81 views

1 Answer

Answer :

Yes, SCR is a unidirectional switch.

Like 0 like

Please log in or register to answer this question.

Related questions

242 views

Description : Explain three phase half wave controller or three phase unidirectional controller.

Last Answer : Three phase half wave controller or unidirectional controller:

1 answer
354 views

Description : Explain triggering of SCR using opto-coupler. State its advantages. 

Last Answer : Triggering of SCR using opto-coupler:  A simple opto-coupler based triggering circuit for SCR is shown in the figure. An optocoupler or opto-isolator is a combination of light source ... is small size and light weight device. iii)Interfacing with logic circuits is easily possible.

1 answer
568 views

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.

1 answer
231 views

Description : Explain the thermal triggering method of SCR. Enlist different triggering methods of SCR.

Last Answer : Types of Triggering: 1) Forward voltage triggering 2) Thermal triggering (Temperature triggering) 3) Radiation triggering (Light triggering) 4) dv/dt triggering 5) Gate triggering ... generated leakage current increases. This current gets multiplied internally and thyristor is turned on. 

1 answer
949 views

Description : Explain working of AC circuit breaker using SCR with circuit diagram.

Last Answer : AC Circuit Breaker:  The circuit configuration of static AC circuit breaker using SCR is shown in the figure. When switch S' is closed, the SCRs T1 and T2 are fired in positive ... to non-availability of gate current. Thus the maximum time delay for breaking the circuit is one half-cycle.

1 answer
461 views

Description : Temperature controller using SCR

Last Answer : Temperature controller using SCR The temperature control circuit is used to regulate the temperature. Figure shows the temperature control circuit using thermostat as temperature detector and SCR as ... half-cycle and heater gets connected to source to produce heat and raise the temperature.

1 answer
140 views

Description : Compare SCR and TRIAC

Last Answer : SCR TRIAC It is an unidirectional device. It is a bidirectional device. It is turned-on by only positive gate current. It can be turned-on by either ... applications including lamp dimmer, heating control, zero voltage switched AC relay, small AC motor control etc.

1 answer
599 views

Description : Describe triggering of SCR using UJT relaxation oscillator. 

Last Answer : I need it's operation

2 answers
726 views

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. 

1 answer
836 views

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. 

2 answers
464 views

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

Last Answer : Two Transistor Model of SCR or Thyristor

1 answer
189 views

Description : The SCR would be turned OFF by voltage reversal of applied anode-cathode ac supply frequency of A) 10 kHz B) 10 Hz C) 5 kHz D) 5 Hz 

0 answers
90 views

Description : SCR is more utilized as compared to Triac because it is

Last Answer : SCR is more utilized as compared to Triac because it is available with higher ratings

1 answer
191 views

Description : A 230 V, 50 Hz phase controlled single-phase full-controlled SCR bridge converter draws 15 A constant dc current. If the source inductance is 3 mH, the drop in dc output voltage is (A) 4.5 V (B) 6.75 V (C) 9 V (D) 13.5 V

Last Answer : A 230 V, 50 Hz phase controlled single-phase full-controlled SCR bridge converter draws 15 A constant dc current. If the source inductance is 3 mH, the drop in dc output voltage is 9 V

1 answer
186 views

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

1 answer
107 views

Description : An SCR without any external connections is considered as (A) two diodes in series (B) three diodes in series (C) two n-p-n transistors in series (D) two p-n-p transistors in series

Last Answer : An SCR without any external connections is considered as three diodes in series

1 answer
97 views

Description : Why SCR is called as thyristor?

0 answers
165 views

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.

1 answer
934 views

Last Answer : SCR turned off when the anode current falls below holding current.

1 answer
1.5k views

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.

2 answers
95 views

Description : What is the use of SCR?

Last Answer : SCR are use in lamp dimming, power regulators, motor control, rectifications of high power AC, control of welding machines and also use as switch these are some uses of silicon controlled rectifier.

1 answer
94 views

Description : The device which allows reverse power flow and withstands highest switch frequency is (A) GTO (B) MOSFET (C) IGBT (D) Inverter grade SCR

Last Answer : The device which allows reverse power flow and withstands highest switch frequency is MOSFET

1 answer
162 views

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

2 answers
1.3k views

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.

1 answer
145 views

Last Answer : Because it has a higher switching frequency and heat tolerance.

1 answer
4 views

Description : drive the expression for the  (1)current that commutates the scr, (2)the peak current, (3) conduction time?  in class B,C,D and E.

0 answers
28 views

Description : Purpose of Selective Catalytic Reduction (SCR)

Last Answer : Purpose of Selective Catalytic Reduction (SCR) : 1. It reduces Nox 75% to 90% 2. Converts it in to molecular nitrogen and water vapor 3. It reduces HC emission up to 80% 4. It reduces PM emission 20 to 25%.

