- Bias (electrical engineering)
electrical engineering, the term bias has the following meanings:
# A systematic deviation of a value from a reference value.
# The amount by which the average of a
setof values departs from a reference value.
# Electrical, mechanical, magnetic, or other force (field) applied to a device to establish a reference level to operate the device.
telegraphsignaling systems, the development of a positive or negative DC voltageat a point on a line that should remain at a specified reference level, such as zero.
:"Note:" A bias may be applied or produced by (i) the electrical characteristics of the line, (ii) the
terminal equipment, and (iii) the signaling scheme.
Federal Standard 1037Cand from MIL-STD-188)
Most often, bias simply refers to a fixed DC voltage applied to the same point in a circuit as an AC signal, frequently to select the desired operating response of a semiconductor or other electronic component (forward or reverse bias). For example, a bias
voltageis applied to a transistorin an electronic amplifierto allow the transistor to operate in a particular region of its transconductancecurve; a (much higher) bias voltageis also often applied to the grid electrodes in a vacuum tubefor precisely the same reason.
A hot bias can lower the tube life span, but a "cool" biased can induce
Bias is also the term used for a high-frequency signal added to the audio signal recorded on
magnetic tape. See tape bias.
Bias is used in
direct broadcast satellites such as DirecTVand Dish Network, the IRDbox actually powers the feedhornor LNB receiver mounted on the dish arm. This bias is changed from a lower voltage to a higher voltage to select the polarizationof the LNB, so that it receives signals that are polarized either clockwiseor counterclockwise, thereby allowing it to receive twice as many channels.
Wikimedia Foundation. 2010.
Look at other dictionaries:
Bias (disambiguation) — Bias is an inclination towards something, or a predisposition, partiality, prejudice, preference, or predilection. Bias may also refer to:In science and statistics: * Bias (statistics), the systematic distortion of a statistic ** A biased sample… … Wikipedia
Bias — This article is about different ways the term bias is used . For other uses, see Bias (disambiguation). Bias is an inclination to present or hold a partial perspective at the expense of (possibly equally valid) alternatives. Bias can come in many … Wikipedia
Tape bias — is the term for two phenomena, DC bias and AC bias, that improve the fidelity of analogue magnetic tape sound recordings. DC bias is the addition of a direct current to the audio signal that is being recorded. AC bias is the addition of an… … Wikipedia
Electronic engineering — is a discipline dealing with the behavior and effects of electrons (as in electron tubes and transistors) and with electronic devices, systems, or equipment.The term now also covers a large part of electrical engineering degree courses as studied … Wikipedia
Education and training of electrical and electronics engineers — Both electrical and electronics engineers typically possess an academic degree with a major in electrical/ electronics engineering. The length of study for such a degree is usually three or four years and the completed degree may be designated as … Wikipedia
Network analysis (electrical circuits) — Linear Network Analysis Elements … Wikipedia
Mechanical engineering technology — is the application of physical principles and current technological developments to the creation of useful machinery and operation design. Technologies such as solid models may be used as the basis for finite element analysis (FEA) and / or… … Wikipedia
George Washington University School of Engineering and Applied Science — The School of Engineering and Applied Science (SEAS) is a college within The George Washington University in Washington, D.C. which specializes in engineering, technology and communications, and transportation. The school has both undergraduate… … Wikipedia
Insulator (electrical) — Ceramic insulator at railways Conducting copper wire insulate … Wikipedia
electronics — /i lek tron iks, ee lek /, n. (used with a sing. v.) the science dealing with the development and application of devices and systems involving the flow of electrons in a vacuum, in gaseous media, and in semiconductors. [1905 10; see ELECTRONIC,… … Universalium