Dictionary of Electrical Engineering

Commonly used terms in the Electrical industry.

electronic overload device
an overload device that employs an electronic circuit to sense motor voltage and current for the purpose of providing precise motor overload protection. See also overload heater, overload relay.
electronic switch
an electronic circuit that controls analog signals with digitary (binary) signals.
electronic transition
alteration in the electronic structure of a material such that one electron temporarily changes its energy level through the absorption or emission of energy.
electronic warfare
contention for the control of the electromagnetic (EM) spectrum, to allow active and passive EM sensing and communications while denying the same ability to adversaries. Includes deceptive EM techniques.
electronically commutated machine
a DC machine with rotor-mounted permanent magnets, and concentrated (square) stator windings. The machine fundamentally behaves like a DC machine with linear speed and torque characteristics, and hence is also called a brushless DC machine. The machine is distinguished from conventional DC machines in its substitution of a six-switch inverter for brushes and copper commutator bars and in its need for the rotor position information in real time.
electroplastic effect
plastic deformation of metals with the application of high-density electric current.
electroplastic smart material
material with smart properties of elastic deformation changes proportional to a controlled electric current applied in proportion to the sensed deformation.
electroslag welding
a welding process that produces coalescence of metals with molten slag that melts the filler metal and the surfaces of the parts to be joined.
electrostatic discharge (ESD)
the discharge of a body through a conducting path between two pins of an IC. Circuits located at the inputs and outputs of ICs protect the internal devices from ESD events.
electrostatic precipitator
a method of extracting dust from stack gases or ventilating systems in which ions are laid on the dust particles by high-voltage electrodes and then attracted electrostatically into a trap.
electrostatic voltmeter
a voltmeter, typically used for voltages in the kilovolt range, in which the pointer is moved by the electrostatic attraction of a pair of metal plates across which the voltage to be measured is applied.
elliptical polarization
the polarization state of a radiated electromagnetic field in which the tip of the electric field vector traces an ellipse as a function of time for a fixed position. The sense of rotation of the electric field vector is either right-hand or left-hand (clockwise or counter-clockwise). Circular polarization and linear polarization are special cases of elliptical polarization.

See electromagnetic compatibility

See electromagnetic interference
EMI filter

See electromagnetic interference filter
the fraction of the power incident on a material that is reradiated after being absorbed by the material. For a material in thermal equilibrium, the emissivity is equal to the absorptivity.

See electromagnetic pulse
the Electro-Magnetic Transient Program, a computer program which simulates an electric power system such that its response to disturbances may be accurately predicted.
a box, cabinet, wall, fence, barrier, or other means designed to protect personnel from accidentally contacting energized electrical parts and to protect the electrical parts from physical damage.
bell the cap that forms the end of the stator housing for an electric machine with a cylindrical frame.