In a thyristor, holding current is

In a thyristor, holding current is 

 (a) More than latching current IL (b) Less than IL (c) Equal to IL (d) Very small
by

1 Answer

Answer :

In a thyristor, holding current is Less than IL

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Related questions

In a thyristor Latching current is ________ than Holding current a) Equal b) Less c) Greater d) None

Description : In a thyristor Latching current is ________ than Holding current a) Equal b) Less c) Greater d) None

Last Answer : Ans: Greater

In thyristor. holding current is

Description : In thyristor. holding current is (A) More than the latching current (B) Less than the latching current (C) Equal to latching current (D) None of the above

Last Answer : In thyristor. holding current is less than the latching current

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

Description : The typical ratio of latching current to holding current in a 20A thyristor is : (A) 5.0 (B) 2.0 (C) 1.0 (D) 0.5

Last Answer : The typical ratio of latching current to holding current in a 20 A thyristor is  2.0

In a thyristor Latching current is than holding current: -

Description : In a thyristor Latching current is than holding current: - a) equal b) less c) greater d) none of the above

Last Answer : In a thyristor Latching current is than holding current: - greater

In a thyristor, the magnitude of anode current will:

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

Anode current in an thyristor is made up of

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 

Leakage current flows through the thyristor in

Description : Leakage current flows through the thyristor in

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

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

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.

A thyristor (SCR) turns off when the

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

Turn-on of a thyristor (SCR) takes place when

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

The number of p-n junctions in a thyristor are

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

Thyristor can be protected from over voltages by using

Description : Thyristor can be protected from over voltages by using

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

What is meant by firing angle of thyristor?

Description : What is meant by firing angle of thyristor?

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

Is a SCR a thyristor?

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.

How is a thyristor used to convert AC to DC?

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

Last Answer : thyristor

Is thyristor a DC switch?

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

Explain thyristor gate drive circuit.

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.

In a thyristor D.C. chopper, which type of commutation results in best performance ?

Description : In a thyristor D.C. chopper, which type of commutation results in best performance ?

Last Answer : voltage commutation

parallel operation of mosfet can be done more easily as compared to thyristor. why?

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.

what are the disadvantages of 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

write short notes on thyristor CSI .

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.

what is gate turn off thyristor (GTO)?

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).

What is holding current and latching current in SCR ?

Description : What is holding current and latching current in SCR? Draw the gate characteristics of an SCR and explain the characteristics. What are the different signals which can be used for turning on SCR by gate control? compare them.

Last Answer : (i) Holding Current: Holding current is defined as the minimum anode current required to maintain conducting SCR in the on-state.  (ii) Latching Current: Latching current is defined as the ... the on-state immediately after the SCR has been turned on and the gate signal has been removed.

What is Thyristor ?

Description : What is Thyristor ?

Last Answer : : A thyristor is a solid state semiconductor device consisting of four layers of P and N-type components. This is especially true of a dual mode switch.

Which of the devices listed is indicated by the electronic symbol lettered as 'A', shown in the illustration? EL-0016 A. Thyristor B. Diode C. Capacitor D. Transistor

Description : Which of the devices listed is indicated by the electronic symbol lettered as 'A', shown in the illustration? EL-0016 A. Thyristor B. Diode C. Capacitor D. Transistor

Last Answer : Answer: B

What does the arrangement at coordinates '62E' shown in the illustration represent? EL-0099 A. Position recording drum and stylus B. Temperature compensating thyristor C. Miniature bridge rectifier D. Twisted wire pair within a shield

Description : What does the arrangement at coordinates '62E' shown in the illustration represent? EL-0099 A. Position recording drum and stylus B. Temperature compensating thyristor C. Miniature bridge rectifier D. Twisted wire pair within a shield

Last Answer : Answer: D

Figure 'B' shown in the illustration represents a/an ____________. EL-0067 A. silicon controlled rectifier B. junction field effect transistor C. diac thyristor D. IG MOS field effect transistor

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A triac thyristor functions as a control device and is basically ________________. A. two NPN transistors in parallel with a common base lead B. a diode in series with a temperature sensitive capacitor C. two back-to-back SCR's with a common gate lead D. a triode tube with an extra heavy grid element

Description : A triac thyristor functions as a control device and is basically ________________. A. two NPN transistors in parallel with a common base lead B. a diode in series with a temperature sensitive capacitor C. two ... -back SCR's with a common gate lead D. a triode tube with an extra heavy grid element

Last Answer : Answer: C

Figure 'A' of the diagram shown in the illustration represents a/an ____________. EL-0078 A. silicon controlled rectifier B. IG or MOS field effect transistor C. triac thyristor D. junction field effect transistor

Description : Figure 'A' of the diagram shown in the illustration represents a/an ____________. EL-0078 A. silicon controlled rectifier B. IG or MOS field effect transistor C. triac thyristor D. junction field effect transistor

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Figure 'B' of the diagram shown in the illustration represents a/an ____________. EL-0065 A. silicon controlled rectifier B. junction field effect transistor C. diac thyristor D. IG or MOS field effect transistor

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What are the different losses that occur in thyristor while operating?

Description : What are the different losses that occur in thyristor while operating?

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Why thyristor is considered as Charge controlled device?

Description : Why thyristor is considered as Charge controlled device?

