A

Abnormal Failure     An artificially induced failure of a component, usually as a result of "abnormal" testing for regulatory agency safety compliance.

AC - Alternating Current     Used to indicate that voltage or current in a circuit that is alternating in polarity at a set frequency, most often 50 or 60 Hz.

AC Input Current     The current drawn under the maximum DC load. Safety agencies require this be marked on the label.

AC Input Frequency     The nominal range of 47 to 63 Hz is important in linear power supplies, but most switchers are insensitive to input frequency and can operate from DC to 400Hz. This is especially important in countries where the power may be of poor quality.

AC Input Voltage     The nominal range on the power supply label as approved by the safety agency is always 10% less than the usable input voltage range. For example, a switching power supply with a nominal 100 to 240VAC has an actual range of 90 to 264VAC. Our data sheet shows the usable voltage range; the label will show the safety agency rating.

AC Inrush Current     The instantaneous current drawn when the power supply is turned on cold. Larger power supplies generally incorporate a thermistor to limit this amount. It is most important in considering an AC switch rating.

Agency Approval     UL, CSA, and TUV are safety agencies that test specifications such as component spacing, HI-pot insulation, leakage currents, circuit board flammability, and temperature rating.

Ambient Temperature     The still air temperature in the immediate vicinity of a power supply, measured a minimum of 4 inches from the supply.

AMP - Ampere     An AMPERE or an AMP is a unit of measurement for electrical current or rate of flow of electrons (coulombs per second) through a wire. If a group of electrons whose total charge is 1 coulomb passes a point in a conductor in 1 second, the electric current is 1 ampere. Its mathematical symbol is "I". In an AC power system, current (AMPS) is delivered to a load through a wire called the "hot" wire and returns through a wire called the "neutral" wire.

ANSI - American National Standards Institute     An industry body that publishes standards, such as standards developed by the IEEE. http://www.ansi.org

Applied Patient Current     Any diagnostic or therapeutic current intended to be administered to a patient. This includes currents applied for measurement purposes.