Draw & explain operation of phase detector.

Draw & explain operation of phase detector.
by

1 Answer

Answer :

image

image


In phase detector, the op-Amp basically acts as a zero crossing detector. If a sine wave is applied at the i/p, we get square wave at the op-Amp o/p (at point A).


The capacitor C & resistor R, from a passive differentiator so across R we get positive Negative spikes at the point B. 


When positive pulse or spike reaches at the anode of the diode. Hence diode becomes forward biased. Therefore it allows the spike to pass through the load. 


When negative spike will reach at point B, diode is reverse biased. Hence it does not pass the negative spike towards load. Thus we get the output across RL or only positive spike.


It can be used to measure phase angle & two voltages under the phase measurement are applied to two different pulse generation. These voltages are then converted into positive trigger pulse. These pulses are applied to two channel of the CRO. The time duration between the pulses corresponding to voltages represent the phase between them. 

by

Related questions

Draw & explain touch plate switch using IC555.

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 .

Draw the symbol of LED & photodiode.

Description : Draw the symbol of LED & photodiode. 

Last Answer : Symbol of LED & photodiode

Draw block diagram of PLL as a FM demodulator. Explain function of each block.

Description : Draw block diagram of PLL as a FM demodulator. Explain function of each block.

Last Answer : Operation:  The FM signal which is to be demodulated is applied at the input of the PLL.  the PLL is locked to the FM  The error voltage produced at ... using PLL ensures a high Linearity, between the instantaneous input frequency and VCO control voltage (error amplifier output)

Draw and explain RC phase shift Oscillator.

Description : Draw and explain RC phase shift Oscillator.

Last Answer : Circuit diagram of RC phase shift oscillator: WORKING: * Circuit consists of a single stage amplifier in common emitter configuration & RC phase shifting network. * R1, R2, RE provides biasing & CE ... . * The phase shift around the loop is 3600 only at one precise frequency.  

Draw the block diagram of regulated power supply, explain function of each block and draw waveforms of each stage.

Description : Draw the block diagram of regulated power supply, explain function of each block and draw waveforms of each stage.

Last Answer : 1. A step down transformer 2. A rectifier 3. A filter 4. A regulator Operation of Regulated Power Supply:- Step Down Transformer:- A step down transformer will ... regulator. A regulator will maintain the output constant even when changes at the input or any other changes occur.

List different starting methods of three phase synchronous motor. Explain any one of them.

Description : List different starting methods of three phase synchronous motor. Explain any one of them.

Last Answer : Different Starting Methods of Three Phase Synchronous Motor: As synchronous motor is not self starting, different methods of starting are as follows: 1) By using an Induction (Pony) motor 2) ... . The rotor gets pulled into synchronism and starts running at constant speed as a synchronous motor. 

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

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.

Draw and explain V and inverted V curves for synchronous motor.

Description : Draw and explain V and inverted V curves for synchronous motor.

Last Answer : V curves' and inverted V curves' for Synchronous Motor:  V curve:  V curve is a plot of the stator current versus field current for different constant loads. The graph is plotted ... Vcurves of synchronous motor. The highest point on each of these curves indicates unity power factor.

Draw symbol of LED and explain it’s working principle.

Description : Draw symbol of LED and explain it’s working principle.

Last Answer : Construction of LED: The basic structure of LED is shown in fig.(a). The active region exists between the p and n regions. The light emerges from the active side in all the directions when electron hole-pairs ... fig.(c). In this way an LED emits light. This is the principle of operation of LED.

What is PLL? Explain its operation with a block diagram.

Description : What is PLL? Explain its operation with a block diagram.

Last Answer : PLL - A phase-locked loop or phase lock loop is a control system that generates an output signal whose phase is related to the phase of an input signal Block diagram  ... to the input frequency. The phase - locked loop goes through three states free running capture and phase lock.

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

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.

Give the full form of SCADA & HMI.

Description : Give the full form of SCADA & HMI.

Last Answer : Full Form of SCADA and HMI:  SCADA:-Supervisory Control and Data Acquisition  HMI :- Human Machine Interface

Draw the block diagram of PLC.

Description : Draw the block diagram of PLC.

Last Answer : Block diagram of PLC and input/output devices used for PLC Input/output devices - The input module has bank of terminals for physically connecting input devices, like push buttons, limit switches etc. ... is to translate signals from the PLC's CPU into a form that the output device can use.

Draw equivalent circuit of alternator.

Description : Draw equivalent circuit of alternator.

Last Answer : Equivalent circuit of alternator

State different types of electrical signal and draw all types of waveforms.

Description : State different types of electrical signal and draw all types of waveforms.

Last Answer : Types of electrical signals 1) Sine wave 2) Triangular wave 3) Square wave Waveforms

Define resistor and draw symbol of variable resistor.

Description : Define resistor and draw symbol of variable resistor.

Last Answer : Resistor: A resistor is an electrical component that limits or regulates the flow of electrical current in an electronic circuit. Symbol of variable resistor:   

For the parallel operation of single phase transformers it is necessary that they should have?

