Draw a symbol and neat labeling V-I characteristics of GTO and explain its operation.

1 Answer

Answer :

Ans: Symbol and V-I characteristics of GTO:

image


Operation of GTO: i) As the applied anode to cathode voltage is increased above zero, very small current (leakage current) flows through the device. Under this condition the GTO is said to be off. It will be continued till the applied voltage reaches the forward Breakover voltage (VBRF). ii) If the anode-cathode (applied) voltage exceeds the breakover voltage, the device conducts heavily and the GTO is turned ON. The anode to cathode voltage decreases quickly because, the GTO offers very low resistance when it is ON, hence it drops very low voltage across it. iii) At this stage the GTO allows more current to flow through it. The amplitude of the current is depending upon the supply voltage and load resistance connected in the circuit. iv) If the value of the gate current Ig is increased above zero, the GTO turns ON even at lower anode-cathode voltage (less than forward breakover voltage, VBRF). v) If the polarity of applied voltage is reversed, we get the reverse characteristics. vi) In reverse direction GTO breaks down at very low voltage (VBRR). The reverse breakdown voltage is of the order of 20 to 30 volt only. 

Related questions

Description : Draw symbol & V-I characteristics of (i) LASCR (ii) DIAC (iii) TRIAC

Last Answer : (i) LASCR:  (ii) DIAC:  (iii) TRIAC: 

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 : Which of the following does not show non-linear V-I characteristics? (A) Schottky diode (B) Tunnel diode (C) Thermistor, at a fixed temperature (D) p-n Junction diode.

Last Answer : Which of the following does not show non-linear V-I characteristics? (A) Schottky diode (B) Tunnel diode (C) Thermistor, at a fixed temperature (D) p-n Junction diode.

Description : Draw the symbol of GTO and TRIAC.

Last Answer : 1) GTO: 2) TRIAC: 

Description : Draw a neat labelling V-I characteristics of SCR and explain the region

Last Answer : (i) Latching current: It is the minimum anode current required to maintain the SCR in the conduction state just after turn-on and the gate signal has been removed.  (ii) Holding current: It is the minimum anode current required to hold the conducting SCR in the ON state. 

Description : How GTO is advantages over SCR

Last Answer : i) It is turned-off by negative gate pulse. ii) No commutation circuit required, reducing the cost, size, weight and volume of the circuit. iii) As commutation choke is not used, the associated acoustic ... turn off time permits high switching frequency. v) It has higher di/dt rating at turn-off. 

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 : How is the GTO turned off? A) By using a commutation circuit B) By applying reverse gate pulse C) By using a latch-up circuit D) By reverse anode current pulse 

Last Answer : How is the GTO turned off? A) By using a commutation circuit B) By applying reverse gate pulse C) By using a latch-up circuit D) By reverse anode current pulse 

Description : basic gate drive circuit of GTO

Last Answer : basic gate drive circuit of GTO

Last Answer : GTO can be turned on by providing positive pulse to the gate terminal and it can be turn off by providing negative pulse to gate terminal.

Description : Explain the electrical characteristics of transformer.

Last Answer : Transformer electrical characteristics: Area of primary and secondary conductors, Apri and Asec: Winding loss Pw: Flux density and core loss: Leakage inductance: ... transformer span. The rise in temperature may breakdown insulation which may cause failure of the transformer.

Description : What are the desirable characteristics of ideal switch?

Last Answer : Desirable characteristics of the ideal switch: It is desirable to have power switches characteristics closer to ideal switch. The ideal switch should have the following characteristics. Zero resistance when ... . 100% efficiency. Able to control power flow with zero power dissipation.

Description : Explain the characteristics of solar cell.  

Last Answer : Characteristics of solar cell : Explanation :- Solar cells produce direct current ( DC ) electricity and current times voltage equals power, so we can create solar cell I-V curves representing ... system so that it can operate as close to its optimal peak power point (MPP) as possible.

Description : Diode VI characteristics

Last Answer : Diode VI characteristics

Description :  basic characteristics of sound signal.

Last Answer : Level and loudness: The amplitude of a sound wave determines its loudness or volume. A larger amplitude means a louder sound, and a smaller amplitude means a softer sound. The loudness of a ... the reproducing system should be capable of handling the maximum and minimum power in the same ratio. 

Description : Compare characteristics of asynchronous and synchronous transmission mode (four points). 

Last Answer : Synchronous transmission Asynchronous transmission 1. Synchronous transmission are synchronized by an external clock. 1. Asynchronous transmission are synchronized by special signals along the transmission ... for transferring a small amount of data as it is simple and economical.

Description : State characteristics of force.

