As discussed in the textbook , the power thyristor was developed as a replacement for the thyratron, a vacuum tube used for power applications prior to the advent of solid-state devices. The simple construction of these structures using P-N junctions enabled commercialization of devices in the 1950s. These devices were found to be attractive from an applications viewpoint because they eliminated the need for the cumbersome filaments required in vacuum tubes and were much more rugged and smaller in size. The power thyristor provides both forward and reverse voltage blocking capability, making it well suited for AC power circuit applications. The device can be triggered from the forward-blocking off-state to the on-state by using a relatively small gate control current. Once triggered into the on-state, the thyristor remains stable in the on-state even without the gate drive current. In addition, the device automatically switches to the reverse-blocking off-state upon reversal of the voltage in an AC circuit. These features greatly simplify the gate control circuit, relative to that required for the power transistor, reducing its cost and size.
KeywordsBreakdown Voltage Anode Current Anode Voltage Bipolar Transistor Drift Region
- 1.B.J. Baliga, “Fundamentals of Power Semiconductor Devices”, Springer-Science, 2008.Google Scholar