Year: 1888

page_text: We ROBERT PERCY SELLON of 112 Belvedere Road Lambeth in the County of
Surrey Electrical Engineer and ROBERT CATTLEY JACKSON of Firths Hotel Salisbury
Street Strand in the County of Middlesex Electrical Engineer do hereby declare the
nature of this Invention to be as follows:-
Our Invention relates to meters for the purpose of indicating and registering or
recording the passage of currents of electricity.
According to our Invention we actuate indicators and registers or recorders by
action due to the gas or gases resulting from the electrolysis of liquid by the current
or part of the current to be metered and periodically exploding the resulting gas or
gases or permitting the escape thereof.
The pressure of the gas or gases is utilized to give motion to an indicator and
register or recorder which may be effected by any suitable device such for example
as by a piston or float or by closing electric circuits to actuate electro-magnetic
devices.
1
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London,
Agents.

page_text: We ROBERT PEROY SELLON of 112 Belvedere Road Lambeth in the County of
Surrey Electrical Engineer and ROBERT CATTLEY JACKSON of Firth's Hotel Salisbury
Street Strand in the County of Middlesex Electrical Engineer do hereby declare
the nature of this invention and in what manner the same is to be performed to be
particularly described and, ascertained in and by the following statement :-
Our invention relates to meters for the purpose of indicating or registering the
passage of currents of electricity.
Under our invention we actuate the indicating or recording apparatus of electricity
meters by the electrolysis of a liquid such as acidulated water or of acid, or alkaline
solutions with or without metallic salts dissolved therein the said liquid being con-
tained in closed vessels, the pressure of the gas or gases set free by electrolytic action
being caused to give motion to a float or diaphragm enclosed within or constituting
a portion of the said closed vessel which motion by causing an electric circuit to be
closed ignites or explodes the gas or gases so set free. The gas (or gases) recom-
bines or condenses to the liquid form and the cycle is repeated so long as the current
to be metered is passing in-the circuit. In the electric circuit by which ignition_or
explosion is effected we place an electro magnet which upon the circuit being closed
as above described operates an armature attached to the counting or recording
mechanism or the counting or recording mechanism may be operated directly from
the moving diaphragm or float or through mechanism connected therewith.
To provide against variation of resistance due to variation of temperature we may
use a metallic or other suitable resistance so proportioned that the effect of varying
temperature on the electrolyte is balanced by its effect on the resistance.
The accompanying drawings show what we consider the best means of carrying our
invention into effect.
In Figure 1 (which is a vertical-section) A is a U tube which may conveniently.
be of glass but may be of any other material not injuriously acted upon by or acting
on the liquid which it contains one limb being preferably longer than the other as
shown. The end B. of the tube is closed in any convenient way. In the drawing
it is shown as being.closed by means of a cap C screwed to a collar C₁ cemented or
otherwise secured to the tube A. Between the cap () and the collar C we place an
elastic washer C for the better closing of the joint. Through the cap C are led
insulated wires D D to which a small spiral of platinum D³ or other relatively non
fusible wire is attached. Instead of using the cap C the wires D D may be sealed
directly into the glass the top of the tube being closed by fusion and similarly the
explosion of the gases may be effected by a spark from an induction coil or otherwise
and passing between two wires fused into the glass or passing through the cap C.
At E the electrodes conveying the current to the electrolyte are passed into and
fused or otherwise secured in the tube A.
The other end of the tube A is closed by a diaphragm F flexibly connected to the

