TUHIN GHOSH

 A PROJECT ON VOLTAGE CONTROL

 

The given project is successfully running and the circuit diagram given is 100% accurate.

Circuit Diagram:

Introduction:

qA voltage stabilizer is also called Automatic Voltage Stabilizer or AC Voltage Stabilizer or Voltage Regulator.

qActually an automatic voltage stabilizer is designed to automatically maintain a constant voltage level, with protections of equipment against voltage surges, over voltage, under voltage, smoothing impulsive noise.

qIt regulates the fluctuating input voltage and produces an constant  output voltage. The fluctuating range in different countries differs a lot. So, if our countries suffer from unstable voltage, we must equip voltage stabilizers for our appliances or a big AVR for our whole house .

qElectronic voltage regulators are found in devices such as computer power supplies where they stabilize the DC voltages used by the processor and other elements. In automobile alternators and central power station generator plants, voltage regulators control the output of the plant. In an electric power distribution system, voltage regulators may be installed at a substation or along distribution lines so that all customers receive steady voltage independent of how much power is drawn from the line.

Working Principle:
When the mains voltage is between 170V and 205V, the voltage is trigger inputs (pins 6 and 8) is less than 4.5 V and hence both the timers are set.

At this instance both relays are in de-energized position and both secondaries 1 and 2 of the transformer are in series with the mains supply. Only the BOOST LED is turned on.
  When the mains input voltage is increased to 250V the voltage at threshold input (pin 2) reaches 9V and timer 1 is reset, relay RL1 is energized and mains voltage appears at the output of the stabilizer. Only the normal led lights up.

When the input voltage is increased to 240V the voltage at threshold input (pin 13) reaches 9V and timer 2 resets.
Relay RL2 is energized and secondary 2 is switched in series-opposition with the mains supply and only the buck led glows.

When the input is decreased to 235V the voltage at trigger input(pin 8)reaches 4.5V timer 2 is set and relay RL2 is de-energised. when the input is reduced to 200V the voltage at trigger input (pin 6)reaches 4.5V and timer 1 is set, de-energizing RL1.

Project Objective:

ØThe purpose of  our project is to keep the voltage in a circuit relatively close to a desired value.

ØVoltage regulators are one of the most common electronic components, since a power supply frequently produces fluctuating voltage that would otherwise damage one of the components in the circuit. Voltage regulators have a variety of specific functions, depending on their particular application.

ØAC voltage stabilization refers to the regulation of relatively minor fluctuations in AC voltage.

ØThese voltage regulators are routinely used in a home to keep the voltage within the range needed by household appliances.

ØAC voltage regulators use a servomechanism that continually responds to minute changes in the transformer's voltage to keep the house voltage within a narrow range.

Advantages:

Ø Output voltage regulation is good

ØUltrafast voltage correction speed

ØVery low or no regular maintenance

ØGood line isolation

Disadvantages:

 

Ø Poor current overload capacity (except the series transformer design)

ØMore expensive than mechanical voltage regulators