# Explain the principle of ON OFF control and phase control of AC voltage controller with suitable circuit and waveforms.

Explain the principle of ON-OFF control and phase control of AC voltage controller with suitable circuit and waveforms.

3.5k views

The integral cycle control (on-off control) and phase angle control are the two types of AC voltage controller.

The principle of ON-OFF control:

The on-off control is also called an integral cycle control. The on-off control is shown in the figure for single phase full wave AC voltage controller. To avoid the fluctuations at the output the turning on and off operation should be fast. The power semiconductor switches are used in integral cycle control. In integral cycle control, the switch is turned on for the certain number of complete cycle and the switch is turned off for the certain number of cycles. The integral cycle control is not very popular. Because it introduces sub-harmonics in line current. Integral cycle control is used for heating applications and speed control of AC motors.

Phase control of AC voltage controller:

Phase angle control is the type of AC voltage controller. The power flow can be control by firing angle control. In phase control, the switch is on for some period of each cycle.

On off ac voltage controller with rl load

## Related Questions

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

185 views 0 answers

Explain the pulse width modulation technique for control of AC output voltage.

101 views 0 answers

Explain three phase half wave controller or three phase unidirectional controller.
Last Answer : Three phase half wave controller or unidirectional controller:

239 views 1 answer

Explain Three Phase Bidirectional Delta Connected Controller.
Last Answer : Three Phase Bidirectional Delta Connected Controller:

483 views 1 answer

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.

266 views 1 answer

Explain the need and steps to conduct the reduced voltage running up test on the three phase induction motor.

207 views 0 answers

Draw the waveform of three phase AC supply voltage.

212 views 0 answers

Explain series switching control of AC load. Single phase resistance load - Integral half cycle control Phase control - Resistance load

65 views 0 answers

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.

102 views 1 answer

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).

1.7k views 1 answer

What is a phase control thyristor?

153 views 0 answers

Explain the procedure to perform Short Circuit test on single phase transformer with circuit diagram.

111 views 0 answers

Explain with neat circuit diagrams the procedures to perform no load and blocked rotor tests on three phase induction motor.

127 views 0 answers

Define pinch off voltage and drain resistance of FET.
Last Answer : 1 . Pinch-off Voltage: It is the value of the drain to source voltage VDS at which the drain current ID reaches its constant saturation value. Any further increase in VDS does not have any ... drain to source voltage to the change in drain current. It is also called AC/dynamic drain resistance.

120 views 1 answer

What is meant by pinch off voltage in MOSFET?

102 views 0 answers

Explain power in single phase AC circuit.

82 views 0 answers

The speed of a three-phase induction motor is controlled by variable voltage variable frequency control (i.e. keeping V/f constant). As the frequency is reduced, the slip at maximum torque  (1) Decreases (2) Increases (3) Remains constant (4) None of the above
Last Answer : The speed of a three-phase induction motor is controlled by variable voltage variable frequency control (i.e. keeping V/f constant). As the frequency is reduced, the slip at maximum torque Increases

227 views 1 answer

speed control methods of three phase induction motor?
Last Answer : Speed control of three phase induction motor

363 views 2 answers

Write short notes on 3 phase AC system.

120 views 0 answers

An unshielded moving iron voltmeter is used to measure the voltage in an AC circuit. The stray DC magnetic field having a component along the axis will be  (1) unaffected (2) decreased (3) increased (4) either decreased or increased depending on the direction of the DC field
Last Answer : An unshielded moving iron voltmeter is used to measure the voltage in an AC circuit. The stray DC magnetic field having a component along the axis will be either decreased or increased depending on the direction of the DC field

334 views 1 answer

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.

412 views 1 answer

Last Answer : The armature voltage control of D.C. motor provides constant torque drive.

91 views 1 answer

What is the difference between a line voltage and low voltage control system?

117 views 0 answers

Explain how sinusoidal AC voltage is generated by using simple one loop generator.
Last Answer : An electric current produced by means of electrical machine is known as generator which converts mechanical energy into electrical energy. When conductor cuts the magnetic flux, emf induced in it. (Faraday' ... upon position of armature. The nature of emf is alternating as shown by the waveform.

1.4k views 1 answer

Analyze the effect of supply voltage on performance of LED as regards current, Lumen output, efficacy and life.
Last Answer : 1) Effect on Current:- In LED current depends upon supply voltage, if voltage get changes then current also change but this change in current will be control by resistors which are connected in series.  2) ...   4) Effect on Life:- If supply voltage is not stable then life of LED get reduced.

106 views 1 answer

With the help of N-channel JFET describe the effect of input voltage VGS on output current ID.
Last Answer : Working of N channel FET: * When a voltage is applied between the drain and source with a DC supply (VDD), the electrons flows from source to drain through narrow channel ... where the channel gets completely blocked and the drain current becomes zero is called pinch- off voltage.

