EMI, RFI, EMC, EMS, What's the Difference?
EMI, RFI, EMC, and EMS all refer to different aspects of radio frequency interference which may cause elecronic devices to malfunction. Correcting these problems can be an art and a science. More ...
Inductive Reactance
The opposition that the coil offers to ac is called inductive reactance. Like resistance, reactance is measured in ohms. Unlike resistance, reactance changes with frequency. And in an Inductor, the Voltage leads the Current by 90 degrees. 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 ...
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 ...
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 ...
Direct Current
The nucleus of an atom is relatively heavy, so electricity primarily involves the flow of electrons. The nucleus of an atom generally doesn't move much. More ...
Junction Field Effect Transistor (JFET)
A Junction Field Effect Transistor (JFET) consists of a channel and a pn junction. The gate controls the conductance of the channel. A JFET is a voltage controlled device, therefore no current flows into the gate. More ...
How to Read a Capacitor's Values
Due to the limited space available for printing, physically small capacitors are especially difficult to read. Therefore capacitors use a wide variety of codes to describe their characteristics. More ...
Inductors in DC Circuits
When voltage first applied current through an inductive circuit is low because a magnetic field starts building in the coil, and this magnetic field creates a back electromotive force (EMF) that oppose the current in the inductor. More ...
Inductors in Series and Parallel
Inductances in series add like resistances in series. The total value is the sum of the individual values. Inductances in parallel values add up like the values of resistors in parallel. The reciprocal of total inductance is the sum of reciprocals of all the individual inductances. More ...
The Diode
A diode is a semiconductor component designed to allow current to pass in one direction. To form a diode, a P type semiconductor is joined with an N type of the same semiconductor element, forming a P-N junction. Diodes are used for turning AC to DC, isolating signals, and mixing signals. More ...
How to Calculate Impedance
Impedance is one of the most difficult things the electronics technician student needs to calculate. To calculate impedance, you must know the value of all resistors and the impedance of all inductors and capacitors in the circuit. Then you can calculate impedance using a simple mathematical formula. More ...
Electronics Lab
Even though an electronic circuit may appear to work on paper, and maybe even in a circuit simulator, it's always important to test it in the real world. Prototype circuits can be built using a solderless breadboard. More ...
Electric Fields and Static Electricity
Static electricity is a phenomenon caused by a buildup of unbalanced electric charge that is not moving. We are all familiar with the static electric charge caused by dragging our feet across a carpet and then the sudden static discharge caused by grabbing a door knob. More ...
