August 2015

Coils, inductors, and chokes are the names used to indicate a coil of wire. “Inductor” is preferred because inductors have inductance, a property that is utilized in many electrical circuits. FIXED INDUCTORS The simplest coil or inductor has an air core and is made by winding a wire in a series of loops, which may […]

The capacitor is used in many electric circuits in both electronics and in air conditioning and refrigeration circuits. Two types of capacitors are used in these circuits: fixed and variable. FIXED CAPACITORS The fixed capacitor is made for a certain value and is not adjustable. The fixed capacitor is divided into several groupings. It may

The resistor is the most widely used electrical and electronic device. Every radio, television set, and control circuit has a resistor or resistors. This component is used to provide resistance. It is designed to be used at a fixed value or as a variable-value device. FIXED RESISTORS The fixed resistor is the simpler of the

The five most important sources of electricity for technicians are chemical action, heat, light, pressure, and magnetism. 1) CHEMICAL ACTION In the electrical and electronics fields, battery is the backup source of electricity. Batteries produce electrical energy by a chemical action. 2) HEAT Heat can be used to free electrons from some metals and from

Unlike in square wave inverters the switches of PWM inverters are turned on and off at significantly higher frequencies than the fundamental frequency of the output voltage waveform. The typical pole voltage waveform of a PWM inverter is shown in below figure over one cycle of output voltage. In a three-phase inverter the other two

Pulse width modulated (PWM) inverters are among the most used power-electronic circuits in practical applications. These inverters are capable of producing ac voltages of variable magnitude as well as variable frequency. The quality of output voltage can also be greatly enhanced, when compared with those of square wave inverters. The PWM inverters are very commonly

In a single-phase ac circuit, instantaneous power to a load is of a pulsating nature. Even at unity power factor (i.e., when the voltage and the current are in phase with respect to each other), the instantaneous power is less than unity (i.e., when the voltage and the current are not in phase). The instantaneous