Last Answer : During the triggering process of the thyristor from forward blocking state to forward conduction state through the gate signal, by applying the gate signal (voltage between gate and cathode) increases the ... By controlling the amount of charge we can control the turning on time of the scr.

Do you know the advantages of speed control using thyristor?

Description : Do you know the advantages of speed control using thyristor?

Last Answer : A: Advantages: 1. Fast Switching Characteristics than Mosfet, BJT, IGBT 2. Low cost 3. Higher Accurate.

What Are The Advantages Of Speed Control Using Thyristor?

Description : What Are The Advantages Of Speed Control Using Thyristor?

Last Answer : Advantages : Fast Switching Characterstics than Mosfet, BJT, IGBT. Low cost. Higher Accurate.

How output frequency is varied in case of a thyristor?

Description : How output frequency is varied in case of a thyristor?

Last Answer : The output frequency is varied by varying the turn off time of the thyristors in the inverter circuit, i.e. the delay angle of the thyristors is varied.

Why circuit turn off time should be greater than the thyristor turn-off time?

Description : Why circuit turn off time should be greater than the thyristor turn-off time?

Last Answer : Circuit turn off time should be greater than the thyristor turn-off time for reliable turn-off, otherwise the device may turn-on at an undesired instant, a process called commutation failure.

What losses occur in a thyristor during working conditions?

Description : What losses occur in a thyristor during working conditions?

Last Answer : a. Forward conduction losses b. Loss due to leakage current during forward and reverse blocking. c. Switching losses at turn-on and turn-off. d. Gate triggering loss.

How can a thyristor turned off?

Description : How can a thyristor turned off?

Last Answer : A thyristor can be turned off by making the current flowing through it to zero.

What are the different methods to turn on the thyristor?

Description : What are the different methods to turn on the thyristor?

Last Answer : a. Forward voltage triggering b. Gate triggering c. dv/dt triggering d. Temperature triggering e. Light triggering

What is Thyristor?

Description : What is Thyristor?

Last Answer : Thyristor is a four or more layer semiconductor device & having 3 or more junctions. It is also called Silicon Controlled Rectifiers (SCR). A healthy SCR must block in both the directions at least 1MQ resistance, a fused SCR will conducts in both directions. 

What is purpose of connecting thyristor bridges in parallel?

Description : What is purpose of connecting thyristor bridges in parallel?

Last Answer : Thyristor bridges are connected in parallel to improve current rating.  

Why reactors are provided in Thyristor bridges?

Description : Why reactors are provided in Thyristor bridges? 

Last Answer : Reactors are provided to limit the rate of rise of current (di/dt) in the device, thereby avoiding possible damage to the device. They also effect a proper sharing of load among thyristor bridges when connected in parallel. 

What is the purpose of RC network across thyristor?

Description : What is the purpose of RC network across thyristor?

Last Answer : RC network across each thyristor protects against Hole Storage Effect.  

What is Thyristor?

Description : What is Thyristor?

Last Answer : Thyristor is a four or more layer semiconductor device & having 3 or more junctions. It is also called Silicon Controlled Rectifiers (SCR). A healthy SCR must block in both the directions at least 1MΩ resistance, a fused SCR will conducts in both directions. 

What is a thyristor ? What are its uses ?

Description : What is a thyristor ? What are its uses ?

Last Answer : A thyristor is a special kind of semi conductor device that uses internal feedback to produce latching action. Use : Used for controlling large amounts of load power in motors, heaters, lighting systems etc ... the latches like a open switch. This latch will always stay in open or close position.  

What is a thyristor? What is an SCR?

Description : What is a thyristor? What is an SCR?

Last Answer : A thyristor is a solid-state semiconductor device with four layers of alternating N and P-type material. They act as bi stable switches, conducting when their gate receives a current trigger, and continue ... ) is a four-layer solid state device that controls current. It is a type of thyristor.

Which of the following problem arises in D.C. motors which are fed from thyristor bridge circuits ? (a) Increased I R losses (b) Increased core losses (c) Poor commutation (d) Change in motor parameters (e) All of the above

Description : Which of the following problem arises in D.C. motors which are fed from thyristor bridge circuits ? (a) Increased I R losses (b) Increased core losses (c) Poor commutation (d) Change in motor parameters (e) All of the above

Last Answer : (e) All of the above

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

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.

What is the difference between SCR and thyristor?

Description : What is the difference between SCR and thyristor?

Last Answer : SCR is a type of thyristor. Like GTO, IGCT, MCT, TRIAC, DIAC etc. are the types of thyristor.

A three-phase, 440 V, 50 Hz ac mains fed thyristor bridge is feeding a 440 V dc, 15 kW, 1500 rpm separately

Description : A three-phase, 440 V, 50 Hz ac mains fed thyristor bridge is feeding a 440 V dc, 15 kW, 1500 rpm separately excited dc motor with a ripple free continuous current in the dc link under all operating conditions, Neglecting the ... at half the rated speed is  (A) 0.354 (B) 0.372 (C) 0.90 (D) 0.955

Last Answer : A three-phase, 440 V, 50 Hz ac mains fed thyristor bridge is feeding a 440 V dc, 15 kW, 1500 rpm separately excited dc motor with a ripple free continuous current in the dc link under all operating conditions, Neglecting the losses, the power factor of the ac mains at half the rated speed is 0.354