Working Principle of Automatic Voltage Regulator: The working of an AVR is as follows: Figure 2. Hardware Block Diagram Figure 3. Single Phase Auto Transformer The single Phase Autotransformer having only one winding; part of this winding is common to both primary and secondary. Primary and secondary windings are electrically isolated in two winding transformer, but this is not in the case of autotransformer. As AVR is nothing but automatic voltage regulator. If voltage is increases then AVR sense that voltage and compare that voltage with the reference voltage and produce error signal and these error signal send to servo motor through PWM signal by Arduino. Figure 5. Single Phase Step down Transformer Step Down Transformer: A Servo Motor has an output shaft. This shaft positioned to some angular positions by sending the servo a coded signal. As the signal exists on the input line, the servo will maintain the angular position of the shaft. The angular position of the shaft changes, If the signal changes. The main function of capacitor is for smoothing the wave of bridge rectifier. 470 micro farad capacitor is used here After that the output is given to variable potentiometer. The smoothing capacitor converts the rippled output of the rectifie: into a smooth DC voltage. The Full Bridge Rectifier is used for converting output voltage of step down transformer into 5 V DC. Then these supply pass to Arduino which s work on the 5 V supply and before passing these supply to Arduino it passed from Smoothing Capacitor for eliminating ripple in the supply. A potentiometer is a three-terminal rheostat with a rotating contact that forms an voltage divider. If there is only two terminals then one end and the wiper, it acts as a variable rheostat. The measuring instrument called a potentiometer is a voltage divider used for measuring voltage. Figure 11. Hardware Setup