Last Answer : Necessary conditions required to be satisfied in order to ensure successful parallel operation of single phase transformers:  1. Only transformers having the same phase displacement between primary and secondary ... . 7. The phase sequence must be followed strictly on HV and LV side connection.

Explain MCB and ELCB with connection diagram supplying single phase load.

Description : Explain MCB and ELCB with connection diagram supplying single phase load. 

Last Answer : OR OR Explanation: * MCB provides short circuit protection. * MCB provides overload protection * ELCB provides earth fault protection. * MCB is in series with ... occurs, the ELCB cuts off the power within the time of 0.1 sec. automatically to protect the personnel. 

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

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

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

Explain three phase full wave controller.

Description : Explain three phase full wave controller.

Last Answer : Three phase full wave controller: Three phase full wave controller is also called as the three-phase bidirectional controller. Let the load is star connected so at each phase there are antiparallel connected SCRs. ... conduct at the same time and the third phase will be open.

State the principle of operation of d.c. motor.

Description : State the principle of operation of d.c. motor.

Last Answer : When a current carrying conductor is placed in a magnetic field, the conductor experiences the force. The magnitude of force is given by F = BIL newton  where F – Force   B – maximum flux density   I – Current   L – Length of conductor

Explain the suitability of aluminium as an electrical conductor with respect to its mechanical and electrical properties.

Description : Explain the suitability of aluminium as an electrical conductor with respect to its mechanical and electrical properties. 

Last Answer : Following are requirements of conductor:- i) High conductivity :  Material should have high conductivity, So that * cross section of conductor (size) reduces, * Copper losses reduces, * So Efficiency ... . Boiling point is 1820°C 9. Specific gravity is 2.7 10. High resistance to corrosion. 

Explain with neat sketch the working principle of MIG.

Description : Explain with neat sketch the working principle of MIG.

Last Answer : In metal-arc inert gas welding the Weld area is shielded by an effectively inert atmosphere of argon, helium, carbon dioxide, or various other gas mixtures . The consumable bare Wire is fed automatically ... of the molten-weld puddle. Multiple-weld layers can be deposited at the joint. 

Explain any four properties of Moulding sand.

Description : Explain any four properties of Moulding sand. 

Last Answer : 1. Porosity: Molten metal always contain a certain amount of dissolved gases, which are evolved when the metal freezes the molten metal coming in contact with the moist sand , generates steam or ... to the casting. Refractoriness is measured by the sinter point of the sand rather than its melting

Define armature reaction in an alternator. Explain the effect of armature reaction at various P.F. of loads of alternator.

Description : Define armature reaction in an alternator. Explain the effect of armature reaction at various P.F. of loads of alternator.

Last Answer : Armature Reaction: The effect of armature flux on main flux is called as armature reaction.  Armature Reaction at Various Power Factors: When armature is loaded, the armature flux modifies ... lagging p.f. For capacitive loads the effect of flux is partly distorting and partly strengthening.

Explain the activities carried out during weekly maintenance of 3 ph. Induction motor.

Description : Explain the activities carried out during weekly maintenance of 3 ph. Induction motor. 

Last Answer : Activities Carried out During Weekly Maintenance of 3 ph. Induction Motor:  1) Check belt tension. In cases where this is excessive it should immediately be reduces and in the case of sleeve ... and cooled by oil mist systems its important to check the oil mist flow paths/pressure components.

Explain construction and working of AC servomotor.

Description : Explain construction and working of AC servomotor.

Last Answer : Construction of AC Servo Motor: AC servo motor is mainly composed of a stator and a rotor. Laminated stator core is usually made of silicon steel. Two phase windings are placed in the stator slots at 90 degree ... on rotor. Due to the force or torque acting on the rotor, it is set in motion. 

Explain the lighting scheme to be designed for each of the following: i) Special ward in hospitals ii) Dentist’s Cabin

Description : Explain the lighting scheme to be designed for each of the following: i) Special ward in hospitals ii) Dentist’s Cabin 

Last Answer : i) Special ward in hospital: For the patients in the wards, lighting should create a cozy and pleasant atmosphere. Lighting in the wards should be planned in such a way that it meets the specific ... we use such as cements and bonding agents that we use to restore your teeth back to health.

Explain the working of Neon sign tube with diagram.

Description : Explain the working of Neon sign tube with diagram.

Last Answer : Neon sign tube: The construction & circuit diagram for neon tube is as shown in fig. Basically neon tube is used for advertisement or decoration purpose. The maximum length of tube is ... the HT transformer must be earthed separately. * Caution notice of danger board is required.

Explain the working of HPMV Lamp with neat diagram.

Description : Explain the working of HPMV Lamp with neat diagram.

Last Answer : High-pressure Mercury-Vapour Lamp (HPMVL):  Working:  * Whenever 1-ph, 230V, AC Supply is provided to the discharge tube of MVL, initially the current flows from Phase to the choke to ... : The function of power factor improvement capacitor is to improve the power factor from 0.5 to 0.95.

