Electrical4U 
A light-emitting diode (LED) is a forward-biased p-n junction diode designed so that electron-hole recombination releases useful light. The semiconductor band gap sets the photon-energy range, while the junction structure, package and drive current affect how much of that light leaves the device. Working of LED Forward bias lowers the p-n junction barrier and injects … Read more
Blood-gas analysers directly measure blood pH and the partial pressures of carbon dioxide and oxygen. An arterial pH below 7.35 indicates acidemia, while a value above 7.45 indicates alkalemia. The pH result alone does not show whether the cause is respiratory or metabolic. Interpretation also needs pCO2, bicarbonate, oxygen results and the clinical context, so … Read more
A printed circuit board (PCB), also called a printed wiring board, mechanically supports components and connects them through patterned copper conductors on an insulating base. Pads accept soldered component terminals, while plated holes and vias can connect conductors between layers. The manufactured board replaces much of the point-to-point wiring that would otherwise join the same … Read more
Luminous Efficacy Luminous efficacy tells you how much visible light a lamp emits for each watt of electric power it uses. It is luminous flux in lumens divided by power in watts, so the unit is lumens per watt (lm/W). A higher value means that the lamp produces more light for the same electrical input. … Read more
Introduction of Efficiency of Transformer Transformer efficiency is output power divided by input power at a stated load and power factor. Transformers lose part of their input energy as heat in the core, windings, insulation and surrounding metalwork. These losses affect temperature rise, cooling requirements and insulation life. Efficiency is high, with values around 98 … Read more
What is Eddy Current Eddy currents are circulating currents that form inside a conductor when a changing magnetic field cuts through the bulk. According to Lenz’s law, when a conducting loop is exposed to a changing magnetic field, it generates an emf that induces a current opposing the change. The same process in a solid … Read more
Cold rolled grain oriented (CRGO) silicon steel is electrical steel with grains aligned so magnetisation is easiest along the rolling direction. Adding silicon (Si) to iron (Fe) in controlled amounts raises resistivity, cuts eddy-current loss, raises magnetic permeability and lowers magnetostriction. Silicon steel of this kind dates from the late 19th century. The table below … Read more
This Zener diode experiment finds the reverse breakdown voltage by raising bias in steps and plotting current against voltage. The Zener diode is used as Zener diodes for voltage regulation and voltage stabilisation because, once reverse bias reaches the Zener breakdown voltage, the voltage across the device stays near that level while current rises. Below … Read more
What are Z Parameters? Z parameters, also called impedance parameters, are important in electrical engineering for describing how linear networks behave electrically. They are employed within Z matrices to determine the voltages and currents entering and leaving a network. Z-parameters are also known as “open-circuit impedance parameters”, as they are calculated under open-circuit conditions. That … Read more
What are Active and Passive Circuit Elements (Components)? Active and passive components form the two main types of electronic circuit elements. An active component supplies energy to an electric circuit, and hence has the ability to electrically control the flow of charge. A passive component can only receive energy, which it can either dissipate or … Read more