Page 425 - Understanding Automotive Electronics

2735 | Glossary Page 412 Tuesday, March 10, 1998 1:33 PM

G GLOSSARY

Microcomputer: A small computer which uses an integrated circuit which
contains a central processing unit and other control electronics.
MUX: Multiplexer; a type of electronic switch used to select one of several
input lines.
NO :The various oxides of nitrogen.
x
Op Code: A number which a computer recognizes as an instruction.
Open-Loop Fuel Control: A mode where engine input air/fuel ratio is con-
trolled by measuring the mass of input air and adding the proper mass of fuel to
obtain a 14.7 to 1 ratio.
Operational Amplifier: A standard analog building block with two inputs,
one output, and a very high voltage gain.
Optimal Damping: The damping which produces the very best time
response.
Peripheral: An external input-output device which is connected to a
computer.
Phase Shift: A measure of the delay in degrees between the time a signal
enters a system and the time it shows up at the output as a fraction of a full
cycle of 360˚.
Plant: A system which is to be controlled.
Proportional Amplifier: A control system component which produces a con-
trol output proportional to its input.
Qualitative Analysis: A study which reveals how a system works.
Quantitative Analysis: A study which determines how well a system performs.
RAM: Random access memory; read/write memory.
Random Error: A measurement error which is neither predictable nor correct-
able, but has some statistical nature to it.
ROM: Read only memory; permanent memory used to store permanent pro-
grams.
RPM: Revolutions per minute; the angular speed of rotation of the crankshaft
of an engine or other rotating shaft.
Sample and Hold: The act of measuring a voltage at a particular time and
storing that voltage until a new sample is taken.
Sampling: The act of periodically collecting or providing information about a
particular process.
Semiconductor: A material which is neither a good conductor nor a good
insulator.
Sensor: An energy conversion device which measures some physical quantity
and converts it to an electrical quantity.
Sequential Logic: Logic circuits whose output depends on the particular
sequence of the input logic signals.
SI Engine: Abbreviation for spark-ignited, gasoline-fueled, piston-type,
internal-combustion engine.

412 UNDERSTANDING AUTOMOTIVE ELECTRONICS