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 ...
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 ...
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 ...
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 ...
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 ...
Electrical Charge
The forces between electrically charged particles are used in technologies such as printers, pollution filters, and spray guns used for painting cars and trucks. Static electricity is the study of phenomena that involve an imbalance of electrical charge. Although creating this imbalance typically requires moving charge around, once the imbalance is created, it often remains static for a long time. 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 ...
Modern Semiconductor Manufacturing
The modern semiconductor manufacturing process sequence is the most sophisticated and unforgiving volume production technology that has ever been practiced successfully. It consists of a complex series of hundreds of unit process steps that must be performed very nearly flawlessly. More ...
Integrated Circuit Manufacturing CMOS Technology
The MOSFET (metal-oxide-semiconductor field-effect transistor) is the dominant device used in modern integrated circuits because it can be scaled to smaller dimensions than other types of devices. 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 ...
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 ...
Lithium Ion Battery Chemistry
Lithium-ion (Li-ion) batteries are one of the most common portable power sources used today. Impurities in the materials used to construct a lithium battery can cause it to overheat. More ...
Integrated Circuit Manufacturing Etching
photolithography is the process of transferring patterns to photoresist covering the surface of a semiconductor wafer. To produce circuit features, these resist patterns must be transferred into the underlying layers of the device. Pattern transfer is accomplished by an etching process that selectively removes unmasked portions of a layer. More ...
Integrated Circuit Manufacturing Deposition
Many different types of thin films are used to manufacture integrated circuits, including thermal oxides, dielectric layers, epitaxial layers, polycrystalline silicon, and metal films. This article addresses two techniques for depositing such films. More ...