Explain the features of Aquarium lighting.

Description : Explain the features of Aquarium lighting. 

Last Answer : 1) The aquarium light depends upon the size of the aquarium tank (Length, width and depth)  2) The aquarium lighting depends upon the all surrounding condition e.g. colour and size of the given ... The aquarium lighting should be economical.  9) The life of the aquarium lighting should be long. 

How to choose a metal detector?

Description : How to choose a metal detector?

Last Answer : How to choose a metal detector? Before you arm yourself with a metal detector, you need to decide what exactly needs to be found and where. A metal detector (aka metal detector) is a device ... metal detector, after you gain experience with this device, you can move on to more professional models.

In a Schering bridge the potential of the detector above earth potential is?

Last Answer : In a Schering bridge the potential of the detector above earth potential is a few volts only.

What do you mean by active filter? State its advantages over passive filter . Define pass band & stop band with respect to filter.

Description : What do you mean by active filter? State its advantages over passive filter . Define pass band & stop band with respect to filter.

Last Answer : Active Filter: Active Filter is formed by using active element along with the passive components.  Advantages of Active filter over Passive filter: High value of pass band gain can be obtained. It is ... pass band.  Stop Band Filter: The frequency range which is attenuated is known as stop band.

Define Multivibrator. State the types of multivibrator. Which M/V can be used as a flip-flop? Draw the circuit diagram.

Description : Define Multivibrator. State the types of multivibrator. Which M/V can be used as a flip-flop? Draw the circuit diagram.

Last Answer : Definition:- A multivibrator is an electronic circuit that switches rapidly by means of positive feedback between two or more states.  OR  A multivibrator is an electronic circuit used to implement a ... Bistable Multivibrator: it can operate as a flip-flop, Circuit diagram 

Draw and explain integrated duration curve used in system operation.

Description : Draw and explain integrated duration curve used in system operation. 

Last Answer : Diagram of integrated duration curve used in system operation: Explanation:  Integrated duration curve is obtained from load duration curve. It is drawn in between load on Y-axis in KW/MW and the X- ... a particular time of a day can also be shown on a curve which is called as mass curve. 

Draw diagram of class A push-pull amplifier and explain its operation.

Description : Draw diagram of class A push-pull amplifier and explain its operation. 

Last Answer : Class A Push-pull Amplifier: The circuit diagram of class A push-pull amplifier is as shown in the fig.(a). Operation: The resistors R1 and R2 along with Vcc provide the dc biasing so as ... Vcc is applied to the collectors of transistors Q1 and Q2 through the centretapped output transformer. 

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

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.

An additional condition for parallel operation of three-phase transformers over single-phase transformers is that

Description : An additional condition for parallel operation of three-phase transformers over single-phase transformers is that

Last Answer : An additional condition for parallel operation of three-phase transformers over single-phase transformers is that the transformers should belong to the same vector group

Which of the following is not a greenhouse gas ? a) CFCs b) SO2 c) PFC d) SF6

Description : Which of the following is not a greenhouse gas ? a) CFCs b) SO2 c) PFC d) SF6

Last Answer : b) SO2

Define safety planning for industry.

Description : Define safety planning for industry. 

Last Answer : Safety planning: It is the first step of safety management where in a safety manager decides in advance safety objectives, policy, procedure, strategies, rules, programmes, method, budget, ... facts and anticipating foreseeable events that may affect safety of plant, people and environment. 

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

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. 

Explain the operation of UPS with a neat block diagram.

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.

Explain the operation of advanced gas cooled reactor.

Description : Explain the operation of advanced gas cooled reactor.

Last Answer : Operation:- Carbon dioxide or Helium is the gas used for transferring the heat produced form the reactor core to the Heat exchanger. The gas is pumped through the reactor core at high pressure. In heat ... The AGR was designed to have a high thermal efficiency 40 %. Steam pressure is 162 Kg/cm2 

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

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.  

explain the parallel operation of IGBT?

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.

In a 3-phase converter circuit during commutation when one SCR in one phase is turned on to turn-off an SCR

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

List the different errors in wattmeter & explain compensation for it.

Description : List the different errors in wattmeter & explain compensation for it.

Last Answer : Errors in Wattmeter Compensation method Error due to connection method To overcome this error, wattmeters are provided with additional compensating winding which is connected in series with ... due to friction The weight of moving system be reduced to minimum possible.

Draw single phase full wave mid-point converter for inductive load. Draw input and output waveforms for it.

Description : Draw single phase full wave mid-point converter for inductive load. Draw input and output waveforms for it. 

Last Answer : Circuit Diagram: Waveforms:

What is Phase sequence? Draw waveforms of 3 phase emf.

Description : What is Phase sequence? Draw waveforms of 3 phase emf.

Last Answer : Phase sequence: It is the order in which the three phases reach their peak or maximum values. It is shown in below fig. the phase sequence is A-B-C (or R-Y-B). In the following waveforms, it is ... 120º, B- phase voltage attains its positive maximum value. So the phase sequence is R-Y-B.