The Standard Electrical Dictionary / A Popular Dictionary of Words and Terms Used in the Practice of Electrical Engineering

by T. O'Conor Sloane

Fig. 284. MORSE RECORDER OR EMBOSSER.
452 STANDARD ELECTRICAL DICTIONARY.
Recorder, Morse.
A telegraphic receiving apparatus for recording on a strip of paper the
dots and lines forming Morse characters as received over a telegraph
line. Its general features are as follows:
A riband or strip of paper is drawn over a roller which is slightly
indented around its centre. A stylus or blunt point carried by a
vibrating arm nearly touches the paper. The arm normally is motionless
and makes no mark on the paper. An armature is carried by the arm and an
electro-magnet faces the armature. When a current is passed through the
magnet the armature is attracted and the stylus is forced against the
paper, depressing it into the groove, thus producing a mark. When the
current ceases the stylus is drawn back by a spring.

Fig. 285. INKING ROLLER MECHANISM OF MORSE RECORDER.
In some instruments a small inking roller takes the place of the stylus,
and the roller is smooth. The cut, Fig. 285, shows the plan view of the
ink-roller mechanism. J is the roller, L is the ink well, Cl is the arm
by which it is raised or lowered by the electro-magnet, as in the
embosser. S S is the frame of the instrument, and B the arbor to which
the arm carrying the armature is secured, projecting to the right. A
spring is arranged to rub against the edge of the inking roller and
remove the ink from it.
The paper is fed through the apparatus by clockwork. At the present day
sound reading has almost entirely replaced the sight reading of the
recorder.
Recorder, Siphon.
A recording apparatus in which the inked marks are made on a strip of
paper, the ink being supplied by a siphon terminating in a capillary
orifice.
In the cut N S represents the poles of a powerful electro-magnet. A
rectangular coil bb of wire is suspended between the coils. A stationary
iron core a intensifies the field. The suspension wire f f 1 has its
tension adjusted at h. This wire acts as conductor for the current.
453 STANDARD ELECTRICAL DICTIONARY.
The current is sent in one or the other direction or is cut off in
practice to produce the desired oscillations of the coil b b. A glass
siphon n l works upon a vertical axis l. One end l is immersed in an ink
well m. Its longer end n touches a riband of paper o o. The thread k
attached to one side of the coil pulls the siphon back and forth
according to the direction of current going through the electro-magnet
cores. A spiral spring adjusted by a hand-screw controls the siphon. In
operation the siphon is drawn back and forth producing a zigzag line.
The upward marks represent dots, the downward ones dashes. Thus the
Telegraphic Code can be transmitted on it. To cause the ink to issue
properly, electrification by a static machine has been used, when the
stylus does not actually touch the paper, but the ink is ejected in a
series of dots.

