Why thyristors are called latching devices?

Why thyristors are called latching devices?

Answer : Thyristor can be turn on by positive gate pulse and the current will continue to flow through the device even when the gate voltage is low hence thyristor is called latching device.

How does a thyristor latch?

Once both transistors are turned on completely (“saturated”), current can flow all the way through both of them—through the entire thyristor from the anode to the cathode. Since the two transistors keep one another switched on, the thyristor stays on—”latches”—even if the gate current is removed.

What is the latching current of a thyristor?

Latching current: Latching current is that minimum current that flows through the device in forward biased condition. Once the device reaches this particular value then the device completely starts conduction even after the removal of the gate pulse. This current is associated with the turn-on process of the thyristor.

What do you need to know about thyristors?

1 The thyristor is a current controlled device. 2 After applying a triggering pulse, the device functions as a rectifier. 3 Even if trigger pulse is provided, the device does not conduct in reverse biased mode. 4 If anode current once surpasses the latching current, then removal of gate pulse does not off the thyristor.

How does a thyristor work as a rectifier?

The thyristor is a current controlled device. As a large anode current is controlled by some small value of gate current. After applying a triggering pulse, the device functions as a rectifier.

What kind of switching device is a thyristor?

The term thyristor is a general name for a family of semiconductor device. Thyristor families consist of large number of switching devices. A thyristor is a solid state power semiconductor device. It has four alternating layer and three junctions J 1, J 2, J 3 of N type semiconductor and P type semiconductor material.