Improvements in Means for Indicating Variations in Electric › Currents or Regulating Electrical Apparatus.
Year: 1884

page_text: Improvements in Means for Indicating Variations in Electric ›
Currents or Regulating Electrical Apparatus..
: 0
[Communicated to him from abroad by Thomas Alva Edison, of Menlo Park,
in the County of Middlesex and State of New Jersey, United States of
America.]
I THOMAS JOHN HANDFORD of 42 Southampton Buildings in the County of
Middlesex Patent Agent do hereby declare the nature of the said Invention for
IMPROVEMENTS IN MEANS FOR INDICATING VARIATIONS IN ELECTRIC CURRENTS
OR REGULATING ELECTRICAL APPARATUS to be as follows:-
<<
The object of this Invention is to produce an efficient apparatus for indicating
variations of electro motive force in an electric circuit, preferably for use in
connection with systems of electrical distribution to show the changes in pressure
in the various parts of the district. The apparatus is also capable of use in
automatically regulating the electro-motive force to correspond with such
variations.
The communicator of this Invention has discovered that if a conducting
substance is interposed any where in the vacuous space within the globe of an
incandescing electric lamp and the said conducting substance is connected outside
of the lamp with one terminal, preferably the positive one of the incandescing
conductor, a portion of the current will when the lamp is in operation pass through
the shunt circuit thus formed, which shunt includes a portion of the vacuous space
within the lamp. This current he has found to be proportional to the degree of
incandescence of the conductor or candle power of the lamp.
Now this Invention consists in the utilization of this discovery for indicating
or regulating variations in electro-motive force or for affecting electrical apparatus
in any desired manner.
By connecting a device for indicating current changes. in the shunt circuit
changes in the candle power of the lamp and consequently in the electro-motive
force of the source of supply are made apparent, or if instead of an indicating
device the variations in electro-motive force are made to affect circuit controlling
apparatus, automatic regulators or other electrical apparatus may be controlled
thereby.

page_text: .
In applying this Invention to a system of incandescing electric lighting I place
a standard lamp having within its globe a piece of platinum, by preference a thin
plate though platinum wire may be used placed preferably between the limbs of
its carbon conductor such platinum. piece being in connection with the circuit
whose electrical condition is to be observed, connecting said terminals similarly to
those of the other lamps of the system and making an additional connection
from the positive terminal preferably of the lamp circuit to one terminal of
a galvanometer or other indicator and from the platinum piece through a wire
sealed in the glass to the other terminal of the galvanometer or indicator.
The galvanometer if one is used is provided with a torsional device for holding
its needle at zero under a normal current so that variations above or below the
normal deflect the needle in one direction or the other.
If the electro-motive force in the system and consequently the candle power
of the lamps increases the indicating lamp varies with the rest and the current
from it to the galvanometer is increased causing the deflection of the galvanometer
needle and conversely a decrease in electro-motive force in the system produces an
opposite deflection.
The galvanometer needle may be made to close circuit to electrically operated
devices for accomplishing the automatic regulation of the generator supplying
current to the system or for any other purpose.
An adjustable resistance may be placed in circuit with the indicating lamp to
maintain the circuit at the standard lamp resistance.
A second indicating lamp may be placed in a shunt around the one constantly
in use and may be thrown into circuit occasionally so that by observing its
candle power it may be determined whether the resistance of the first lamp
has changed.
Dated this 8th day of February 1884.

page_text: <
I THOMAS JOHN HANDFORD of 42 Southampton Buildings in the County of
Middlesex Patent Agent, do hereby declare the nature of this Invention for
IMPROVEMENTS IN MEANS FOR INDICATING VARIATIONS IN ELECTRIC CURRENTS
OR REGULATING ELECTRICAL APPARATUS" and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement:-
The object of the said Invention is to produce an efficient apparatus for
indicating variations of electro-motive force in an electric circuit, preferably for
use in connection with systems of electrical distribution to show the changes in
pressure in the various parts of the district.
The apparatus is also capable of use in automatically regulating the electro-
motive force to correspond with such variations..
My foreign correspondent has discovered that if a conducting substance is
interposed anywhere in the vacuous space within the globe of an incandescing
electric lamp, and the said conducting substance is connected outside of the lamp
with one terminal, preferably the positive one, of the incandescing conductor, n
portion of the current will when the lamp is in operation, pass through the
shunt circuit thus formed which shunt includes a portion of the vacuous space
within the lamp.
This current is found to be proportional to the degree of incandescence of the
conductor, or candle power of the lamp."
Now the said Invention consists in the utilization of this discovery for indicating
or regulating variations in electro-motive force or for 'affecting electrical apparatus
in any desired manner.
By connecting a device for indicating current changes in the shunt circuit,
changes in the candle power of the lamp and consequently in the electro motive
force of the source of supply are made apparent; or if instead. of an indicating
device, the variations in electro-motive force are made to affect circuit controlling
apparatus, automatic regulators or other electrical apparatus may be controlled
thereby.
:
In applying the said Invention to a system of incandescing electric lighting
a standard lamp is employed having within its globe a piece of platinum by
preference a thin plate, though platinum wire may be used, placed preferably
between the limbs of the carbon conductor, the lamp terminals being connected
similarly to those of the other lamps of the system, and an additional connection
being made from the positive terminal, preferably, of the lamp circuit, to one
terminal of a galvanometer or other indicator and from the platinum piece through
a wire sealed in the glass to the other terminal of the galvanometer or indicator:
This brings the galvanometer into a shunt which includes the vacuous space
within the lamp globe.
The galvanometer, if one is used, is provided with a torsional device for holding
its needle at zero under a normal current so that variations above or below the
normal, deflect the needle in one direction or the other..
If the electro-motive force in the system, and consequently the candle power of
the lamps, increases, the indicating lamp varies with the rest and the current
from it to the galvanometer is increased, causing the deflection of the galvanometer
needle and conversely a decrease in electro-motive force in the system produces
an opposite deflection.