page_text: tube A so as to be capable of moving without interfering with the closure of the tube.
India rubber is a suitable material for this connection and also for the diaphragm. To
this diaphragm a metallic contact piece F¹ is securely attached.
A spring F held against a stop F returns the diaphragm F to its normal position.
The piece F' is brought into contact with the contact piece G upon the movement
of the diaphragm due to the generation of gas or gases thereby closing the circuit of
the exploding or igniting device D' and so causing condensation or recombination of
the disengaged gas or gases.
An adjustable stop to check the upward movement of the diaphragm is shown
at G¹.
It is desirable to leave a sufficient column of air or other gas between the electrolyte
within the tube and the diaphragm F to allow for a compressive or cushioning action
during the working of the apparatus. This may be done by enlarging that end of the
tube A or by prolonging it as shown.
Between the electrolyte and the end of the tube on the opposite side B it is desirable
to leave a quantity of air or an inert gas sufficient to diminish the force of the
explosion or ignition.
In Figure 2-A is the tube shown in Figure 1 and M the electro magnet which
actuates the counter as hereinbefore described, K is a primary or secondary battery
in circuit with the electrolysing circuit.
A meter based on the principle of electrolysis of a liquid in the absence of some
external expedient will not commence to operate until such an electro motive force
has been attained between the electrodes as is necessary to decompose the liquid
thereby involving an undue loss of energy combined with a relatively limited working
range and therefore an accurate counting cannot be obtained without some such
external expedient.
The object of the cell K is therefore to provide a "balancing" electro motive force
to overcome these difficulties and it is therefore obvious that this cell should have an
electro motive force of itself as nearly equal as possible to that required for electrolysis
of the liquid used within the vessel A and that its internal resistance should be as
small and as constant as possible.
H is a metallic coil or other device arranged to compensate for the effects of
variation of temperature in the vessel A.
The meter is placed preferably as a shunt across some portion R S of one (T) of the
main conductors conveying the current to be indicated or registered and is so arranged
that a small portion only (say one hundredth of the total current) passes through the
meter circuit.
The action of the arrangement is as follows:-
When no current is passing in the circuit the cell K balances the electro motive
force required to decompose the liquid in the vessel A and no decomposition of the
said liquid ensues.
Upon the passage of current in the main conductors however the electro motive force
of the cell K is reinforced by the additional difference of potential between the
points R and S and decomposition of the liquid ensues. The disengaged gas or gases
collect in the upper portion B of the tube A a pressure being established thereby which
gradually depresses, the liquid in one leg of the tube A and raises it in the other leg
and so the diaphragm F is raised until contact between the pieces F' and G is made
which causes a momentary current (which may either be obtained from the shunted
portion of the main R S or from a shunt placed across both main conductors T and T¹)
to pass through the second circuit of the meter, heating the coil D³ or its equivalent
so as to cause the ignition of the gas or gases and condensation or recombination
thereof into the liquid form and at the same time magnetising the electro magnet M
so as to cause attraction of its armature N and consequent registration (by any con-
venient or well known counting arrangement) upon the recording dials P. After the
gas or gases have been ignited or exploded in the part B of the tube the consequent reduc-
tion of pressure there relieves the diaphragm of the pressure which raised it and the
parts return to their normal position to be again operated as described.

page_text: We do not limit ourselves to the use of a cell K as it will be evident that its
equivalent can be used, for example Figure 3 shows a modification of this arrange-
ment suited especially for alternating currents wherein a transformer V is shown in
substitution for the balancing cell K of Figure 2. This transformer (of which the
primary is coupled up as a shunt across the main conductors T and T and the
secondary is placed in the electrolysing circuit) provides an initial electro motive force
just as does the cell K in Figure 2. It will thus be seen that this meter can be
used for either continuous or alternating currents. When used for the latter it is
only necessary in order to obtain volumes of disengaged gas or gases which shall be
substantially proportional to the current flowing to provide for a proper ratio between
the current density at the surface of the electrodes and the rate of alternations of the
current as is well known.
We are aware that it has been previously proposed to use pressure due to electrolysis
of liquids to meter electric currents but so far as we are aware the means which have
been devised to carry out the principle have not been suitable for practical and accurate
working.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. In an electricity meter a vessel closed at both ends and containing a liquid and
means for electrolysing it and evolving gas or gases and for igniting or exploding the
gas or gases evolved and means for actuating a counter by the movement derived
therefrom substantially as hereinbefore described.
2. In an electricity meter a vessel containing a liquid and means for electrolysing
it and having an igniting or exploding device and a diaphragm or the like provided
with or operating on means for actuating a counter and for closing a circuit for
exploding or igniting the gas or gases due to electrolysis of the liquid substantially as
hereinbefore described.
3. In connection with an electricity meter operated by electrolytic action means
for balancing the electro motive force required for the said action substantially as
herein before described with reference to Figures 2 and 3 of the accompanying
drawings.
4. The arrangement and combination of parts constituting the device hereinbefore
described and shown in Figure 1 of the accompanying drawings.
5. The arrangements and combinations of parts hereinbefore described and
illustrated respectively in Figures 2 and 3 of the accompanying drawings for the
purposes described.
Dated this 7th day of Jannary 1889