E

EBCDIC (Extended Binary-Coded Decimal Information Code) - a code for representing keyboard and control characters.

eccentric - two or more objects do not have a common center.

echo - a reflected sound wave.

ECMA (European Computer Manufacturer’s Associated) -

eddy currents - small currents that circulate in metals as currents flow in nearby conductors. Generally unwanted.

EDIF (Electronic Design Interchange Format) - a standard to allow the interchange of graphics and data between computers so that it may be changed, and modifications tracked.

EEPROM (Electrically Erasable Programmable Read Only Memory) -

effective sound pressure - the RMS pressure value gives the effective sound value for fluctuating pressure values. This value is some fraction of the peak pressure value.

EIA (Electronic Industries Association) - A common industry standards group focusing on electrical standards.

electro-optic isolator - uses optical emitter, and photo sensitive switches for electrical isolation.

electromagnetic - a broad range term referring to magnetic waves. This goes from low frequency signals such as AM radio, up to very high frequency waves such as light and X-rays.

electrostatic - devices that used trapped charge to apply forces and caused distribution. An example is droplets of paint that have been electrically charged can be caused to disperse evenly over a surface that is oppositely charged.

electrostatics discharge - a sudden release of static electric charge (in nongrounded systems). This can lead to uncomfortable electrical shocks, or destruction of circuitry.

email (electronic mail) - refers to messages passed between computers on networks, that are sent from one user to another. Almost any modern computer will support some for of email.

EMI (ElectroMagnetic Interference) - transient magnetic fields cause noise in other systems.

emulsify - to mix two materials that would not normally mix. for example an emulsifier can cause oil and water to mix.

enable - a digital signal that allows a device to work.

encoding - a conversion between different data forms.

energize - to apply power to a circuit or component.

energy - the result of work. This concept underlies all of engineering. Energy is shaped, directed and focused to perform tasks.

engineering work stations - are self contained computer graphics systems with a local CPU which can be networked to larger computers if necessary. The engineering work station is capable of performing engineering synthesis, analysis, and optimization operations locally. Work stations typically have more than 1 MByte of RAM, and a high resolution screen greater than 512 by 512 pixels.

EOH (End of Header) - A code in a message header that marks the end of the header block.

EOT (End Of Transmission) - an ASCII code to indicate the end of a communications.

EPROM (Erasable Programmable Read Only Memory) - a memory type that can be programmed with voltages, and erased with ultraviolet light.

EPS (Encapsulated PostScript) - a high quality graphics description language understood by high end printers. Originally developed by Adobe Systems Limited. This standard is becoming very popular.

error signal - a control signal that is the difference between a desired and actual position.

ESD - see electrostatic discharge.

esters - a chemical that was formed by a reaction between alcohol and an acid.

ETX (End Of Text) - a marker to indicate the end of a text block in data transmission.

even parity - a checksum bit used to verify data in other bits of a byte.

execution - when a computer is under the control of a program, the program is said to be executing.

expansion principle - when heat is applied a liquid will expand.

expert systems - is a branch of artificial intelligence designed to emulate human expertise with software. Expert systems are in use in many arenas and are beginning to be seen in CAD systems. These systems use rules derived from human experts.