Last Answer : i) Magnitude: The quantity of force e.g. 10 N, 100 kN etc.  ii) Direction: It is the line along which the force acts. It is also called as line of action of the force.  iii) Point of ... .  Push: If the arrow head is pointed towards the point of application, the nature of the force is push.

Description : What is the smallest unit of a compound with the same chemical characteristics?

Last Answer : The molecule is the smallest unit of a compound with the same chemical characteristics.

Description : The following is/are the characteristics of SF6 circuit breakers:  (A) It does not need an auxiliary breaking chamber (B) Short break time of 2 to 2.5 cycles (C) All of the above (D) None of the above

Last Answer : The following is/are the characteristics of SF6 circuit breakers:  (A) It does not need an auxiliary breaking chamber (B) Short break time of 2 to 2.5 cycles (C) All of the above (D) None of the above

Description : The terminal characteristics of a dc generator suitable for electric welders is (A) separately excited generator (B) shunt generator (C) series generator (D) differentially compounded generator

Last Answer : The terminal characteristics of a dc generator suitable for electric welders is differentially compounded generator

Last Answer : The desirable static characteristics of a measuring system are accuracy, sensitivity and reproducibility.

Last Answer : The speed/load characteristics of a universal motor is same as that of D.C. series motor.

Description : Give the operation of single phase full wave bridge controlled converter with RL load with a neat diagram. Also draw its waveform.

Last Answer : Single phase fully control bridge converter with RL load: 1. During positive half cycle of input voltage, T1 and T2 are forward biased and during negative half cycle, T3 and T4 are forward biased. Therefore, T1-T2 ... cycle till the firing of next pair of SCRs as shown in the waveform.

Description : Draw a neat diagram of 1Ф half wave controlled converter with RL load. Give its operation.

Last Answer : Single phase fully controlled half wave converter:  The circuit diagram of single-phase half-wave controlled rectifier with RL load and without freewheeling diode is shown in Fig. (a). The SCR T is ... , when again pulse is applied, the SCR is turned on & the above cycle is repeated. 

Description : Draw the V-I characteristics of power transistor. 

Last Answer : V-I characteristics of power transistor:

Description : Explain auxiliary commutation with a neat diagram. Also draw its waveform.

Last Answer : Auxiliary Commutation At start, the Ta is triggered and turned on to carry the load current. Due to the resonant circuit R-L-C, the current initially rises, attains peak and then falls to ... , the firing of auxiliary SCR commutates the main SCR, hence name is auxiliary commutation.

Description : With neat sketch explain four modes of operation of a TRIAC? 

Last Answer : Modes of operation of a TRIAC: There are four different operating modes of TRIAC:  1) MT2 and gate are positive with respect to terminal MT1(Mode1) : Here terminal MT2 is positive ... junction P2-N2 is forward biased, current carriers are injected and therefore, the TRIAC is turned on. 

Description : Explain the operation of UPS with a neat block diagram.

Last Answer : Uninterruptible-Power-Supplies (UPS): A block diagram of UPS system is shown in figure. It essentially consists of four major components: i)Rectifier (or battery charger) ii) ... . Due to fast action requirement, transfer switch can be implemented by fast acting semiconductor devices.

Description : Explain the operation of RC triggering circuit with neat diagram.

Last Answer : RC triggering circuit: The RC half-wave triggering circuit is as shown in the figure. During negative halfcycle of supply voltage vs, the capacitor C charges through diode D2 and load, ... be triggered at 0° & 180° because the supply voltage is zero and less than finger voltage. 

Description : Draw construction of SCR using two transistor model. Explain its operation.

Last Answer : Two Transistor Model of SCR or Thyristor

Description : A modern power semiconductor device IGBT is combines the characteristics of a) BJT and MOSFET b) FCT and GTO c) SCR and MOSFET d) SCR and BJT

Last Answer : Ans: BJT and MOSFET

Description : Explain the operation of a full wave bridge rectifier with π filter using a neat diagram. Draw input and output waveforms.

Last Answer : During positive half-cycle of input, the secondary voltage VAB is positive, so diodes D1 and D2 forward biased and D3 and D4 reverse biased. The load current flows from terminal A ... smooth DC voltage appears across the load. The input and output waveforms are shown in the figure.

Description : What is photodiode? Draw the symbol and explain operation of photodiode. 

Last Answer : A photodiode is a light detector that converts light into an electrical current. A photodiode is a semi-conductor device, with a p-n junction and an intrinsic layer between p and n layers ... current is independent of reverse bias voltage. Reverse current is mostly depends on the light intensity.

Description : Explain with neat sketch construction of PIN Diode. Draw its characteristics in reverse bias mode. 

