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 ...
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 ...
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 ...
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 ...
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 ...
Capacitors
A capacitor is an electronic component that can store electric charge. A capacitor is constructed with two conductive plates separated by an insulator called a dielectric. More ...
Integrated Circuit Manufacturing BiCMOS Technology
BiCMOS is a technology that combines both CMOS and bipolar device structures in a single IC. The reason to combine these two different technologies is to create an IC chip that has the advantages of both CMOS and bipolar devices. More ...
Transforming Sources for Circuit Analysis
Kirchhoff's laws and Ohm's laws can get pretty laborious when you're analyzing complex circuits. Through a transformation technique, you modify a complex circuit so that in the transformed circuit, the devices are all connected in series or in parallel. After the transformation, you no longer need to systematically apply Kirchhoff's laws. More ...
Superposition Theorem
The resistive networks that satisfy Ohm's law allow a number of simplifying approaches to be taken in their analysis. Circuit analysis by superposition replaces all voltage sources but one with short circuits, then using the summation rules of series-parallel combinations of resistors determine the voltage across and current in each branch due to the remaining voltage source, and then repeating this process for all voltage sources and superposing the results. 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 ...
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 ...
Integrated Circuit Manufacturing Packaging
Before ICs can be put to their intended use they must be packaged. The package is responsible for interconnecting, powering, cooling, and protecting the IC. More ...
Transformers
Transformers work according to the principle of electromagnetic induction. If the first coil carries sine-wave ac of a certain frequency, then the induced current will be sine-wave ac of the same frequency in the second coil. 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 ...