Fig. 286. SIPHON RECORDER.
Reducteur for Ammeter.
A resistance arranged as a shunt to diminish the total current passing
through an ammeter. It is analogous to a galvanometer shunt. (See
Multiplying Power of Shunt.)
Reducteur for Voltmeter.
A resistance coil connected in series with a Voltmeter to diminish the
current passing through it. Its resistance being known in terms of the
resistance of the voltmeter it increases the range of the instrument so
that its readings may cover double or more than double their normal
range.
Reduction of Ores, Electric.
Treatment of ores by the electric furnace (see Furnace, Electric.) The
ore mixed with carbon and flux is melted by the combined arc and
incandescent effects of the current and the metal separates. In another
type the metal is brought into a fusible compound which is electrolyzed
while fused in a crucible. Finally processes in which a solution of a
salt of the metal is obtained, from which the metal is obtained by
electrolysis, may be included. Aluminum is the metal to whose extraction
the first described processes are applied.
454 STANDARD ELECTRICAL DICTIONARY.
Refraction, Electric Double.
Double refraction induced in some materials by the action of either an
electrostatic, magnetic or an electro-magnetic field.
The intensity or degree of refracting power is proportional to the
square of the strength of field.
Refreshing Action.
In electro-therapeutics the restoration of strength or of nerve force by
the use of voltaic alternatives, q. v.
Region, Extra-polar.
In electro-therapeutics the area or region of the body remote from the
therapeutic electrode.
Region, Polar.
In electro-therapeutics the area or region of the body near the
therapeutic electrode.
Register, Electric.
There are various kinds of electric registers, for registering the
movements of watchmen and other service. Contact or press buttons may be
distributed through a factory. Each one is connected so that when the
circuit is closed thereby a mark is produced by the depression of a
pencil upon a sheet or disc of paper by electro-magnetic mechanism. The
paper is moved by clockwork, and is graduated into hours. For each
push-button a special mark may be made on the paper. The watchman is
required to press the button at specified times. This indicates his
movements on the paper, and acts as a time detector to show whether he
has been attending to his duty.
Register, Telegraphic.
A term often applied to telegraph recorders, instruments for producing
on paper the characters of the Morse or other alphabet.
Regulation, Constant Current.
The regulation of a dynamo so that it shall give a constant current
against any resistance in the outer circuits, within practical limits.
It is carried out in direct current machines generally by independent
regulators embodying a controlling coil with plunger or some equivalent
electro-magnetic device inserted in the main circuit and necessarily of
low resistance. In some regulators the work of moving the regulator is
executed mechanically, but under electrical control; in others the
entire work is done by the current.
A typical regulator or governor (Golden's) of the first class comprises
two driven friction wheels between which is a driving friction wheel,
which can engage with one driven wheel only at once. It is brought into
engagement with one or the other by a solenoid and plunger.
455 STANDARD ELECTRICAL DICTIONARY.
As it touches one wheel it turns it in one direction. This moves a
sliding contact in one direction so as to increase a resistance. This
corresponds to a motion of the plunger in one direction. As the driving
wheel moves in the opposite direction by a reverse action it diminishes
the resistance. Thus the increase and decrease of resistance correspond
to opposite movements of the solenoid plunger, and consequently to
opposite variations in the current. The whole is so adjusted that the
variations in resistance maintain a constant amperage. The resistance is
in the exciting circuit of the dynamo.
In Brush's regulator, which is purely mechanical, a series dynamo is
made to give a constant current by introducing across the field magnets
a shunt of variable resistance, whose resistance is changed by an
electro-magnet, whose coils are in circuit with the main current. Carbon
resistance discs are used which the electro-magnet by its attraction for
its armature, presses with varying intensity. This alters the
resistance, decreasing it as the current increases and the reverse. As
the connection is in shunt this action goes to maintain a constant
current.
Regulation, Constant Potential.
The regulation of constant potential dynamos is executed on the same
lines as that of constant current dynamos. If done by a controlling
coil, it must for constant potential regulation be wound with fine wire
and connected as a shunt for some part of the machine.
Regulation of Dynamos.
The regulation of dynamos so that they shall maintain a constant
potential difference in the leads of their circuit for multiple arc
systems or shall deliver a constant current in series systems. Hence two
different systems of regulation are required, (a) constant potential
regulation--(b) constant current regulation. The first named is by far
the more important, as it concerns multiple arc lighting, which is the
system universally used for incandescent lighting.
S. P. Thompson thus summarizes the methods of governing or regulating
dynamos. Premising that alteration of the magnetic flux is the almost
universal way of control, it can be done in two ways; first, by varying
the excitation or ampere turns of the field, and second by varying the
reluctance of the magnetic circuit. The excitation or magnetic flux may
be varied
(a) by hand, with the aid of rheostats and commutators in the exciting
circuit;
(b) automatically, by governors, taking the place of the hand;
(c) by compound windings. The magnetic circuit may have its reluctance
caused to vary in several ways;
(d) by moving the pole pieces nearer to or further from the armature;
(e) by opening or closing some gap in the magnetic circuit (field-magnet
core);
(f) by drawing the armature endways from between the pole pieces;
(g) by shunting some of the magnetic lines away from the armature by a
magnetic shunt.
The latter magnetic circuit methods d, e, f, and g, have never met with
much success except on small machines or motors. Method e is adopted in
the Edison motor, the yoke being withdrawn or brought nearer the cores
of the coils. (See Regulation, Constant Current-Regulation, constant
Potential.)
456 STANDARD ELECTRICAL DICTIONARY.
Reguline. adj.
Having the characteristics of a piece of metal, being flexible,
adherent, continuous, and coherent. Applied to electrolytic deposits.
Relative.
Indicating the relation between two or more things without reference to
absolute value of any one of them. Thus one lamp may be of relatively
double resistance compared to another, but this states nothing of the
resistance in ohms of either lamp.
Relay.
A receiving instrument which moves in accordance with impulses of
currents received, and in so moving opens and closes a local circuit,
which circuit may include as powerful a battery as required or
desirable, while the relay may be on the other hand so delicate as to
work with a very weak current.

