the fire angle is the angle at which the thyristor starts working...
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.
Thyristor is used for Rectifiying and inverting the power supply in induction furnace. The parallel Resonance Coils (Current Control Furnaces) Control the Furance power up to 40% by controlling the firing angle of the rectifier inverter and remaining 60% controlled by inverter thyristor control. In rectifier they are varying the thyristor firing angle from 15 deg to 45 deg. (in sin wave)
Types of thyristor firing art
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.
A thyristor is a semiconductor device which acts as a switch.
Thyristor is a kind fast acting switch. These are fully controlled switches
The term "Forced commutation" is used when a thyristor is turned off using external components. If a thyristor is used in a DC circuit, when first turned on, it will stay on until the current goes to zero. To turn off the thyristor it is possible to use a Forced commutation circuit. The circuit creates a reverse voltage over the thyristor (and a small reverse current) for a short time, but long enough to turn off the thyristor. A simple circuit consist of a precharged capacitor and a switch (e.g. another thyristor) parallel to the thyristor. When the switch is closed, the current is supplied by the capacitor for a short while. This cause a reversed voltage over the thyristor, and the thyristor is turned off.
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.
There are more than two conditions that can make a thyristor conduct, but the general (functional) ones are: 1) positive voltage form anode to cathode, and 2) a positive voltage on the trigger input (referenced to the cathode) for a standard polarity thyristor. Other conditions can be: A) Anode-Cathode Voltage exceeding thyristor witholding voltage. B) Overtemperature of the thyristor chip C) Faulty thyristor (can be caused by overloads)
Dwell angle is simply the amount of time the points or electronic ignition components are in a closed state to charge the primary side of the ignition coil for firing of the spark plug.. This time is expressed in distibutor rotation, hence the degrees..
S. Enamul Haque has written: 'Power factor improvement of a thyristor controlled, inductive load with fixed capacitor, thyristor-controlled reactor (FC-TCR) type compensator' 'Exact analysis of a thyristor-controlled load in the presence of source impedance and compensated by a fixed filter(two branch filter) thyristor-controlled reactor (FF-TCR) type compensator' 'Exact analysis of thyristor-controlled inductive load with fixed capacitor-thyristor-controlled reactor (FC-TCR) type compensator' 'Exact analysis of a thyristor-controlled load in the presence of source impedance and compensated by a fixed filter-thyristor controlled reactor (FF-TCR) type compensator'