the anode-cathode voltage drops
A silicon-controlled rectifier (SCR) can be triggered (or turned on) by forward voltage, temperature, dv/dt (the derivative of the voltage with respect to time), light, or via a gate (the SCR is triggered when sufficient voltage passes through the gate). Gate triggering is the most common method.
The thyristor functions in such a way that when the anode voltage is greater than the cathode voltage , it is not triggered but only triggers when a gate signal is applied at the gate of the device.
A: Because that is the controlling lead of an thyristor. .To do it otherwise it will be on-off at hi voltage only
since in an FET the value of the current depends upon the value of the voltage applied at the gate and drain...so it is known as voltage controlled device.. for example..in a mosfet..the current from drain to source depends upon the width of the depletion layer..which in turn depends upon the voltage applied on the gate.. so that is the reason
high...
a FET, or Feild Effect Transistor. In a FET, the value of the current depends upon the value of the voltage applied at the gate and drain so it is known as a voltage controlled device. For example: In a MOSFET the current from drain to source depends upon the width of the depletion layer which in turn depends upon the voltage applied on the gate.
yes.
forward-breakover voltage - the voltage at which a device enters the forward-blocking region. The voltage at which the SCR enters the forward-condition region. The value of Vbr(f) is maximum when (Ig=current in gate) Ig=0 and is designate Vbr(f0). When the gate current is increased, Vbr(f) decrease and is designated Vbr(f1), Vbr(f2), and so on, for increasing steps in gate current (Ig1, Ig2, and so on).
forward-breakover voltage - the voltage at which a device enters the forward-blocking region. The voltage at which the SCR enters the forward-condition region. The value of Vbr(f) is maximum when (Ig=current in gate) Ig=0 and is designate Vbr(f0). When the gate current is increased, Vbr(f) decrease and is designated Vbr(f1), Vbr(f2), and so on, for increasing steps in gate current (Ig1, Ig2, and so on).
If negative voltage is applied to the gate of a NMOS, it repels electrons from the channel region towards the bulk of the p-substrate and attaract holes from p-substrate towards the channel. The recombination between holes and electrons causes a deplation of majority carriers in the channel. Enough nagative gate voltage can cause the channel depleted of majority carriers and cuts off the current between the source and the drain. The least negative gate voltage causing this is called gate-source cut off voltage.
A sinusoidal AC waveform is divided up into 360 degrees, with the positive half and the negative half of the waveform combined into a kind of circle. The firing angle simply refers to the point on the waveform, as measured in degrees (thus 'angle') which the thyristor is triggered into conduction. Answer2: Firing angle is the phase angle of the voltage at which the scr turns on. There are two ways of turning an scr on..one is by applying a gate current or by applying a voltage across the scr until it becomes greater than the breakover voltage.... Answer3: Thyristor need gate current and voltage to make it conduct. The firing angle is the sinusoidal increasing voltage. As it rises a voltage is reached with enough power to fire to trigger the gate. That voltage is the angle considering that a sinusoidal is 360 degrees per cycle.
60 volts for stud welding