Thyristors, also known as silicon controlled rectifiers (SCR), are semiconductor devices that can act as electronic switches to control circuits with high voltage and current levels. Though thyristors are relatively uncommon components, they are highly useful in controlling power circuits. As such, they are ideal for many power control applications, especially in those where current and voltage levels are elevated. Despite this, thyristors can also be useful in low power applications such as light control, power supply protection, and others. Thyristors are simple parts and relatively inexpensive, making them a helpful solution for many circuits.