twelve-pulse bridge.
This method of control was the "de facto" method from its development until it was superseded by solid state thyristor systems.
A thyristor is not a proportional device like a transistor.
In some applications this is done by switching a second thyristor to discharge a capacitor into the cathode of the first thyristor.
In this configuration, coarse voltage control is provided by the capacitors; the thyristor-controlled reactor is to provide smooth control.
Smoother control and more flexibility can be provided with thyristor-controlled capacitor switching.
