VS-50TPS12 Phase Control Thyristor Vishay VS-50TPS12 Phase Control Thyristor is a high-voltage silicon rectifier designed for medium power switching and phase control applications. The glass passivation technology enables reliable operation of up to a 150°C junction temperature. Vishay VS-50TPS12 Phase Control Thyristor is designed and qualified according to JEDEC JESD 47 and comes in a TO-247AD 3L package. Typical usage is in input rectification crowbar (soft start), AC switch motor control, uninterruptible power supply (UPS), welding, and battery charges.