18WuD2x

458 motorboating filter • M scan
MOTORBOATING caused by unwanted positive
feedback. Also see DECOUPLING FILTER.
motor capacitor See MOTOR-RUN CAPACITOR
and MOTOR-START CAPACITOR.
motor constant The ability, expressed numerically,
of a torque motor to convert electric input
power into torque.
motor converter An electromechanical device for
converting alternating current to direct current.
motor-driven relay An electromechanical relay
whose contacts are opened and closed by a rotating
motor.
motor effect Magnetic force between adjacent current-carrying
conductors.
motor-generator A combination of motor and generator
in a single machine assembly. A common
arrangement is a low-voltage motor turning a
high-voltage generator. The machine shafts can
be coupled, or the motor can turn the generator
through a belt, chain, or gear train.
motor meter A meter in which the movable element
is essentially a continuously rotating motor.
See, for example, KILOWATT-HOUR METER.
motor-run capacitor A power-factor-boosting capacitor
connected (together with its auxiliary
winding) in parallel with the main winding in an
induction motor. Also see CAPACITOR MOTOR.
motor-speed control A method of controlling the
speed of a motor by varying the magnitude
and/or phase of its current. Electronic devices
usually use diode, diac, or triac circuits.
motor-start capacitor A capacitor that, with an
auxiliary winding, is switched into a motor circuit
during the starting period, and is automatically
disconnected (with the winding) after the motor
reaches normal running speed. Also see CAPACI-
TOR MOTOR.
motor starter See STARTING BOX.
mould See MOLD.
mount 1. A mechanical device with which a component
is attached to a circuit board or chassis.
2. The attachment of a circuit board to a
chassis. 3. The hardware with which an antenna
is attached to a mast. 4. The hardware
with which a microphone is attached to a boom
or other support. 5. In general, any attaching
hardware.
Mountain standard time Abbreviation, MST. Local
mean time at the 105th meridian west of
Greenwich. Also see GREENWICH MEAN TIME,
STANDARD TIME, TIME ZONE, and COORDI-
NATED UNIVERSAL TIME.
mounting flange The portion of a speaker frame,
usually made of metal, that is equipped with
holes for attachment to a cabinet or panel.
mouse A pointing device commonly used with personal
computers. It is about the size of a candy
bar. The computer operator moves the display
pointer or cursor by sliding the mouse on a flat
surface. Functions and commands are executed
by pressing a button (clicking) on the device.
mouth The radiating end of a horn (antenna, loudspeaker,
etc.).
MOV Abbreviation of METAL-OXIDE VARISTOR.
movable-coil meter See D’ARSONVAL METER.
movable-coil modulator See ELECTROMECHANI-
CAL MODULATOR.
movable contact The traveling contact in a relay
or switch. Compare FIXED CONTACT.
movable-iron meter See IRON-VANE METER.
movies on demand In television, a system that
makes it possible for subscribers to choose the
programs they want to see, and also to choose the
viewing times for the programs.
moving-coil galvanometer A galvanometer whose
movable element is a coil of fine wire suspended
or pivoted between the poles of a magnet.
moving-coil microphone See DYNAMIC MICRO-
PHONE.
moving-coil motor The driving mechanism of a
moving-coil DYNAMIC SPEAKER.
moving-coil pickup See DYNAMIC PICKUP.
moving-coil speaker See DYNAMIC SPEAKER.
moving-conductor microphone See VELOCITY
MICROPHONE.
moving-diaphragm meter A headphone used as a
sensitive indicator in alternating-current bridge
measurements.
moving element In an electromechanical device,
the portion that moves physically under variable
operating conditions.
moving-film camera An oscilloscope camera in
which the film is drawn past the lens continuously
at a constant speed, rather than being advanced
frame by frame, as in a motion-picture
camera.
moving-iron meter See IRON-VANE METER.
moving-vane meter See IRON-VANE METER.
mp Abbreviation of MELTING POINT.
m p Symbol for MASS OF PROTON AT REST.
MPEG Abbreviation for MOTION PICTURE EX-
PERTS GROUP.
MPG Abbreviation of microwave pulse generator.
mph Abbreviation of miles per hour. Also, mi/h.
MPO Abbreviation of maximum power output.
mps 1. Abbreviation of meters per second. Also,
m/s. 2. Abbreviation of miles per second. Also,
mi/s.
MPT Abbreviation of MAXIMUM POWER TRANS-
FER.
MPX Abbreviation of MULTIPLEX.
MR Abbreviation of MEMORY REGISTER.
mrad Abbreviation of MILLIRADIAN.
MRIA Abbreviation of Magnetic Recording Industry
Association.
mrm Abbreviation of milliroentgens per minute.
MS Abbreviation of MASS SPECTROMETER.
m 2 /s Abbreviation of meters squared per second.
The unit of kinematic viscosity.
M scan In radar operations, a modified A-scan display
in which a pedestal signal is moved along the
base line to a point where it coincides with the