Electrical4U 
A zener diode is a diode designed to operate in reverse bias and hold a constant voltage across its terminals once its reverse voltage reaches the zener level. Circuits use that behaviour mainly for voltage regulation, meter protection and wave shaping. What is a Zener Diode? A zener diode is a diode whose specified reverse … Read more
Work function is the minimum energy needed to take an electron at a surface’s Fermi level to the vacuum immediately outside that surface. This surface property helps explain thermionic emission, photoemission, electronic contacts and field emission. This article defines the quantity, shows the ideal photoelectric equations and explains why surface preparation matters when using measured … Read more
What is an Op-Amp Integrator? An op-amp integrator is an inverting operational amplifier (op-amp) circuit whose feedback element is a capacitor. Within the circuit’s linear range, its output voltage equals a scaled, inverted time integral of the input voltage. A constant positive input therefore produces a negative-going output ramp. The scale factor is set by … Read more
Hospital lighting shapes the well-being and performance of patients, staff and visitors. Every space needs light matched to its task, from restful patient rooms to precision operating theatres, while energy use stays under control. Getting that balance right means understanding the purpose of hospital lighting, its recommended illuminance levels, the luminaire types available and proven … Read more
Low resistivity materials are defined as materials that allow electric current to flow easily. They matter throughout electrical engineering, building machines, equipment and devices. They also serve as conductors in various windings and in the transmission and distribution of electrical energy. Properties of Low Resistivity or High Conductivity Materials The following properties are desirable in … Read more
A xenon arc lamp is a gas discharge lamp that produces light by passing electricity through ionized xenon gas at high pressure. The arc emits a continuous spectrum from around 185 nm in the ultraviolet to about 2000 nm in the near infrared, so the bright white output looks remarkably like natural sunlight. That quality … Read more
A sinusoidal wave signal varies as a sine or cosine function. A time sinusoid repeats at one frequency and is described by its amplitude and phase. A travelling sinusoidal wave also has a wavelength and propagation speed. Sinusoids are useful because linear time-invariant systems respond to each frequency independently and Fourier methods represent suitable signals … Read more
A voltage source sets a specified electric potential difference across its terminals. A current source sets a specified electric current through its branch. The current drawn from a voltage source and the voltage across a current source depend on the rest of the circuit. Sources are classified as independent or dependent according to what sets … Read more
Magnetic permeability measures how easily a material magnetizes in an external magnetic field and how much magnetic flux it can carry as a result. This page covers the definition, formula, units, material types and the factors that change permeability. What is Magnetic Permeability? Magnetic permeability is the ratio of the magnetic flux density (B) to … Read more
An electrical conductor is a material with mobile charge carriers and enough conductivity for a stated use. Metals such as copper, aluminium, silver and gold conduct through electrons. Electrolytes conduct through ions, while semiconductors can use electrons and holes. A wire’s resistance also depends on its length and cross-sectional area. When an electric field acts … Read more