Electrical Lectures
PLC Latch (Flip-Flop) Logic Function – Like a Sticky Switch!
More complex systems cannot be controlled with combinatorial logic alone. The main reason for this is that we cannot (or choose not to) add sensors to detect all conditions. In these cases we can use events to estimate the condition… Read more
Aug 24, 2015 | By Edvard Csanyi
Electrical Lectures
Kirchhoff’s Laws For Electrical Engineers – Beginners
Two extremely important principles in electric circuits were codified by Gustav Robert Kirchhoff in the year 1847, known as Kirchhoff’s Laws. His two laws refer to Voltages and Currents in electric circuits, respectively. Kirchhoff’s Voltage Law states that the algebraic… Read more
Aug 19, 2015 | By Edvard Csanyi
Electrical Lectures
Few advice for improving integrity of protective conductor
Most modern electronic equipment uses switched mode power supplies (SMPS) which draw pulses of current from the mains supply rather than a continuous sinusoidal current. The fast rise time edges of the current waveform contain high frequencies that can cause serious radio frequency… Read more
Aug 14, 2015 | By Edvard Csanyi
Electrical Lectures
Practical Considerations of Transformer Heat and Noise
In addition to unwanted electrical effects, transformers may also exhibit undesirable physical effects, the most notable being the production of heat and noise. Transformer noise is primarily a nuisance effect, but heat is a potentially serious problem because winding insulation… Read more
Jul 31, 2015 | By Edvard Csanyi
Electrical Lectures
Essential Basics of Total Harmonic Distortion (THD)
For a signal y, the total harmonic distortion (THD) is defined by the equation: This definition complies with that of standard IEC 61000-2-2. Note that the resulting value may exceed one. According to the standard, h can generally be limited to… Read more
Jul 22, 2015 | By Edvard Csanyi
Electrical Lectures
What can a PLC do? Why do we use them?
“PLC” means “Programmable Logic Controller”, that’s clear. The word “Programmable” differentiates it from the conventional hard-wired relay logic. It can be easily programmed or changed as per the application’s requirement. The PLC also surpassed the hazard of changing the wiring…. Read more
Jul 15, 2015 | By Edvard Csanyi
Electrical Lectures
4 Main Means For The Generation Of Reactive Power
The four main means for the generation of reactive power are: synchronous alternators, synchronous compensators (SC), static var compensators (SVC) and banks of static capacitors. Contents Synchronous alternators Synchronous compensators (SC) Static var compensators (SVC) and Banks of static capacitors… Read more
Jun 29, 2015 | By Edvard Csanyi
Electric Motor
Basics of DC Motors For Electrical Engineers – Beginners
Separate field excitation DC motors are still sometimes used for driving machines at variable speed. These motors are very easy to miniaturize, and essential for very low powers and low voltages. They are also particularly suitable, up to high power… Read more
Jun 15, 2015 | By Edvard Csanyi
Electrical Lectures
Cable sizing of sub-main electrical circuits (working examples)
A sub-main electrical circuit can be defined as a circuit connected directly from the main LV switchboard to a sub-main distribution panel or a rising main for final connection of the minor current-using equipment. The Code requires that the maximum copper loss in… Read more
Apr 29, 2015 | By Edvard Csanyi
Electrical Lectures
Back To School – Let’s Calculate Current I3
Referring to the following circuit, calculate direct current I3: Using Kirchhoff’s laws; Using nodal analysis; Applying Thévenin’s theorem at nodes A and B. – KCL stands for Kirchhoff’s Current Law – KVL stands for Kirchhoff’s Voltage Law The following equation… Read more
Apr 10, 2015 | By Edvard Csanyi
Electrical Lectures
Miniature Circuit Breakers (MCBs) For Beginners
This technical article focuses on the widely used miniature circuit breakers rated for 240 V or less. These are smaller and lower-rated versions of industrial-grade molded-case circuit breakers rated for 600 V or less. These miniature breakers, called air circuit… Read more
Jan 26, 2015 | By Edvard Csanyi
Electrical Lectures
The choice of system voltage according to ANSI standard C84.1
The selection of system voltages is crucial to successful power system design. Reference lists the standard voltages for the United States and their ranges. The nominal voltages are given in Table 1 below. As can be seen, ANSI C84.1-1989 divides system… Read more
Aug 20, 2014 | By Edvard Csanyi
Electrical Lectures
2 Most Common Contributing Factors In Motor Insulation Failure
The most frequent failure in electrical equipment is the degradation and breakdown (flashover) of the insulation. Electrical insulation can be liquid or solid, organic or inorganic. Organic insulation material consists of: enamels, varnishes, resins, or polymers that are applied to the steel surface to provide… Read more
Jun 25, 2014 | By Edvard Csanyi
Electrical Lectures
What is the short-circuit switching (making / breaking) capacity?
The switching capacity is the r.m.s value of a current at a given power factor cos φ as well as a given rated voltage at which a switchgear or a fuse can still shut-off under specified conditions in an operationally… Read more
Feb 10, 2014 | By Edvard Csanyi
Electrical Lectures
Important in role of capacitors in distribution systems
Should the voltage on a circuit fall below a specified level for some reason, a device called a capacitor can momentarily maintain the voltage at line value. Basically, a capacitor serves the same purpose as a storage tank in a… Read more
Nov 27, 2013 | By Edvard Csanyi