Last Answer : Construction A PIN diode is made up of three semiconductor materials; two heavily doped P- and N- type material separated by an intrinsic (undoped) semiconductor (I) as shown in above figure ... . This advantage allows the PIN diode to process even weak signals.  Characteristics

Description : Draw amplitude modulated waveform in time domain and frequency domain with proper labeling.

Last Answer : AM in Time domain  AM in frequency domain

Description : When Graphic Products decided to go international with its marketing effort, it adopted a totally global approach. Which one of the following factors did GP MOST likely experience difficulty with as the ... ? A) Branding B) Product characteristics C) Packaging D) Labeling E) Advertising

Last Answer : E) Advertising

Description : Which symbol will be used to denote an micro operation. a. (*) b. (v) c. Both d. None

Last Answer : b. (v)

Description : Draw symbol of (i) Tray Dryer (ii) Plate column (iii) Packed column (iv) Jaw crusher (v) Strirrer (vi) Ball mill.

Last Answer : i)Tray dryer:   ii)Plate column:    iii)Packed column:   iv) Jaw crusher:   v) Stirrer:   vi) Ball mill  

Description : With neat diagram explain synchronized UJT triggering circuit.

Last Answer : Line Synchronized UJT triggering circuit: The UJT is almost ideal as a firing device for SCRs. There are 2 main reasons for the compatibility between UJTs and SCRs. Firstly, the UJT produces a ... , the SCR is sure to have the right polarity between the anode and cathode for turning on.

Description : With neat circuit diagram explain working of emergency light system. 

Last Answer : Emergency lighting system:  In the residential, commercial and industrial areas, the illumination system work with available AC supply. In the event of AC supply failure, partial illumination can be ... glows. In rthis way, on failure of AC supply, light is obtained from DC supply.

Description : Draw and explain V-I characteristics of a P-N junction diode.

Last Answer : V-I Characteristics of a P-N junction: V-I characteristics of a Diode: The V-I characteristics can be divided in two parts. 1. Forward characteristics. 2. Reverse ... plot a graph with reverse voltage on horizontal axis and current on vertical axis, we obtain reverse characteristics.

Description : Describe with neat sketch the constructional details of IGBT.

Last Answer : Construction: Insulated gate bipolar transistor or IGBT, is a solid state devices primarily used as an electronic switch which, as it was developed, came to combine high efficiency and fast ... layer and p+ emitter constitute a BJT with a wide base region and hence small current gain.

Description : working of SMPS with neat block diagram.

Last Answer : Diagram:  Working principle:-  Rectifier and filter:- It converts the ac supply voltage to a pulsating dc, which is then filtered out to reduce the amount of ripple content. ... PWM controller provides a duty-cycle that varies pulse by pulse to provide an accurate dc output voltage.

Description : Describe with neat sketch the construction and working principle of MOSFET.

Last Answer : Construction and working principle of MOSFET:  A) Depletion type MOSFET: Construction: The N-channel depletion type MOSFET is formed on P-type silicon substrate with two heavily ... accumulation of electrons and hence more current. Thus the MOSFET is a gate voltage controlled device.

Description : Draw the circuit diagram of battery charger using SCR and explain it’s working.

Last Answer : Battery charger circuit using SCR: The figure shows the battery charger circuit using SCR. A 12V discharged battery is connected in the circuit and switch SW is closed. The singlephase 230V ... not fired. In this way, after full charging, further charging is automatically stopped.

Description : For a class D commutation, answer the following: i) Explain the operation with circuit diagram. ii) Interpret with waveforms.

Last Answer : Class D commutation: This is also called as auxiliary commutation because it uses an auxiliary SCR to switch the charged capacitor across conducting SCR to turn it off. In this scheme, the main ... make SCR1 forward biased and keep ready for next triggering. The above cyclic process is repeated.

Description : Explain the series and parallel operation of MOSFET. Which is suitable and why?

Last Answer : Series operation of MOSFET: To increase voltage handling capability MOSFETs are connected in series. When the MOSFETs are connected in series each MOSFET should turn on and turn off ... on and turn off time and transconductance. Each MOSFET should share current equally.  

Description : Also, highlight the problem faced during parallel operation.

Last Answer : Parallel operation of IGBT: Parallel operation of IGBT is done for obtaining high current rating. Paralleling of IGBT reduces conduction losses and thermal stress. IGBT combines the qualities of ... . IGBTs must share losses equally otherwise IGBT may get failure due to thermal differences.

Description : Draw V-I characteristics of p-n junction diode? Define static and dynamic resistance of diode.

Last Answer : Static Resistance: The resistance offered by a p-n junction diode when it is connected to a DC circuit is called static resistance.  (OR) It is the ratio of DC voltage applied across diode ... The dynamic resistance of a diode is the ratio of change in voltage to the change in current.