Glossary of Power Terms
Alternating Current (AC): The current that is commonly flowing through
the electrical outlets in your home. It is an electrical current in the form of
a sine wave that oscillates up and down continuously.
Amp: An abbreviation for Ampere. This is a unit of electrical current.
Direct Current (DC): An electrical current flowing in one direction only.
DC current does not have a wave form.
Electromagnetic Interference (EMI): Electrical interference generated by
appliances and many other electrical components that cause degradation
of sound and picture quality in audio and video equipment.
Ground: A conducting object, such as a wire, that is connected to a
position of zero-voltage potential. Common connecting points are ground
rods or cold-water pipes that are connected to the Earth.
Joule Rating: A measure of electrical energy. The higher the joule rating,
the more electrical surges a device can absorb before failing.
Maximum Spike Current: The maximum current (in Amps) that can be
absorbed before failing. The higher the maximum spike current, the more
current a device can absorb without failing.
Radio Frequency Interference (RFI): Electromagnetic radiation, which
is emitted by electrical circuits carrying rapidly changing signals as a by-
product of their normal operation, and which causes interference or noise
to be induced in other circuits.
Spike: A very fast transient variation in voltage or current. Many small
transients, over time, cause components to wear and fail.
Surge: An increase in voltage or current significantly above the designated
level in a flow of electricity.
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