page_text: The galvanometer needle may be made to close circuit to electrically operated
devices for accomplishing the automatic regulation of the generator, supplying
current to the system, or for any other purpose.
An adjustable resistance may be placed in circuit with the indicating lamp to
maintain the circuit at the standard lamp resistance.
A second indicating lamp may be placed in a shunt around the one constantly
in use and may be thrown into circuit occasionally so that by observing its
candle power it may be determined whether the resistance of the first lamp has
changed.
And in order that the said Invention may be perfectly understood I shall
now proceed more particularly to describe the same and for that purpose shall
refer to the several Figures on the accompanying Sheet of Drawings the same
letters of reference indicating corresponding parts in all the Figures.
Figure 1 of the accompanying Drawings is a diagram of the system, and
connections, with a view in perspective of the galvanometer employed in carrying
out the said Invention.
Figure 2 is a diagram of a modified arrangement.
Figure 3 is a view showing the use of the galvanometer to close, regulating or
other circuits and
Figure 4 is a view of the indicating lamp herein before referred to.
Referring to Figure 1 of the Drawings 1, 2, are main conductors of a system of
electric lighting, and a a electric lamps connected across them in multiple-arc
circuits 3, 4. A is a lamp similarly connected, and similar in every way to the
other lamps, except that it has a piece of platinum b placed between the limbs of
its incandescing conductor, while a wire 5, attached to said platinum is sealed
in the glass of the globe with the wires 3, 4. (See detail Fig. 4.) The wire 5
leads to the binding post c (Fig. 1) while a wire 6, connected with the positive
wire 3 of the lamp leads to the binding post c¹.
These binding posts are the terminals of a galvanometer, which consists of
coils dd; and a needle e carried by a torsion wire f. The parts are held in
a frame B.
The upper cross bar of the frame is split at g, the split being held together by
screwshh and the torsion wire is attached to the smooth stud i which is held
by friction in the split its torsion being adjusted by turning the thumb nut j.-
A spring is attached to the other end of the torsion wire serving to keep said
wire stiff, and the tension of the spring is adjusted by means of the screw L.
A pointer m'extends from the needle to indicate its variations upon a scale n.
The torsion of the wire f is so adjusted as to hold the needle and the pointer
centrally with a normal current, that is when the lamps of the system are at
their normal candle-power; and as previously explained, any variations in the
electro-motive force of the system causing changes in the candle power of the lamps
will produce deflections of the galvanometer needle, which deflections will be
indicated on the scale.
Instead of simply causing the variations to be indicated on the scale a circuit
controlling arm o (Figure 3) may be carried by the needle e which arm may close
circuit at contacts p, or in any other suitable manner, to electrical devices for
automatically regulating the electro-motive force of the system to electrically
operated indicating devices or to any electrically operated apparatus.
An adjustable resistance C (Figure 1) may be placed in circuit with the lamp A
to maintain the said circuit at the standard lamp resistance.
In Figure 2 a-lamp A¹ is shown placed in a shunt around the lamp A. The
lamp A being constantly in use lamp A' is occasionally placed in circuit instead, so,
by observing its candle power, it may be determined whether or not the resistance
of the lamp A has changed. In the condition of the parts represented in the
Drawings the lamp A is in circuit and the lamp A¹ out of circuit. By breaking
contact however of the spring q at r and making contact at s the lamp A¹ will be
thrown into the circuit and the lamp A be cut out of circuit,

page_text: Having now particularly described and ascertained the nature of the said
Invention and in what manner the same is to be performed, I declare that what
I claim is:-
The employment in or for indicating variations in electric currents or regulating
electrical apparatus, of an incandescing electric lamp having in addition to its
incandescing conductor, a conducting body in the vacuous space within its globe
connected with the circuit outside of the lamp, whereby the current traversing the
vacuous space may be noted or the electrical apparatus accordingly regulated
substantially as hereinbefore described.