Electromagnetic Devices
Electromagnetic devices work based on the relationship between electrical current and a magnetic field. They are used to control valves, cooling and heating systems, relays, and electric motors. More ...
Inductors in Series and Parallel
With inductors connected in series, the total inductance is the sum of the inductances of the individual inductors With inductors in parallel, the reciprocal of the equivalent inductance is the sum of the reciprocals of the inductors connected in parallel. More ...
Silicon Controlled Rectifier (SCR)
A Silicon Controlled Rectifier (SCR) is a 4-layer diode that is controlled by a gate signal. It ca be turned on by a pulse on the gate. More ...
Magnetism Permeability and Retentivity
Permeability is a property of a material that describes the ease with which magnetic flux is established in the material. Retentivity is a materials ability to retain a certain amount of residual magnetism after the magnetizing force is removed. More ...
Magnetism
Electric currents and magnetic fields are closely related. Whenever an electric current flows a magnetic field accompanies the current. When a wire is coiled up, the resulting magnetic flux becomes more concentrated. More ...
Lead-Acid Battery Chemistry
As a lead-acid battery is repeatedly recharged, sulfation will build-up on the plates and the battery will begin to loose its capacity to restore to a full charge and eventually must be replaced. More ...
Phase shift in AC Circuits
In an AC circuit with a capacitor or an inductor there is a phase shift between voltage and current. In this article you learn how to calculate the amount of that phase shift. More ...
Electrical Transformers
A transformer is an electrical device that uses the principle of magnetic induction to step voltage up or step down. Inversely it increases or decreases the current available at the different voltages. More ...
Alternating Current
With DC (Direct Current), electric current flows in only one direction. With AC (Alternating Current), current direction reverses periodically. More ...
RC Filters
An RC filter can accept input sinewave signals and block certain bands of frquencies, thus allowing to pass only desired frquencies. This section describes passive RC filters. A passive RC filter uses only resistors and capacitors. More ...
Inductor Mutual Inductance and Coefficient of Coupling
Mutual Inductance the property of a coil in which it opposes the change of current in another coil. The coefficient of coupling between two coils is the fraction of magnetic flux produced by the current in one coil that links with the other coil. More ...
Integrated Circuit Manufacturing Impurity Doping
Impurity doping is the introduction of controlled amounts of impurities into semiconductors to change their electrical properties. Diffusion and ion implantation are the two key methods of impurity doping. More ...
Common Emitter Configuration Transistor Biasing
To design a common emitter amplifier circuit, use a voltage divider with resistors selected to set the base voltage at the center of the transistor's linear region. Then, through a DC blocking capacitor, apply a waveform to the transistor's base. More ...
Integrated Circuit Photoresist Process
The semiconductor photolithography process involves coating the substrate with A light-sensitive chemical layer called photoresist. Light is projected through a mask onto the substrate causings photoresists to react chemically. More ...