Fig. 287. RELAY.
The typical relay includes an electro-magnet and armature. To the latter
an arm is attached and the lower end of the arm works in pivots. As the
armature is attracted the arm swings towards the magnet. When the
current is cut off, the armature and arm are drawn back by a spring.
When the arm swings towards the magnet its upper end touching a contact
screw closes the local circuit. When it swings back it comes in contact
with a second screw, with insulated point, and opens the circuit as it
leaves the first named screw.
One terminal connects with the arm through the pivots and frame. The
other connects with the contact screw through the frame carrying it.
Synonym--Relay Magnet.
457 STANDARD ELECTRICAL DICTIONARY.
Relay Bells.
Bells connected by relay connection to a main line for acoustic
telegraphy. A stroke on one bell indicates a dot and on the other a
dash. The system is now nearly extinct.
Relay, Box-sounding.
A relay which is surrounded by or mounted on a resonator or wooden box
of such proportions and size as to reinforce the sound. This enables a
relay to act as a sounder, its weak sounds being virtually magnified so
as to be audible.
Relay Connection.
A connection used in telegraphy, including a local battery, with a short
circuit normally open, but closed by a switch and a sounder or other
appliance. The latter is made very sensitive so as to be worked by a
feeble current, and is connected to the main line. A very slight current
closes the switch and the local battery comes into operation to work a
sounder, etc. When the current ceases on the main line the switch opens
and throws the local battery out of action. The switch is termed a
relay, q. v. A long main line may thus produce strong effects at distant
stations, the intensity of action depending on the local battery.

Fig. 288. RELAY OR LOCAL CIRCUIT.
Relay, Differential.
A relay containing two coils wound differentially, and of the same
number of turns and resistance. If two equal currents pass through the
coils they counteract each other and no action takes place. If there is
a difference in the currents the relay acts as one coil preponderates.
The coils may be wound for uneven currents with different resistance and
number of turns.
Relay, Microphone.
A relay connection applied to a telephone circuit. It consists of a
microphone mounted in front of the diaphragm of a telephone receiver. In
circuit with the microphone is a battery and second telephone receiver.
The microphone is supposed to intensify the sounds of the first
telephone.
458 STANDARD ELECTRICAL DICTIONARY.
Relay, Polarized.
A relay whose armature is of steel, and polarized or permanently
magnetized, or in which a permanent magnet is used as the basis for the
electro-magnets. In the relay shown in the cut the coils shown are
mounted on cores carried on the end of a powerful bent permanent magnet.
Thus when no current passes their upper poles are both of the same sign,
and the horizontally vibrating tongue is held by the magnetic attraction
against one or the other pole piece. If a current is sent through the
electro-magnet it gives opposite polarity to the two polar extensions.
As the end of the vibrating tongue is of polarity determined by the
permanent magnet it is attracted to one pole and repelled from the
other. On cessation of current it remains attached by the permanent
magnetism. If now a current is sent in the opposite direction the two
poles again acquire opposite polarity, the reverse of the former, and
the tongue flies across to the opposite side. On cessation of current it
remains attached as before by the permanent magnetism.
In its movements to and fro the relay tongue opens and closes a contact,
so as to work a sounder or other apparatus. The polarized relay is of
high sensibility, and requires little or no change of adjustment.