Before the modern digital technology we use in computers today, electronic computations were conducted by utilizing both voltages and currents as representations of numerical values. This process needed circuitry capable of carrying out a wide range of analog signal processing tasks, which led to the use of operational amplifiers (often referred to as op-amps). The engineering concept of negative feedback, which forms the basis of practically all automatic control procedures, holds the key to the utility of these tiny circuits.
Ever since the first generators, harmonics have been a part of power systems. However, we now live in an era of power that is defined by non-linear loads. Equipment for powering computers, electronic ballasts, and VFDs are among the electronic power supplies that are used now more than ever. Unchecked harmonic distortion in these electrical equipment systems can result in damage and hazards such as overheating. Not only does this affect power quality, but it can become costly to fix. The question then becomes: do you know how to correctly measure the waveforms of your equipment while taking harmonic distortion into account?
Kirchhoff’s Current and Voltage Laws are at the center of circuit analysis. With them, we have the fundamental tool set we need to start studying circuits and the formulas for individual components such as resistors, capacitors, and inductors. Named after German physicist Gustav Kirchhoff (1824-1887), Kirchhoff’s Laws are electromagnetic approximations derived from Maxwell’s Equations. Simply put, they are applicable when the size of the components in a circuit are substantially smaller than the wavelength of the signals traveling through the circuit.
Ohm’s Law, discovered by Georg Simon Ohm and first published in 1827, is the earliest and arguably most important connection between current, voltage, and resistance. A straightforward and practical technique for studying electric circuits, Ohm’s Law is very commonly used and has been documented on a broad range of scales. For aspiring electrical engineers studying the basics or for seasoned professionals looking to refresh their knowledge, this scientific law is worth having a deep understanding of.
With voltage measurements, the total resistance of the voltmeter must be considered. Reading an analog voltmeter scale is like reading an analog ammeter scale. Some multirange voltmeters have only one range marked on the scale and the scale reading must be multiplied by the range switch setting to acquire the accurate voltage reading. Other voltmeters have individual ranges on the scale for every setting of the range switch. When utilizing these meters, ensure that you read the set of values that corresponds to the range switch setting. Many digital meters also have range switches, but they may additionally have a special feature known as autoranging. This means you can either utilize the range switch or let the digital meter set the proper range by itself.