Electricity and Electronics I
For Test #4
a device for repeatedly connecting and interrupting an electric power
contacts are usually provided in addition to the main power
contacts in a circuit used to control the delivery of power to
eutectic alloy solder
a type of alloy that has a very low melting point and
quickly becomes solid when
heat is removed.
frequent starting and stop
ping of a motor for short periods of time.
the lines of force that exist about a magnetic body and collectively
a broad term used to describe any device that controls the
operation of an electr
a type of controller which is designed to start a motor. Motor
starters may include
overload protection devices.
to stop a motor by reconnecting it so that it tries to turn in the oppo
ce that responds to input conditions by making or breaking contacts.
a type of controller used for reversing the rotation of the motor
automatic and orderly control of a series of operations.
oil of wire that, when energized, acts as a magnet and will pull a
moveable iron core or
armature to a new position.
a pit or reservoir for draining or holding liquids.
the transfer of cold or heat through a substance.
an auxiliary device used to switch control circuits and large
the transfer of cold or heat through radiation.
a relay that is designed to maintain contacts by using a
mechanical latch, which can be
either mechanically or electrically.
an opening or hole.
a relay that can be energized and de
energized at variable time
a conductive metal or carbon block that makes contact with a turning
a circular arrangement of bars or segments that are insulated from
each other and the
rotor of a DC motor.
an ac motor where the primary winding on one part (usually
the stator) is connected
to the power source and the secondary
winding on the other
part (usually the rotor) carries an induced
current. These currents produce an
polarity magnetic field in the rotor and the stator. The
the opposite stator and rotor magnetic fields produces torque and caus
es the motor