Tic
Complex motor tics are typically more purposeful-appearing and of a longer nature. They may involve a cluster of movements and appear coordinated. Examples of complex motor tics are pulling at clothes, touching people, touching objects, echopraxia (repeating or imitating another person's actions) and copropraxia (involuntarily performing obscene or forbidden gestures).
Thyristor drive
A thyristor drive is a motor drive circuit where AC supply current is regulated by a thyristor phase control to provide variable voltage to a DC motor.