thyristor

A forced commutated thyristorized step-down chopper is shown in the figure. Neglect the ON-state drop across the power devices. Assume that the capacitor is initially charged to 50...

The circuit shown in the figure has reached steady state with thyristor 'T' in OFF condition. Assume that the latching and holding currents of the thyristor are zero. The thyristor...

The single phase rectifier consisting of three thyristors T1, T2, T3 and a diode D1 feed power to a 10 A constant current load. T1 and T3 are fired at α = 60° and T2 is fired at α...

A six-pulse thyristor bridge rectifier is connected to a balanced three-phase, 50 Hz AC source. Assuming that the DC output current of the rectifier is constant, the lowest harmoni...

A single-phase fully-controlled thyristor converter is used to obtain an average voltage of 180 V with 10 A constant current to feed a DC load. It is fed from single-phase AC suppl...

Four power semiconductor devices are shown in the figure along with their relevant terminals. The device(s) that can carry dc current continuously in the direction shown when gated...

For the power semiconductor devices IGBT, MOSFET, Diode and Thyristor, which one of the following statements is TRUE?

The figure below shows the circuit diagram of a controlled rectifier supplied from a 230 V, 50 Hz, 1-phase voltage source and a 10:1 ideal transformer. Assume that all devices are...

The typical ratio of latching current to holding current in a $$20$$ $$A$$ thyristor is

Circuit turn-off time of an $$SCR$$ is defined as the time

An $$SCR$$ is considered to be a semi - controlled device because

A three - phase fully - controlled thyristor bridge converter is used as line commuted inverter to feed $$50kW$$ power $$420$$ $$V$$ $$dc$$ to a three phase, $$415$$ $$V$$ (line),...

A single phase voltage source of magnitude $${V_s}$$ and frequency $$\omega \,\,\left( {rad\,/\,\sec } \right)$$ is connected to an inductance $$L$$ through an antiparallel back-to...

In a commutation circuit employed to turn off an $$SCR$$, Satisfactory turn-off is obtained when.

If a diode is connected in anti - parallel with a thyristor, then

In a thyristor $$dc$$ chopper which type of commutation results in best performance?

Which of the following does not cause permanent damage of an $$SCR?$$

Thysistor circuits that directly convert poly phase $$ac$$ voltage from one frequency to another frequency are called _______.