Because to remain in conduction it requires a supply of emitter current. Without a minimum value of emitter current it can't stay in the on position. Most thyristors do not require gate current after they are turned on to remain in conduction
why ujt used as amplifier
voltageCurrent between the two bases of the UJT sets up a voltage gradient in the semiconductor. When the voltage on the emitter of the UJT rises high enough to forward bias the emitter-base junction at the voltage of the interbase gradient where the emitter is located, the UJT "turns on".
A thyristor is a semiconductor device which acts as a switch.
The bulk resistance between the two bases, which will be different for different types of UJT. Consult the datasheet for the value.
No because a mosfet does not work the same as a thyristor. In a thyristor the current flows even when the gate pulse is removed, until the current stops. That is not the case for a FET.
why ujt used as amplifier
Explaine operation of UJT .
UJT is known as Uni Junction Transistor
by connecting the ujt with proper biasing resistors
Types of thyristor firing art
For many people the letters UJT stand for Unitary Junction Transistor.
not a clue a A: It all depends on the thyristor. There are no calculation involved not until you look up the thyristor specifications and decide on the load of the thyristor then you may calculate or more likely choose.
The turn off and turn off mechanism of a thyristor can be best explained by the gate turn-off thyristor. The thyristor uses the reverse bias mechanism.
The On/OFF action in UJT is controlled by emitter current
voltageCurrent between the two bases of the UJT sets up a voltage gradient in the semiconductor. When the voltage on the emitter of the UJT rises high enough to forward bias the emitter-base junction at the voltage of the interbase gradient where the emitter is located, the UJT "turns on".
A thyristor is a semiconductor device which acts as a switch.
no