What is meant by firing angle of thyristor?

1 Answer

Answer :

The point at which SCR is triggered is known as firings angle of thyristor.

Related questions

Description : Define: i) Firing angle ii) Conduction angle

Last Answer : i) Firing angle: The firing angle of a thyristor is defined as the angle between the zero crossing of the applied voltage and the instant at which the thyristor is triggered or fired. It is a ... off. It is a measure of the duration for which the thyristor conducts current during each AC cycle.

Description : When the firing angle a of a single-phase, fully controlled rectifier feeding constant direct current into a load is 30°, the displacement power factor of the rectifier is

Last Answer : When the firing angle a of a single-phase, fully controlled rectifier feeding constant direct current into a load is 30°, the displacement power factor of the rectifier is √3/2

Description : what is firing angle?

Last Answer : Firing angle is time in electrical degrees from the instant the valve voltage is positive to the application of firing pulse to the valve (start of conduction). Also called delay angle.

Description : Thyristor can be protected from over voltages by using

Last Answer : Thyristor can be protected from over voltages by using Voltage clamping device

Description : Leakage current flows through the thyristor in

Last Answer : Leakage current flows through the thyristor in Forward blocking mode and Reverse blocking mode.

Description : Is a SCR a thyristor?

Last Answer : Yes, SCR is a thyristor. Thyristor is the family and SCR is the member of that family but SCR is universally known as thyristor.

Description : How is a thyristor used to convert AC to DC?

Last Answer : thyristor

Last Answer : Yes ,it is one of the main advantage using thristors as a  switch in DC  circuit ,it has a high current gain

Description : Explain thyristor gate drive circuit.

Last Answer : Thyristor Gate Drive Circuit: The thyristor can be turned on by pulse voltage signal at gate terminal and it does not require continuous drive signal like the transistor. The gate ... circuit provide required minimum gate voltage and gate current then the thyristor conducts properly.

Description : parallel operation of MOSFET can be done more easily as compared to thyristor. why?

Last Answer : Parallel operation of MOSFET can be done more easily as compared to thyristor because the resistance of MOSFET is increases with increase in temperature. MOSFET have the positive temperature coefficient. In ... the parallel operation of MOSFET can be done more easily as compared to the thyristor.

Description : what are the disadvantages of thyristor?

Last Answer : Disadvantages of thyristor The silicon controlled rectifier (SCR) is unidirectional devices, so it can control power only in DC power during positive half cycle of AC supply. Thus only DC power is ... cycle. It cannot be used at higher frequencies. The gate current cannot be negative

Description : write short notes on thyristor CSI .

Last Answer : Current-source inverter (CSI) is an inverter with a DC current input. Current source inverters are most commonly used in very high power AC motor drives.

Description : Draw the structural diagram of GTO. Explain briefly the switching behavior of GTO with the help of appropriate voltage and current waveform.

Last Answer : Gate Turn Off Thyristor (GTO) Conventional Thyristor can be turned on with gate terminal but can not turn off from gate terminal. But in case of Gate Turn Off Thyristor (GTO), we can turn it on and off ... subdivided as storage period (Ts), fall period (Tp) and tail period (Tt).

Description : Describe the working principle of Thyristor operated dimmer with the help of circuit diagram.

Last Answer : Thyristor operated dimmer: A popular thyristor operated dimmer circuit employ TRIAC-DIAC phase control for low AC power control. During each half-cycle, the capacitor charges through (R1+VR1). When the ... time constant {C (R1+VR1)}. Thus by reducing VR1 the lamp brightness can be increased.

Last Answer : By using some circuit the forward DC current of thyristor is forced to zero is called forced commutation.

Last Answer : Natural commutation is also called as line Communication. The turning off of thyristor due to AC supply is called natural commutation or line commutation. If the thyristor is connected to AC supply ... connected to positive and anode terminal get connected to negative, this turns off the thyristor.

Last Answer : No we cannot turn off normal thyristor using Gate.

Last Answer : Thyristor conducts when the anode voltage is greater than cathode and when the current provided to Gate.

Last Answer : Thyristor have three terminals anode, cathode and Gate.

Description : thyristor can be turned off by?

Last Answer : Thyristor can be turned off by making anode potential equal to cathode potential or by making anode potential less than cathode potential.

Last Answer : Thyristor commutation means turning off thyristor.

Last Answer : Thyristor can only be turned on by small gate pulse but it cannot be turn off by using gate hence thyristor is called semi controlled device.

Last Answer : Thyristor can be turn on by positive gate pulse and the current will continue to flow through the device even when the gate voltage is low hence thyristor is called latching device.

Description : Thyristor Switched Capacitor (TSC)

Last Answer : Thyristor Switched Capacitor (TSC)  TSC is a static compensator. TSC is use for compensating reactive power. Compensation is required for voltage regulation, increasing stability, ... compensating device like TCS phase angle between voltage and current can be maintain.

Description : Explain the concept of lagging and leading phase angle by waveform.

Last Answer : i) Leading phase angle :  When two ac quantities of same frequency do not attain their respective zero or peak values simultaneously, then the quantities are said to be out-of-phase quantities. The ... Similarly, in the second diagram, the voltage is said to be lagging the current by  Φ.

Description : How to find total impedance Z, current I and Impedance angle ?

