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 ...
Planar Integrated Circuit Fabrication
The key unit process steps in IC fabrication, include oxidation, photolithography, etching, ion implantation, and metallization. Here, we describe the oxidation steps. 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 ...
Operational Amplifier
An operational amplifier (op amp) is an amplifier circuit with a differential input, in other words it amplifies the voltage difference between its two inputs. The open-loop gain of an op amp is typically very large so normally, it's configured with negative feedback to reduce the gain. 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 ...
Basic Laws and Analytical Methods for Circuit Analysis
Circuit analysis is like the psychoanalysis of the electrical engineering world because itâ?Ts all about studying the behavior of circuits. With any circuit, you have an input signal, such as a battery source or an audio signal. What you want to figure out is the circuitâ?Ts output â?" how the circuit responds to a given input. 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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
Batteries
Early in the history of electrical science, laboratory physicists found that when metals came into contact with certain chemical solutions, voltages appeared between the pieces of metal. These were the first electrochemical cells. More ...
