alternating current

(redirected from Alternating-current)
Also found in: Dictionary, Thesaurus, Encyclopedia.

current

 [kur´ent]
1. something that flows.
2. specifically, electricity transmitted through a circuit.
alternating current a current that periodically flows in opposite directions; its amplitude fluctuates as a sine wave.
convection current a current caused by movement by convection of warmer fluid into an area of cooler fluid.
direct current a current that flows in one direction only; when modeled as a wave, its amplitude is constant. When used medically it is called galvanic current. This current has distinct and important polarity and marked secondary chemical effects.
galvanic current a steady direct current.
current of injury an electric current that flows between injured myocardium and normal myocardium, because such cells have a reduced membrane potential; it may be either diastolic or systolic.
current of injury, diastolic the current that flows from injured to noninjured tissue during electrical diastole.
current of injury, systolic the current that flows from healthy tissue to injured tissue during electrical systole.
inwardly rectifying current current that rectifies so that it passes more easily towards the interior of a cell.
leakage current the electrical current that exists in the parts or metal case of electrical equipment.
outwardly rectifying current current that rectifies so that it passes more easily towards the exterior of a cell.
potassium rectifying c's transmembrane currents that rectify inwardly or outwardly to make adjustments in cellular functions; they are mainly responsible for the repolarization phase of the action potential. There are at least six mechanisms by which potassium ions move across cardiac cell membranes in the role of rectifier.

al·ter·nat·ing cur·rent (AC),

a current that flows first in one direction then in the other, for example, 60-cycle current.

alternating current

An MRI term for a continuously changing flow of electrons that alternates its polarity at a periodic rate. In the US, the current changes at a frequency of 60 Hz.

al·ter·nat·ing cur·rent

(AC, ac, a.c.) (awl'tĕr-nāt-ing kŭr'rĕnt)
Electric current that reverses direction (positive-negative polarity) many times each second (with each rotation of the armature of the dynamo generating the current).

al·ter·nat·ing cur·rent

(AC, a.c.) (awl'tĕr-nāt-ing kŭr'rĕnt)
Electric current that reverses direction (positive-negative polarity) many times each second (with each rotation of the armature of the dynamo generating the current).
References in periodicals archive ?
Therefore, the induction relays are more sensitive to outer magnetic field than direct- or alternating-current relays.
Alternating-current motors dominate the market for fractional-horsepower motors used extensively in industrial manufacturing.
Until such preventive measures are taken to protect the public, and until physicians and public-health officials begin acknowledging the power-line hazard and seriously investigate the cancer clusters associated with it, alternating-current magnetic fields given off by substations and high current lines ...
Alternating-current motors that have been used for more than 10 years in Europe to power high-speed passenger trains are being readied to debut on freight trains in the United States.
Their topics include semiconductor power switches and passive components, the control of power electronic devices, line-commutated converters, conversion from direct current to direct current, inverters and alternating-current converters based on completely controllable switches, pulse-width modulation and power quality control, resonant converters, and applications of power electronics.
His topics are the basic structure and modeling of electric machines and power converters, reference frame transformation and transient state analysis of three-phase alternating-current machines, the design of regulators for electric machines and power converters, vector control, position/speed sensorless control of alternating-current machines, and practical issues.

Full browser ?