Electronic Engineering Dictionary

AGP Bus. The Accelerated Graphics Port bus was widely used as a video expansion bus on personal computers from 1997 to 2006. The AGP electrical standard was derived from the Parallel PCI bus. The fastest speed; AGP 8x used a 533MHz clock with 32 bytes/clock transfers, with a Bandwidth of 2.1GBps. The AGP Bus was rendered obsolete by the introduction of the PCIe interface [PCI Express].

Air-Control Panel. A panel that monitors the dry-air input at each user equipment. [Manufacturers of Environmental Alarms]

Air-Core Inductor. An inductor composed of two or more coils that are wound around a non-metallic core. Normally air-core inductors are found in RF applications. Also see Manufacturers of Inductors.

Air-Core Transformer. A transformer composed of two or more coils that are wound around a non-metallic core. Air-core transformers are lossless and don't suffer from heating due to eddy currents losses. Also refer to Manufacturers of Transformers.

Inductor

Air Dielectric. A component that uses air and not some other material as a separator. Examples include; air used to separate the plates of a capacitor in an Adjustable Capacitor, or air used as a spacer between conductors in a Coax Cable [although a support might be used to keep the cable from being crushed].

Air Gap. The space between two parts or components. The space between two contacts of a switch.

A-Law. A companding algorithm used in digital communications systems. Refer to the telcom section for A-Law IC Functions. A standard compression algorithm, used in digital communications systems of the European digital hierarchy, to optimize, or modify, the dynamic range of an analog signal for digitizing.

Aliasing. An effect that occurs when an analog signal is sampled digitally at a rate that is less than twice the signal frequency. See Nyquist Sampling Rate. In any technology or process involving sampling a signal, e.g., an electrical signal or (a series of images of) a moving subject; processing, storing, or transmitting representations of the samples; and replicating the original signal from the representations: the production of artifacts as a result of sampling at intervals too great to permit faithful replication of the original signal.

Alkaline Battery. A cell that uses zinc as the negative electrode and manganese dioxide as the positive electrode, with an alkaline electrolyte. Related topic; Battery Vendors.

Alligator Clip. A metal clip with jaws. See Types of Alligator Clips

Alloy. A mixture of two or more materials, at least one of which is a metal.

Alloyed Junction. A junction formed by re-crystallization of a molten region of P-type material on an N-type substrate, or vice versa.

All-Pass Filter. An active or passive filter that passes all frequencies applied to it, but normally applies a phase shift between the input and output. Active All-Pass Filter Circuit.

Alpha. The emitter-to-collector current gain in a common-base circuit of a transistor. Also refer to the section covering Transistor Terms. [Transistor Manufacturers].

Altazimuth Mount. A mounting for a directional antenna, in which slewing takes place in the plane tangent to the surface of the Earth or other frame of reference and elevation about, above or below, that plane. Also see Dictionary of Antenna Terms, or Manufacturers of Antenna Pedestals.

Alternate Mark Inversion Signal. [AMI] A pseudoternary signal, representing binary digits, in which (a) successive "marks" are of alternately positive and negative polarity and the absolute values of their amplitudes are normally equal and (b) "spaces" are of zero amplitude.

Alternating Current. [AC] An electrical current that constantly changes amplitude and changes polarity at regular intervals, usually 100 or 120 times per second (50 or 60 cycles per second or 50//60 Hz).

Altitude. The vertical distance of an aircraft or object above a given reference, such as ground or sea level. Additional reference information may be obtained via Airborne Environment Classification per MIL-HDBK-217. Note electrical characteristics of electronic components and heat transfer change with increasing altitude.

Aluminum Creep. The movement of aluminum wire from a point where pressure is applied. The "retreat" of heated aluminum wire as it cools.

Aluminum Electrolytic Capacitor. A capacitor that uses aluminum foil to form the plates of the capacitor, separated by absorbent paper that is saturated with an electrolyte. Read more on Electrolytic Capacitors from the dictionary of capacitor terms.