ABSTRACT
An electric power is the product of voltage (V) and current (I). Let the phase difference between voltage and current be Ø. Electric power is classified into (i) apparent power, (ii) active power, and (iii) reactive power. Apparent power is defined as voltage-to-current (V/I), active power is defined as VIcosØ, and reactive power is defined as VIsinØ. In the early days, analog watt meters were used, but nowadays digital watt meters replace analog watt meters because of accuracy, compactness, cost, etc. All digital watt meters use analog multipliers to multiply voltage and current signals and display in a display device. In this chapter, we will see how function circuits are used to measure power and power factor.
