18WuD2x

354 IEE • illuminated pushbutton
IEE Abbreviation of Institution of Electrical Engineers
(British).
IEEE Abbreviation of Institute of Electrical and Electronics
Engineers.
IES Abbreviation of Illuminating Engineering Society.
IF Abbreviation of INTERMEDIATE FREQUENCY.
IF amplifier See INTERMEDIATE-FREQUENCY
AMPLIFIER.
I FB In an integrated circuit, current limit feedback
or feedback current.
IF channel See INTERMEDIATE-FREQUENCY
CHANNEL.
IF converter The converter (first detector-oscillator)
section of a superheterodyne radio receiver.
IFF Abbreviation of IDENTIFICATION, FRIEND OR
FOE.
IF gain 1. The amplification provided by the intermediate-frequency
(IF) channel of a superheterodyne
receiver, usually specified in decibels. 2. A
control that allows adjustment of the amplification
in the IF channel of a superheterodyne radio
receiver.
IF interference See INTERMEDIATE-FREQUEN-
CY INTERFERENCE.
IFIPS Abbreviation of International Federation of
Information Processing Societies.
IF selectivity See INTERMEDIATE-FREQUENCY
SELECTIVITY.
IF strip A (sometimes removable) circuit section
containing a complete intermediate-frequency
channel.
IF/THEN/ELSE In computer systems and artificial
intelligence, a two-way choice that is made during
the execution of a program. For example, in
finding the absolute value of a number, the logic
proceeds as follows: “IF x < 0, THEN multiply x by
-1; otherwise (ELSE) leave it alone.”
IF transformer See INTERMEDIATE-FREQUEN-
CY TRANSFORMER.
I G Symbol for GATE CURRENT.
I G Symbol for GRID CURRENT.
IGFET Abbreviation of INSULATED-GATE FIELD-
EFFECT TRANSISTOR.
ignition coil A small open-core transformer having
a high step-up turns ratio for converting
6- or 12-volt battery potential to the high voltage
needed in an automotive ignition system.
ignition interference Electrical noise generated
by the ignition system of an internal combustion
engine.
ignition potential 1. The minimum voltage
needed to cause electrical discharge in an internal
combustion engine. 2. See BREAKDOWN
VOLTAGE, 1, 2.
ignition reserve The extra voltage provided by the
starter, as compared with the voltage actually
needed for ignition of an internal-combustion engine.
ignition system An electrical or electronic system
that supplies the high voltage in an automotive
engine. See, for example, CAPACITOR-
DISCHARGE IGNITION SYSTEM.
ignition voltage See IGNITION POTENTIAL.
ignitron A form of rectifier tube that contains ionized
mercury. It is used with some extremely
high-voltage power supplies.
Iron anodes
Shields
Steel tank
Water jacket
Mercury cathode
−
ac supply
+
ignitron
dc load
ignore character 1. A character used as a signal to
inhibit an action. 2. A digital character that is ignored
by the system.
I GSS Symbol for GATE REVERSE CURRENT in a
field-effect transistor.
IGY Abbreviation for INTERNATIONAL GEOPHYSI-
CAL YEAR.
I H 1. Symbol for HOLD CURRENT. 2. Symbol for
HOLDING CURRENT.
IHF Abbreviation of INHIBIT FLIP-FLOP.
IHFM Abbreviation for Institute of High Fidelity
Manufacturers.
ihp Abbreviation of INDICATED HORSEPOWER.
ihp-hr Abbreviation of INDICATED HORSE-
POWER-HOURS.
I i 1. Symbol for INPUT CURRENT. 2. Symbol for IN-
STANTANEOUS CURRENT (also, i).
I K Symbol for CATHODE CURRENT.
I L Symbol for current in an inductor.
I 2 L Abbreviation of INTEGRATED INJECTION
LOGIC. (Also IIL.)
illegal character 1. A character or bit group that is,
according to some standard, invalid. 2. A bit group
that represents a symbol in a character set.
illuminance The amount of luminous flux received
per unit surface area, measured in lux (lumens
per square meter).
illuminant-C In color television, the reference
white that closely resembles average daylight.
illuminated pushbutton See LIGHTED PUSH-
BUTTON.