POWER ELECTRONICS QUIZ

If a latching current for the circuit shown in figure is 2 mA. Obtain the value of minimum width of the property turn ON the SCR?

3 µs.

3.1 µs

3.3 µs

3.2 µs

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A single phase one pulse controlled circuit has a resistance R and counter emf E load 400 sin(314 t) as the source voltage. For a load counter emf of 200 V, the range of firing angle control is

30° to 180°.

60° to 180°.

30° to 150°.

60° to 120°.

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A 200 A thyristor is to be operated in parallel with a 300 A thyristor. The ON state voltage drops are 1.5 V and 1.2 Volts. What is the value of resistance R to be connected in series with each thyristor, so that current through the combination is 500 A and each of them is fully loaded ?

0.3 ohm

0.03 ohm

3.0 ohm

0.3 ohm

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The reverse recovery time of diode is trr = 3 ÃŽÂ¼s and the rate off all of the diode current is di/dt = 30 A/ÃŽÂ¼s. The storage charge current QRR is

140 ÃŽÂ¼s.

135 ÃŽÂ¼s.

145 ÃŽÂ¼s.

130 ÃŽÂ¼s.

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ON state voltage drop across SCR lie between the range

1.5 - 2 V.

1 - 1.5 V.

0 - 0.5 V.

0.5 - 1 V.

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A diac has ___________ terminals.

Four

None of these

Two

Three

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The typical time of rising time lies between

90 - 100 µs.

40 - 60 µs.

1 - 4 µs.

10 - 20 µs.

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Which semiconductor device acts like a diode and two transistor?

UJT.

Triac.

Diac.

SCR.

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Which of following is not a power transistor?

IGBTs.

SITS.

COOLMOS.

TRIAC.

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BCT is used for

Low power current control.

Low power phase control.

High power current control.

High power phase control.

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