Dictionary of Electrical Engineering

Commonly used terms in the Electrical industry.

c
common symbol for speed of light in free space. c = 3 x 1010 cm/s.
C-band
microwave frequency range, 3.95-5.85 Ghz.
C-element
a circuit used in an asynchronous as an interconnect circuit. The function of this circuit is to facilitate the handshaking communication protocol between two functional blocks.
cable
an assembly of insulated conductors, either buried or carried on poles (aerial cable).
cable limiter
a cable connector that contains a fuse. Cable limiters are used to protect individual conductors that are connected in parallel on one phase of a circuit.
cable tray
a specialized form of raceway used to hold insulated electric power cables in a building.

See computer-aided design
cage-rotor induction motor
an induction motor whose rotor is occupied by copper or aluminum bars, known as rotor bars, instead of windings. Also commonly referred to as a squirrel-cage induction motor.
candela (cd)
unit of measurement for luminous intensity (illuminating power in lumens/sr). The luminous intensity of 1/60 of 1cm2 of projected area of a blackbody radiator operating at the temperature of solidification of platinum (2046K). Historically, the unit of measurement for the light emitted by one flame of a specified make of candle.
candle power

See candela
candlepower distribution
a curve, generally polar, representing the variation of luminous intensity of a lamp or luminaire in a plane through the light center.
capacitance
the measure of the electrical size of a capacitor, in units of farads. Thus a capacitor with a large capacitance stores more electrons (coulombs of charge) at a given voltage than one with a smaller capacitance.
In a multiconductor system separated by nonconductive mediums, capacitance (C) is the proportionality constant between the charge (q) on each conductor and the voltage (V ) between each conductor. The total equilibrium system charge is zero. Capacitance is dependent on conductor geometry, conductor spatial relationships, and the material properties surrounding the conductors.
Capacitors are constructed as two metal surfaces separated by a nonconducting electrolytic material. When a voltage is applied to the capacitor the electrical charge accumulates in the metals on either side of the nonconducting material, negative charge on one side and positive on the other. If this material is a fluid then the capacitor is electrolytic; otherwise, it is nonelectrolytic.
capacitive reactance
the opposition offered to the flow of an alternating or pulsating current by capacitance measured in ohms.
capacitor bank
(1) an assembly at one location of capacitors and all necessary accessories, such as switching equipment, protective equipment, and controls, required for a complete operating installation.
(2) a group of (typically 3) capacitors mounted on an electric power line for voltage boosting or power factor correction.
capacitor-start induction motor (CSIM)
a single-phase induction motor with a capacitor in series with its auxiliary winding, producing nearly a 90. phase difference between the main winding and the auxiliary winding currents at starting. This results in a high starting torque, so this motor is used for hard-to-start loads. The auxiliary winding and capacitor are removed from the circuit by a centrifugal switch as the machine approaches operating speed.
carbon brush
a block of carbon used to make an electrical contact to a rotating coil via the commutator of a DC machine or the slip rings of a synchronous machine.
carbon dioxide (CO2)
linear gas molecule consisting of one carbon and two oxygen atoms, medium for an important class
of lasers.
carbon dioxide laser
laser in which the amplifiying medium is carbon dioxide gas; efficient, powerful, and commercially important laser that is pumped and configured in many ways and has its principal output lines in the mid-infrared.
carbon resistor thermometer
a carbon resistor whose temperature sensitivity provides good temperature resolution.
ceramic ferrite
a relatively inexpensive permanent magnet material with decent coercivity and low energy product that is composed of strontium or barium oxide and iron oxide. Also called hard ferrite.