A recently developed three-stage Darlington transistor is described which has been specifically designed for direct off-line power control. The device features fast, low-loss switching with direct drive from an integrated circuit. The transistor has been designed with a very extensive safe operating area so that a snubber network is not required. The device is sufficiently robust to survive a number of system fault conditions and when used in conjunction with a suitable drive circuit, it can even withstand a short circuit load without damage.