A thyristor is a solid-state component consisting of alternating P-type and N-type material layers. It remains completely off until a small current pulse at the gate terminal triggers it into conduction, after which it stays latched on until the main current drops below a holding threshold. They are the backbone of high-power AC control, used in motor drives, light dimmers, and high-voltage DC transmission.
Heard on the job
The motor drive keeps blowing the main thyristor because the snubber circuit isn't suppressing the voltage spikes.
Insider tip
Unlike a transistor, you cannot turn off a standard thyristor by removing the gate signal; the main current must fall to zero to unlatch it.
Also heard as
- SCR
- silicon-controlled rectifier