IMPROVED APPARATUS FOR MEASURING AND RECORDING ELECTRICAL ENERGY
Year: 1884

page_text: I, FREDERICK WALKER 86 Spondon Road Tottenham Middlesex Engineer do
hereby declare the nature of my invention for IMPROVED APPARATUS FOR MEASURING
AND RECORDING ELECTRICAL ENERGY to be as follows:-
The apparatus according to my Invention consists of a cylinder driven by
suitable clock work, having a sheet of paper wrapped tightly round its outer
surface. Two solenoids one wound with thick wire, through which the whole
current passes, and the other with fine wire of high resistance, in shunt. Each of
these are fitted with an iron core, held in position by means of springs. So, when
a current is passing through the low resistance solenoid the core is drawn into it
against the tension of the spring, in a degree proportional to the current. The core
of the other solenoid is depressed in proportion to the Electromotive force. Two
arms are attached to each of these cores, carrying pencils, which, pressing upon the
paper on the revolving cylinder, describes two curves the sum of which at any
period represents the electrical work done in the circuit.
The paper upon the revolving cylinder is ruled vertically, the space between
each line being traversed within an hour or half hour, and a proper scale being
provided for each spring so that the ordinates may be read off in volts and ampères,
when the paper is removed from the cylinder and laid flat.

page_text: COMPLLIE
DIEULICATION.
I FREDERICK WALKER of 36 Spondon Road, Tottenham, in the County of
Middlesex, Electrical Engineer, do hereby declare the nature of my Invention for
IMPROVED APPARATUS FOR MEASURING AND RECORDING ELECTRICAL ENERGY,
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 my Invention is the production of an arrangement of electric
energy measuring and recording apparatus or instrument (or "Electric Meter") by
the adoption of which, the working of said instrument is plainly and legibly
recorded in the shape of a diagram upon paper or other suitable material. Said
recorded result is "taken" or read at once from the diagram thus obtained,
instead of involving the calculations and deductions necessary with meters of the
dial" and other types hitherto introduced.
"
The instruments or apparatus according to my Invention may be used either for
electrical testing in the laboratory or as current or energy meters in electric light
or power circuits.
The principle embodied in the device or contrivance according to my Invention
is based upon the derivation of the electro-magnetic unit of power, commonly
called the "Watt," which is the product of the unit of electro-motive force-namely
one Volt multiplied by the unit of current,-namely one Ampère :—, said "Watt "
being thus equal to 44-24 foot pounds per minute. Therefore I contrive that a
sheet of paper or other suitable material shall revolve in front of, or otherwise be
caused to advance in front of, and in contact with, a stylus, pen, or pencil; the rate
of travel, or progress of said sheet of paper or other material employed, corresponding
to the proportional time factor of the reading.
I arrange as forming part of the device or contrivance according to my Inven-
tion a system of double solenoids in such a manner that one of low resistance is
included in the main circuit, which is to be measured, in "series.". The magnetic
action of said solenoid is caused to operate the stylus, pen or pencil aforesaid in a
direction at right angles to the plane of motion of the paper or other material.
Now, as the magnetic force of a solenoid varies as the number of convolutions of
wire surrounding it or the current flowing through such a wire, the number of
turns or convolutions of wire are, in the arrangement of apparatus according to my
Invention, constant; the variation of current must therefore produce a corre-
sponding variation of the lever carrying the stylus, pen or pencil, and so cause the
double movement of the paper and stylus, or equivalent, to imprint a curve which
is proportional to the current flowing in the circuit; the ordinates of said curve
forming the time factor and the height of the curve correctly indicating the
quantity passing in the circuit. Similarly I arrange upon the same instrument
aforesaid another solenoid in "shunt" with the main electrical circuit, and of such
bigh resistance in proportion to the external resistance of the circuit, that a
variation of the latter produces but an imperceptible change or variation of the
magnetic force of said second solenoid. I also arrange a second stylus or equivalent,