224 views 1 answer

what is the minimum voltage required to turn on a diode ?
Last Answer : 0.7 v sil and 0.3 v for gr

156 views 1 answer

Draw single phase full wave mid-point converter for inductive load. Draw input and output waveforms for it.
Last Answer : Circuit Diagram: Waveforms:

531 views 1 answer

For a balanced three phase star connected load for which line voltage is 230V and per phase resistance and reactance is 6 Ohm and 8 Ohm respectively. Calculate: 1) phase voltage 2) line current 3) power factor 4) total power absorbed

203 views 0 answers

Write the relation between phase and line current, phase and line voltage for Star connection.
Last Answer : Line voltage is equal to root three times of phase voltage and line and phase currents are equal in star connection

374 views 2 answers

What is line voltage and phase voltage? Draw balanced three phase star connected system. Show all the voltages and currents.

125 views 0 answers

A single core cable is designed to work for a single phase system with a peak voltage of 220 kV. The maximum permissible stress in the dielectric is not to exceed 20 kV/mm. For economical size, the overall core diameter of the cable is (A) 28.2 mm (B) 26.4 mm (C) 24.4 mm (D) 22.0 mm
Last Answer : A single core cable is designed to work for a single phase system with a peak voltage of 220 kV. The maximum permissible stress in the dielectric is not to exceed 20 kV/mm. For economical size, the overall core diameter of the cable is 22.0 mm

755 views 1 answer

In an alternator at lagging power factor the generated voltage per phase as compared to that at unity power factor?
Last Answer : In an alternator, at lagging power factor the generated voltage per phase as compared to that at unity power factor must be more than terminal voltage.

524 views 1 answer

What is the difference between line and phase voltage?
Last Answer : Line voltage  is  voltage  between two  phases R &Y  (415 v)  while  phase  voltage  is  the  voltage  between  one  phase and  a neutral  B &  N   (240 v).

207 views 1 answer

Why the read of 3 phase voltage is 440?
Last Answer : The  read  of  a  phase  voltage  should be approximatly  240v. This  is  because  line  voltage  equals  to quberoot of  phase  voltage.

96 views 1 answer

What is the voltage in 3 phase line?
Last Answer : between 430 to 440 v

283 views 4 answers

Total instantaneous power supplied by a 3-phase ac supply to a balanced R-L load is
Last Answer : Total instantaneous power supplied by a 3-phase ac supply to a balanced R-L load is constant

1.3k views 1 answer

Is the power line voltage available in our homes a dc or an ac voltage?
Last Answer : The power line voltage available in our homes is AC. Mobile dwellings are the most commonly DC-supplied homes and even then they tend to include AC supply for heavier loads.

5.2k views 1 answer

A Unified Power Flow Controller (FACTS controller) is a voltage source converter based (A) Inter-phase power controller (B) Static Compensator (C) Combination of series and shunt compensators (D) Solid-state series compensator
Last Answer : A Unified Power Flow Controller (FACTS controller) is a voltage source converter based Combination of series and shunt compensators

110 views 1 answer

The voltage of the single phase supply to residential consumers is (a) 110 V (b) 210 V (c) 230 V (d) 400 V
Last Answer : (c) 230 V

14 views 1 answer

Last Answer : The stator of phase shifting transformer for use in conjunction with an A.C. potentiometer usually has a two-phase winding.

173 views 1 answer

Constant voltage transmission entails the following disadvantage (a) large conductor area is required for same power transmission (b) short-circuit current of the system is increased (c) either of the above (d) none of the above
Last Answer : (b) short-circuit current of the system is increased

12 views 1 answer

Which of the following is the demerit of a 'constant voltage transmission system' ? (a) Increase of short-circuit current of the system (b) Availability of steady voltage at all loads at ... of carrying increased power for a given conductor size in case of long-distance heavy power transmission
Last Answer : (a) Increase of short-circuit current of the system

19 views 1 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
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

241 views 1 answer

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

924 views 1 answer

In AC.S.R. conductors, the insulation between aluminium and steel conductors is (a) insulin (b) bitumen (c) varnish (d) no insulation is required
Last Answer : (d) no insulation is required

9 views 1 answer

Draw and explain pneumatic proportional controller.
Last Answer : Explanation : Basic : Proportional control is one in which the process input is change in direct proportion to the error(t) controls the output so that the manipulated variable and the error has proportional relation. ... the MV and SP reference value called as error Given as :  Error = SP - MV

120 views 1 answer

Last Answer : Keypad Controller: It's a device which interfaces between the computer and keyboard. That is a input device and used for transfer the data to connected device.

305 views 2 answers

What is the purpose of auxiliary controller in substation?
Last Answer : The systems of substation auxiliaries ensure operation of substations providing internal consumers of substations with operating direct and alternating currents. Any breakdown (loss) of auxiliary systems ... whole substation, as well as serious problems during its subsequent putting into operation.

93 views 1 answer

Define Integral controller. State their advantages
Last Answer : Advantages of integral control action: 1) Improves steady state response 2) Removes offset error in the process variable. 3) Eliminates steady state error