An amplifier, electronic amplifier or (informally) amp is an electronic device that can increase the magnitude of a signal. It is a two-port electronic circuit that uses electric power from a power supply to increase the amplitude of a signal applied to its input terminals, producing a proportionally greater amplitude signal at its output. The amount of amplification provided by an amplifier is measured by its gain: the ratio of output voltage, current, or power to input. An amplifier is defined as a circuit that has a power gain greater than one.
Pulse-width modulation (PWM), also known as pulse-duration modulation (PDM) or pulse-length modulation (PLM), is any method of representing a signal as a rectangular wave with a varying duty cycle.
A power inverter, inverter, or invertor is a power electronic device or circuitry that changes direct current (DC) to alternating current (AC). The resulting AC frequency obtained depends on the particular device employed. Inverters do the opposite of rectifiers which were originally large electromechanical devices converting AC to DC.
A switched-mode power supply (SMPS), also called switching-mode power supply, switch-mode power supply, switched power supply, or simply switcher, is an electronic power supply that incorporates a switching regulator to convert electrical power efficiently.
This is an index of articles relating to electronics and electricity or natural electricity and things that run on electricity and things that use or conduct electricity.
Power electronics is the application of electronics to the control and conversion of electric power.
A mixed-signal integrated circuit is any integrated circuit that has both analog circuits and digital circuits on a single semiconductor die. Their usage has grown dramatically with the increased use of cell phones, telecommunications, portable electronics, and automobiles with electronics and digital sensors.
In electronics, a chopper circuit is any of numerous types of electronic switching devices and circuits used in power control and signal applications. A chopper is a device that converts fixed DC input to a variable DC output voltage directly. Essentially, a chopper is an electronic switch that is used to interrupt one signal under the control of another.
A variable-frequency drive is a type of AC motor drive that controls speed and torque by varying the frequency of the input electricity. Depending on its topology, it controls the associated voltage or current variation.
A class-D amplifier or switching amplifier is an electronic amplifier in which the amplifying devices operate as electronic switches, and not as linear gain devices as in other amplifiers. They operate by rapidly switching back and forth between the supply rails, using pulse-width modulation, pulse-density modulation, or related techniques to produce a pulse train output. A simple low-pass filter may be used to attenuate their high-frequency content to provide analog output current and voltage. Little energy is dissipated in the amplifying transistors because they are always either fully on or fully off, so efficiency can exceed 90%.
A cycloconverter (CCV) or a cycloinverter converts a constant amplitude, constant frequency AC waveform to another AC waveform of a lower frequency by synthesizing the output waveform from segments of the AC supply without an intermediate DC link. There are two main types of CCVs, circulating current type or blocking mode type, most commercial high power products being of the blocking mode type.
This is an alphabetical list of articles pertaining specifically to electrical and electronics engineering. For a thematic list, please see List of electrical engineering topics. For a broad overview of engineering, see List of engineering topics. For biographies, see List of engineers.
John G. Webster was an American electrical engineer and a founding pioneer in the field of biomedical engineering. In 2008, Professor Webster was awarded the University of Wisconsin, College of Engineering, Polygon Engineering Council Outstanding Instructor Award. In 2019, the Institute of Electrical and Electronics Engineers awarded him its James H. Mulligan Jr. Educational Medal for his career contributions. Professor Webster died on March 29, 2023.
Space vector modulation (SVM) is an algorithm for the control of pulse-width modulation (PWM), invented by Gerhard Pfaff, Alois Weschta, and Albert Wick in 1982. It is used for the creation of alternating current (AC) waveforms; most commonly to drive 3 phase AC powered motors at varying speeds from DC using multiple class-D amplifiers. There are variations of SVM that result in different quality and computational requirements. One active area of development is in the reduction of total harmonic distortion (THD) created by the rapid switching inherent to these algorithms.
An HVDC converter converts electric power from high voltage alternating current (AC) to high-voltage direct current (HVDC), or vice versa. HVDC is used as an alternative to AC for transmitting electrical energy over long distances or between AC power systems of different frequencies. HVDC converters capable of converting up to two gigawatts (GW) and with voltage ratings of up to 900 kilovolts (kV) have been built, and even higher ratings are technically feasible. A complete converter station may contain several such converters in series and/or parallel to achieve total system DC voltage ratings of up to 1,100 kV.
In electronics, power amplifier classes are letter symbols applied to different power amplifier types. The class gives a broad indication of an amplifier's characteristics and performance. The first three classes are related to the time period that the active amplifier device is passing current, expressed as a fraction of the period of a signal waveform applied to the input. This metric is known as conduction angle (θ). A class A amplifier is conducting through the entire period of the signal (θ=360°); Class B only for one-half the input period (θ=180°), class C for much less than half the input period (θ<180°). Class D amplifiers operate their output device in a switching manner; the fraction of the time that the device is conducting may be adjusted so a pulse-width modulation output can be obtained from the stage.
Arthur Frank Witulski is an American electrical engineer. He is the Research Associate Professor Electrical Engineering and Computer Science at Vanderbilt University, where his research activities focus on microelectronics and semiconductor devices. He is affiliated with the Radiation Effects and Reliability Group at Vanderbilt University, where he works on the effects of radiation on semiconductor devices and integrated circuits. He also serves as an engineer at the Institute for Space and Defense Electronics at Vanderbilt. He is best known for his work in the field of Power electronics and ionizing radiation response of DC-to-DC converter.
Switching Control Techniques address electromagnetic interference (EMI) mitigation on power electronics (PE). The design of power electronics involves overcoming three key challenges:
- power losses
- EMI
- harmonics
Random pulse-width modulation (RPWM) is a modulation technique introduced for mitigating electromagnetic interference (EMI) of power converters by spreading the energy of the noise signal over a wider bandwidth, so that there are no significant peaks of the noise. This is achieved by randomly varying the main parameters of the pulse-width modulation signal.
