Fig. 350. CHARACTERISTIC CURVES OF SHUNT AND SERIES WINDING.
The object of compound winding is to make a self-regulating dynamo and
this object is partly attained for a constant speed.
The characteristic curves of shunt and series winding are of opposite
natures. The first increases in electro-motive force for resistance in
the outer circuit, the latter decreases under the same conditions. If
the windings are so proportioned that these conditions for each one of
the two windings are equal and opposite, it is evident that the
characteristic may be a straight line. This, however, it will only be at
a single speed of rotation.
579 STANDARD ELECTRICAL DICTIONARY.
Winding, Disc.
A winding which (S. P. Thompson) may be treated as a drum winding
extended radially, the periphery corresponding to the back end of the
drum. The magnet poles are generally placed so as to face the side or
sides of the disc.
Winding, Lap.
A method of winding disc and drum armatures. It consists in lapping back
each lead of wire towards the preceding lead upon the commutator end of
the armature. Thus taking the letter U as the diagrammatical
representation of a turn of wire in connecting its ends to the
commutator bars they are brought towards each other so as to connect
with contiguous commutator bars. This carries out the principle of
keeping the two members of the U moving in regions of opposite polarity
of field, so that the currents induced in them shall have opposite
directions, thus producing a total current in one sense through the bent
wire.
Winding, Long Shunt.
A system of compound winding for dynamos and motors. The field is wound
in series and, in addition thereto, there is a shunt winding connected
across from terminal to terminal of the machine, and which may be
regarded either as a shunt to the outer circuit, or as a shunt to the
series-field and armature winding. (See Winding, Short Shunt.)
Synonyms--Series and Long Shunt Winding.
Winding, Multiple.
A winding of an electro-magnet, in which separate coils are wound on the
core, so that one or any number may be used as desired in parallel or in
series. For each coil a separate binding post should be provided.
Winding, Multipolar.
Winding adapted for armatures of multi-polar dynamos or motors.
Winding, Series.
A method of winding a generator or motor, in which one of the
commutator-brush connections is connected to the field-magnet winding;
the other end of the magnet winding connects with the outer circuit. The
other armature-brush connects with the other terminal of the outer
circuit.
Winding, Series and Separate Coil.
A method of automatic regulation applied to alternating current dynamos.
Winding, Short Shunt.
A method of compound winding for dynamos and motors. The field is wound
in series, and in addition thereto there is a shunt winding connected
from brush to brush only, thus paralleling the armature. (See Winding,
Long Shunt.)
Synonyms--Series and Short Shunt Winding.
580 STANDARD ELECTRICAL DICTIONARY.
Winding, Shunt.
A method of winding a generator or motor. Each commutator-brush has two
connections. One set are the terminals of the outer circuit, the other
set are the terminals of the field-magnet windings. In other words, the
field-magnet windings are in shunt or in parallel with the outer
circuit.
Winding, Shuttle.
A method of dynamo or motor-armature winding. A single groove passes
longitudinally around the core and in this the wire is continuously
wound. The system is not now used. The old Siemens' H armature
illustrates the principle.
Winding, Wave.
A method of winding disc and drum armatures. It consists in advancing
the commutator ends of the U shaped turns progressively, so that as many
commutator bars intervene between any two consecutive commutator
connections of the wire as there are leads of wire on the drum between
consecutive leads of the wire. This is carried out with due regard to
the principle that taking the letter U as the diagrammatical
representation of a turn of wire, its two members must move through
regions of the field of opposite polarity.
Wire Finder.
A galvanometer or other instrument used for identifying the ends of a
given wire in a cable containing several.
Work.
When a force acts upon a body and the body moves in the direction of the
force, the force does work. Hence, work is the action of a force through
space against resistance.
It is generally expressed in compound units of length and weight, as
foot-pounds, meaning a pound raised one foot.
Work, Electric, Unit of.
The volt-coulomb, q. v., or watt-second, as it is often termed.
Working, Diode.
In multiplex telegraphy the transmission of two messages,
simultaneously, over one wire. (See Telegraphy, Multiple.)
Working, Contraplex.
A variety of duplex telegraphy in which the messages are sent from
opposite ends of the line, simultaneously, so as to be transmitted in
opposite directions. (See Working, Diplex.)
