Page 96 - CITS - Electronic Mechanic - TT - 2024
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ELECTRONICS MECHANIC - CITS




           DC Voltage Stabilizers:
           Series or Shunt regulators are frequently used for regulating the voltage of the DC power supplies. A reference
           voltage is applied using a shunt regulator like Zener diode or Voltage regulator tube. These voltage stabilizing
           devices start conduction at a specified voltage and they will conduct maximum current to hold the specified
           terminal voltage. Excess current is diverted to ground often using a low-value resistor for dissipating the energy.
           The figure shows the DC-adjustable-voltage stabilizer using IC LM317.



















           The shunt regulator  output is used only for providing  the standard
           reference voltage to the electronic device called as voltage stabilizer,
           which  is capable  of delivering  much larger  currents based  on the
           demand.

           Automatic Voltage Stabilizers:
           These voltage  stabilizers are  used on generator sets,  emergency
           power supply, oil rigs, and so on. It is an electronic power device used
           for providing variable voltage and, this can be done without changing
           the power factor or phase shift. Large sized voltage stabilizers are
           fixed permanently on the distributed lines and small voltage stabilizers
           are used for  protection of  the  home appliances  from  the voltage
           fluctuations. If the voltage of the power supply is less than the required
           range, then a step up transformer is used for stepping up the voltage
           levels and similarly if the voltage is greater than the required range,
           then it is stepped-down using a step-down transformer.
           Practical example  of automatic voltage  stabilizer  can be observed  in power  supply  circuits used to provide
           supplies to the electronic and electronic circuits. Frequently 7805 regulator is used for providing supply to the
           microcontroller based project kits as the microcontrollers operate at 5v. In this 7805 voltage stabilizer, the first
           two digits represent the positive series and the last two digits represents the output voltage value of the voltage
           regulator.




























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                                    CITS : E & H - Electronics Mechanic - Lesson 48 - 55
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