page_text: in such a manner as to ensure that the fluctuations of the magnetism of the second
solenoid aforesaid produces a second curve upon the moving paper, or equivalent,
herein before referred to, the dimensions of which curve are proportional to the
electromotive force existing in the circuit, inasmuch as any variation in a solenoid
of such high resistance must be due to electro-motive force alone. It follows
therefore; that the sum of the two curves aforesaid, at any ordinate, will be equal
to, and represent the electrical energy expended in the circuit.
In order that my said Invention may be the better understood, I have appended
the accompanying sheet of drawings illustrative of same, and in the several views
of which, the same letters of reference are employed to denote like or corresponding
parts throughout. I will first refer to Figures 1 and 2 which represent a side
elevational view and end view respectively of one arrangement or type of instrument
or apparatus according to my Invention, A being the cylinder herein before men-
tioned surrounded with paper or other material as aforesaid; said cylinder being
caused to rotate by suitable clockwork, or other motion. B is the solenoid of low
resistance, fitted with a loose core of soft iron D, to which is attached the lever b
carrying the stylus or equivalent e, C is the solenoid of high resistance aforesaid,
also fitted with a loose core D of soft iron to which is attached the lever a carrying
a stylus or equivalent e. The "pull" of the solenoids upon their respective cores
tends to contract a spiral spring c of guaged tension, fitted to each solenoid. The
instrument is provided with a scale, graduated or divided to suit the tension of the
springs c aforesaid, so as to allow of the value of the height of the curve above the
datum or zero line being taken in volts and ampères, or the sum of the two curves
in "Watts"; and the screwed nuts & serve for the adjustment of the stylus or
equivalent to the zero or datum line above referred to.
For special cases where the actual electrical energy is to be measured directly
and such measurement to be recorded, I arrange the two solenoids as shown in
Figures 3 and 4 by a sectional and an end elevational view respectively. In this
case the solenoid of low resistance, B is coupled in "series" with the main circuit
and is wound with an insulated strip preferably of copper, alternate layers of which
are coupled in "parallel" or in "series" according to the current strength for which
the instrument is adapted, but such coupling always being arranged so that the
polarity of each layer of copper strip (or wire as the case may be) is of similar sign.
The orifice of the low resistance solenoid B is of sufficient diameter to allow of the
smaller solenoid C-namely that of high resistance-being freely passed within B;
and, said high resistance solenoid C is coupled in "shunt" to the main circuit.
A fixed soft iron core D¹-preferably laminated-is placed centrally within B in
such a manner that the solenoid C enters upon it, to say, one fifth of its length
when at its maximum height out of the solenoid B. Attached to the cap of
solenoid C is a guide stud, with adjusting nut d which latter presses upon the guaged
spiral spring c the other extremity of which spring rests upon the crosspiece g
above the moveable solenoid C aforesaid. The tension of said spring c tends to
keep the solenoid C out of the solenoid B, the degree of such tension always being
regulated by the nut d; and, a lever a¹, fulcrumed at f carrying the stylus e is
operated by a suitable sliding arrangement attached to the solenoid C, so that upon
the descent of the latter into the solenoid B, against the tension of the spring c, the
stylus e is raised to a height above the zero or datum line, proportionate to the
counterstrain set up by the magnetic effect of the current, and delineates upon the
paper surrounding the cylinder A, a curve, corresponding to such counterstrain.
The action of the last described arrangement of the apparatus according to my
Invention is as follows.-The number of convolutions of the copper strips, or of the
wire upon B being constant the magnetic effect of said solenoid coupled in "series"
varies directly as the current passing through the circuit, and so exerts a pull
upon C and therefore causes a corresponding movement of the lever a¹. Similarly
the magnetic effect of the current passing round the solenoid C is directly propor
tional to the electro-motive force existing in the circuit, and I also contrive that
the polarity of said solenoid C shall be of opposite sign to that of B, in order that

page_text: the motion of the lever a¹ shall be equal to the sum of the two forces, that is to
say, that the magnetic pull of the solenoid B, upon C, shall correspond to current
strength and the magnetic pull of C upon the fixed iron core D¹, which is polarised
by the inductive action due to solenoid B as well as its tendency to enter B by
reason of its polarity, shall represent a pull corresponding to electromotive force.
The spriral spring c (shewn more fully in Figure 4) is of suitably guaged tension,
and the resultant force of the magnetism induced by the current in the two
solenoids B and C respectively, acts against the tension of said spring, and therefore
the movement of the stylus or equivalent being increased,-owing to its lever being
of unequal length on either side of the fulcrum f--is proportionate to the electro-
motive force of the current in the main circuit multiplied by the quantity of said
current. In other words the curve registered by the stylus is proportional to the
electrical power developed within the circuit and may be measured by a suitable
scale graduated correspondingly to the tension of the spring c-in Volts, Ampères,
"Watts
or any other electrical units which it may be found convenient to adopt.
I wish it to be understood that in special cases where the external resistance of
the electrical circuit is very high, and is subject to considerable variation, I may
add to the herein before described parts, an auxiliary resistance coil, or series of
such coils, of german silver wire, or other wire possessing a high specific resistance.
Said coil or coils would be included in the "shunt" circuit of the solenoid C so as
to raise the resistance of such shunt to a sufficient degree to render the magnetic
effect of C upon the lever a or a¹, (as the case may be) dependent upon the
electromotive force of the circuit alone, and consequently that the effect of an
alteration of the resistance of the external circuit shall be of negligible value in the
resultant curve.
"
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is
Firstly: The employment of solenoids acting upon a stylus or equivalent so as
to describe a curve upon a moving sheet of paper or other material, such curve
being proportional to the factor of quantity and that of electro-motive force of an
electrical circuit to be measured.
Secondly: The arrangement of double solenoids with fixed core substantially as
herein described in reference to Figures 3 and 4, in connection with a lever and
stylus or equivalent for describing upon moving paper or other material a curve
which is proportional to the electrical energy developed within a circuit during a
given time.