Working, Diplex.
In duplex telegraphy the sending of two independent messages from the
same end of the line in the same direction.
581 STANDARD ELECTRICAL DICTIONARY.
Working, Double Curb.
A method of working telegraph lines. When a signal is sent the line is
charged. This has to be got rid of, and is an element of retardation. In
double curb working it is disposed of by sending a momentary current
first in the reverse, and then in the same, and finally in the reverse
direction. This is found to reduce the charge to a very low point.
Working, Hexode.
In multiplex telegraphy the transmission of six messages simultaneously
over one wire. (See Telegraphy, Multiplex.)
Working, Pentode.
In multiplex telegraphy the transmission of five messages simultaneously
over one wire. (See Telegraphy, Multiplex.)
Working, Reverse Current.
A method of telegraphy, in which the currents are reversed or alternated
in direction.
Working, Single Curb.
A simpler form of telegraph signaling than double curb working. It
consists in sending a reverse current through the line for each signal
by reversing the battery connection.
Working, Tetrode.
In multiplex telegraphy the transmission of four messages simultaneously
over the same line. (See Telegraphy, Multiplex.)
Working, Triode.
In multiplex telegraphy the transmission of three messages
simultaneously over the same wire. (See Telegraphy, Multiplex.)
Work, Unit of.
The erg, q. v. It is the same as the unit of energy, of which work is
the corelative, being equal and opposite to the energy expended in doing
it. There are many other engineering units of work, as the foot-pound
and foot-ton.
Yoke.
In an electro-magnet, the piece of iron which connects the ends furthest
from the poles of the two portions of the core on which the wire is
wound.
Zamboni's Dry Pile.
A voltaic pile or battery. It is made of discs of paper, silvered or
tinned on one side and sprinkled on the other with binoxide of
manganese. Sometimes as many as 2,000 of such couples are piled up in a
glass tube and pressed together with two rods which form the terminals.
They maintain a high potential difference, but having very high
resistance and slight polarization capacity, give exceedingly small
quantities.
Zero.
(a) The origin of any scale of measurement.
(b) An infinitely small quantity or measurement.
582 STANDARD ELECTRICAL DICTIONARY.
Zero, Absolute.
From several considerations it is believed that at a certain temperature
the molecules of all bodies would touch each other, their kinetic motion
would cease, and there would be no heat. This temperature is the
absolute zero. It is put at -273° C. (-459° F.)
[Transcriber's note; The modern value is 0
°
Kelvin, -273.15
°
C, or
-459.67
°
F. The lowest reported temperature observed is 1E-10
°
K.]
Zero, Potential.
Conventionally, the potential of the earth. True zero potential could
only exist in the surface of a body infinitely distant from other
electrified bodies.
Zero, Thermometric.
There are three thermometric zeros. In the Réaumur and centigrade
scales, it is at the temperature of melting ice; in the Fahrenheit
scale, it is 32° F. below that temperature, or corresponds to -17.78° C.
The third is the absolute zero. (See Zero, Absolute.)
Zinc.
A metal; one of the elements; atomic weight, 65.1;
specific gravity, 6.8 to 7.2.
microhms.
Resistance at 0° C. (32° F.), per centimeter cube, 5.626
Resistance at 0° C. (32° F.), per inch cube, 2.215
Relative resistance (silver = 1), 3.741
ohms.
Resistance of a wire, 1 foot long, weighing 1 grain, .5766
(a) 1 foot long, 1 millimeter diameter, 33.85
(b) 1 meter long, weighing 1 gram, .4023
(c) 1 meter long, 1 millimeter diameter, .07163
Zinc is principally used in electrical work as the positive plate in
voltaic batteries.
Zincode.
The terminal connecting with the zinc plate, or its equivalent in an
electric circuit; the negative electrode; the kathode. A term now little
used.
Zinc Sender.
An apparatus used in telegraphy for sending a momentary reverse current
into the line after each signal, thus counteracting retardation.
Zone, Peripolar.
In medical electricity, the region surrounding the polar zone, q. v.
Zone, Polar.
In medical electricity, the region surrounding the electrode applied to
the human body.