Sunday, 9 February 2020

What is Regulator? Its Advantages, Disadvantages, Applications


regulator is defined as to maintain a constant output.
A regulator may be a simple feed-forward design or may include negative feedback control loops. It may use an electromechanical mechanism, or electronic components. Depending on the design, it may be used to regulate one or more AC or DC voltages.
There are different types are available in regulators Pressure Regulator, Voltage regulator, Flow Regulator, Temperature Regulator, etc.

Need of Regulators:

  • Electronic 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.

Voltage regulator is most commonly used regulator which is explained below in short.
Voltage Regulators:
Circuit Diagram Of Voltage Regulator
Circuit Diagram Of Voltage Regulator

The circuit which reduces the variations in output DC voltage of an unregulated DC power supply is called as “voltage regulator”.
                        V.R. = VNL – VFL / VNL
                        % regulation = V.R. *100 %

Voltage Regulation factors:
1. Variations in output voltage due to IL :
  • The output voltage of an unregulated power supply reduces with increase in load current IL, due to the voltage drop across secondary resistance. When the voltage regulator is introduced, the output voltage is made to remain constant in spite of change in IL 

2.Input voltage Vin:
  • The output voltage of an unregulated power supply increases with increases in input voltage applied to the rectifier. The input voltage the regulator comes from unregulated power supply.

3. Temperature T:
  • The output voltage of an unregulated power supply changes with change in temperature because of characteristics of electronic devices used in rectifiers, filters & regulators are temperature dependent.

Line and Load Regulation:
  • Ideally, a power supply should deliver a constant output voltage regardless of any changes that take place in the input or output circuits.
  • In particular, the mains supply voltage, (the line voltage,) increases and decreases significantly depending on national factors such as demand (weather conditions, ‘Coronation Street’, FA Cup Final, ‘X Factor’ etc.) The output voltage of the power supply should ignore these changes. Line regulation measures how successfully the power supply does this.
  • Here is a useful definition of line regulation: Line regulation is a measure of the ability of the power supply to maintain a steady output voltage when the input line voltage changes”
  • It is expressed as the percentage change in the output voltage relative to the change in the input line voltage.
  • When the load attached to the output of a power supply is changed, the current through it changes, and this can cause a change in the power supply output voltage. 
  • When the power supply is used to deliver a steady voltage, it behaves as if there is an internal resistor in series with the load. When the output current, IOUT, increases, the voltage dropped across this internal resistor increases, and the output voltage, VOUT, seen by the load, decreases. 
  • Load regulation measures how successful the power supply is in ignoring changes in the load. 
  • Now a useful definition of load regulation: “Load regulation is a measure of the ability of the output voltage to remain constant when the output current changes due to a change in the load”.

Advantages of regulators

  • It should not requires regular maintenance
  • Output is good.
  • It gives good line isolation.
  • Less ripple and output terminals.
  • Good efficiency.
  • Low cost >

  Disadvantages of regulators 
  • Low efficiency if input output difference is large.
  • It may require a heat sink.
  • Capable exclusively of step-down operation.

Applications of regulators    
  • It is used in RF, Radio, Communication Devices. 
  • Medical Equipment.
  • Measuring devices.



Post a comment

Popular Posts