Last Answer : How to find total impedance Z, current I and Impedance angle ?

Description : Phase margin is the amount of angle to make the system  (1) Oscillatory (2) Stable (3) Unstable (4) Exponential

Last Answer : Phase margin is the amount of angle to make the system Unstable 

Description : The power factor angle and torque angle of a salient pole synchronous generator drawing a current of 1.0 pu from a lagging load are 45o and 15o, respectively. The direct axis and quadrature axis currents, respectively, are (A) 0.5 pu ... pu, 0.5 pu (C) 0.707 pu, 0.707 pu (D) 0.5 pu, 0.5 pu

Last Answer : The power factor angle and torque angle of a salient pole synchronous generator drawing a current of 1.0 pu from a lagging load are 45o and 15o, respectively. The direct axis and quadrature axis currents, respectively, are 0.866 pu, 0.5 pu

Description : Torque angle for the synchronous machine is the angle between (A) stator magnetic field and rotor magnetic field (B) stator magnetic field and net magnetic field in the air gap (C) rotor magnetic field and net magnetic field in the air gap (D) excitation voltage and impedance voltage drop

Last Answer : Torque angle for the synchronous machine is the angle between rotor magnetic field and net magnetic field in the air gap

Description : The product of apparent power and cosine of the phase angle between circuit voltage and current is?

Last Answer : In parllpar reasonans RLC circuit the current is

Description : What will be the phase angle between two alternating waves of equal frequency, when one wave attains maximum value the other is at zero value ?

Last Answer : 90° will be the phase angle between two alternating waves of equal frequency, when one wave attains maximum value the other is at zero value.

Description : The r.m.s. value of a sinusoidal A.C. current is equal to its value at an angle of______degrees.

Last Answer : 45

Description : Two waves of the same frequency have opposite phase when the phase angle between them is?

Last Answer : Two waves of the same frequency have opposite phase when the phase angle between them is 180°.

Description : Tangent of angle of friction is equal to?

Last Answer : Tangent of angle of friction is equal to coefficient of friction.

Description : Angle of friction is the?

Last Answer : Angle of friction is the angle between normal reaction and the resultant of normal reaction and the limiting friction.

Last Answer : If the current in a capacitor leads the voltage by 80°, the loss angle of the capacitor is 10°.

Last Answer : The coupling angle or load angle of synchronous motor is defined as the angle between the rotor and the stator poles of opposite polarity.

Description : What is the maximum value of torque angle in synchronous motor?

Last Answer : The maximum value of torque angle in synchronous motor is 90 degrees electrical.

Description : The synchronous motor will develop maximum power when the load angle is?

Last Answer : The synchronous motor will develop maximum power when the load angle is 900.

Description : Thyristor controlled phase angle regulator

Last Answer : Thyristor controlled phase angle regulator

Description : what is TCSC?

Last Answer : Thyristor Controlled Series Capacitor (TCSC)

Description : A single-phase fully controlled thyristor bridge ac-dc converter is operating at a firing angle of 25o and an overlap angle of 10o with constant dc output current of 20 A. The fundamental power factor (displacement factor) at input ac mains is  (A) 0.78 (B) 0.827 (C) 0.866 (D) 0.9

Last Answer : A single-phase fully controlled thyristor bridge ac-dc converter is operating at a firing angle of 25o and an overlap angle of 10o with constant dc output current of 20 A. The fundamental power factor (displacement factor) at input ac mains is 0.78

Description : In a 230 V, 50 Hz single-phase SCR bridge converter operating at a firing delay angle, α and with large R-L load, the input source current is (A) sinusoidal current (B) constant dc current (C) continuous rectangular pulses (D) alternating rectangular pulses

Last Answer : In a 230 V, 50 Hz single-phase SCR bridge converter operating at a firing delay angle, α and with large R-L load, the input source current is alternating rectangular pulses

Description : Is gate turn on mechanism of GTO is similar to conventional thyristor?

Last Answer : Yes gate turn on mechanism of GTO is similar to conventional thyristor.

Description : In a thyristor, the magnitude of anode current will:

Last Answer : In a thyristor, the magnitude of anode current will: Not change with any variation in gate current

Description : A thyristor (SCR) turns off when the  A) Gate pulse is removed B) Gate pulse is applied C) Thyristor current is below holding value D) Anode voltage is made negative

Last Answer : A thyristor (SCR) turns off when the Thyristor current is below holding value

Description : Turn-on of a thyristor (SCR) takes place when  A) Anode to cathode voltage is positive B) Anode to cathode voltage is negative C) Positive current is applied to gate D) Anode to cathode voltage is positive and positive current pulse is applied to gate

Last Answer : Turn-on of a thyristor (SCR) takes place when Anode to cathode voltage is positive and positive current pulse is applied to gate

Description : The number of p-n junctions in a thyristor are  A)1 B) 2 C) 3 D) 4

Last Answer : The number of p-n junctions in a thyristor are  3

Description : Anode current in an thyristor is made up of   (A) electrons only (B) electrons or holes (C) electrons and holes (D) holes only

Last Answer : Anode current in an thyristor is made up of electrons and holes 

Description : In a thyristor, holding current is   (a) More than latching current IL (b) Less than IL (c) Equal to IL (d) Very small

Last Answer : In a thyristor, holding current is Less than IL