1 answer
139 views

Description : An inductor is connected in series with SCR to protect it from A) Excessive high voltage B) Excessive high dv/dt C) Excessive high di/dt D) Excessive large forward current 

Last Answer : An inductor is connected in series with SCR to protect it from Excessive high di/dt

1 answer
160 views

Description : The no-load speed of a single-phase SCR bridge converter fed separately excited dc motor operating at a firing delay angle, α and flux, Φ (A) directly proportional to α and Φ (B) ... proportional to α and inversely proportional to Φ (D) directly proportional to Φ and inversely proportional to α

Last Answer : The no-load speed of a single-phase SCR bridge converter fed separately excited dc motor operating at a firing delay angle, α and flux, Φ directly proportional to α and inversely proportional to Φ

1 answer
176 views

Description : In a 3-phase converter circuit during commutation when one SCR in one phase is turned on to turn-off an SCR in another phase, results in (A) voltage notching (B) harmonic distortion (C) voltage sag (D) voltage swell

Last Answer : In a 3-phase converter circuit during commutation when one SCR in one phase is turned on to turn-off an SCR in another phase, results in voltage notching

1 answer
62 views

Description : How do you test an SCR?

0 answers
2.6k views

Description : Why is pulse train gating preferred over pulse gating? Explain with relevant circuit and waveforms, the pulse train gating of SCRs.

0 answers
3 views

Description : Should I switch to a credit union?

Last Answer : I switched from a bank to a credit union a long time ago. Competitive interest rates, fewer fees, easier loan approvals, better customer service.

1 answer
15 views

Description : How to Replace a Light Switch

Last Answer : How to Replace a Light Switch They say it only takes one idiot to change a light bulb, but to change a light switch requires the skill and carefulness of a handyman. If you have a malfunctioning or a ... doesn't have to be a hassle. Just remember these steps and switching a new switch will be easy.

1 answer
11 views

Description : How to Install a Timer Switch

Last Answer : How to Install a Timer Switch A timer switch is a handy device that automatically turns off a switch after a fixed period of time. This is particularly useful when you have kids at home ... safety precautions when installing switches or anything that might put you in the direct path of electricity.

1 answer
11 views

Description : How To Install A Dimmer Switch

Last Answer : How To Install A Dimmer Switch Having a room with a bright light is good, but there are instances when you need the lights to be lower than what you're accustomed. You need to have a dimmer switch, ... your home. Follow them properly, and you'll be able to fiddle with the light levels in your home.

1 answer
16 views

Description : How to Wire a Three-Way Switch ?

Last Answer : How to Wire a Three-Way Switch A three-way switch is the most common system installed in residential areas. This system is used to control a light and receptacle or more from two different switches ... wires for interior use. #14 wires are suggested to be used for protected circuits at 15 amperes.

1 answer
80 views

Description : Draw & explain touch plate switch using IC555.

Last Answer : It is construct form monostable multivibrator , when metal plates touch by finger then voltage at pin number 2 goes to below 1/3 Vcc then output of lower comparator becomes high hence flip flop set and ... then output of timer goes low and it low till up to the metal plates touch by finger .

1 answer
139 views

Description : Give the function of fuse and switch.

Last Answer : Functions of fuse:  * To break the circuit under fault condition.  * To provide overcurrent protection to the circuit.  * To provide short circuit protection to the circuit.  * To provide ...  * To make the electric circuit manually.  * To break the electric circuit manually.

1 answer
2.7k views

Description : State the function of : i) MCCB ii) ELCB iii) MCB iv) Switch. 

Last Answer : i) MCB: Provide short circuit protection & over load protection to electrical loads.  ii) ELCB: Provides protection by detecting the unsafe magnitudes leakage currents flowing to earth and disconnecting ... rating.  iv) Switch: Make and break the electrical connection to the load manually.

3 answers
60 views

Description : Transfer switch

Last Answer : .embed-container { position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden; max-width: 100%; } .embed-container iframe, .embed-container object, .embed-container embed { position: absolute; top: 0; left: 0; width: 100%; height: 100%; }

1 answer
563 views

Description : How rating of main switch and cable is selected for Industrial Installation.

Last Answer : 1. Rating of Main Switch or Fuse Rating is decided in industrial installation: Rating of main switch or fuse is based up the starting current of motor. For calculating starting current is considered 2 ... take 1.5 times the rated current or full load current. & thus cable rating is decided.

1 answer
115 views

Description : Earthing switch is used for?  (A) Measuring of safety voltage (B) Protection of equipment from ground faults (C) Discharging residual energies (D) All of the above 

Last Answer : Earthing switch is used for?  (A) Measuring of safety voltage (B) Protection of equipment from ground faults (C) Discharging residual energies (D) All of the above 

1 answer
198 views

Description : A switch tail ring counter is made by using a single D-FF. The resulting circuit is (A) T-FF (B) D-FF (C) SR-FF (D) JK-FF

Last Answer : A switch tail ring counter is made by using a single D-FF. The resulting circuit is T-FF

1 answer
143 views

Description : A closed switch has a resistance of?

Last Answer : A closed switch has a resistance of zero.

1 answer
93 views

Last Answer : The switch board instruments should be mounted in vertical position.

1 answer
191 views

Last Answer : If the centrifugal switch of a two-value capacitor motor using two capacitors fails to open then Electrolytic capacitor will, in all probability, suffer break down.

1 answer
230 views

Last Answer : Centrifugal switch disconnects the auxiliary winding of the motor at about 70 to 80 percent of synchronous speed.

1 answer
282 views

Last Answer : In a single phase motor the centrifugal switch disconnects auxiliary winding of the motor.

1 answer
892 views

Last Answer : A centrifugal switch is used to disconnect starting winding when motor has picked up about 50 to 70 per cent of rated speed.

1 answer
...