Improvements in or appertaining to the Charging and Working of Accumulators in Electric Light Installations and the like.
Year: 1890

page_text: Date of Application, 24th May, 1890
Complete Specification Left, 24th Feb., 1891-Accepted, 28th Mar.,
1891
PROVISIONAL SPECIFICATION.
Improvements in or appertaining to the Charging and Working of
Accumulators in Electric Light Installations and the like.
I, ARTHUR BROMLEY HOLMES, of 36, Princes Avenue, in the City of
Liverpool, Electrical Engineer, do hereby declare the nature of this invention to
be as follows:-
:-
This invention has for its object a method and apparatus by which a range of
accumulators used in combination with an electric supply system can be charged by
means of a dynamo working at the electric pressure required for that system and
while actually supplying that system, and by this means avoiding the use of a
special dynamo working at a higher pressure than the general pressure of the
system.
In carrying out my invention I divide the entire range of accumulators into two
parts and couple the two in parallel circuit with the dynamo or supply mains
adding resistance coils or their equivalent sufficient to reduce the charging current
as required. When the accumulators are required for service the two half sets of
accumulators are again connected at the same time cutting off the resistance coils
and connections.
Dated thin oond day of Mar 1900
Wm. P. Thompson & Co.,
6, Lord Street, Liverpool, Patent Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in or appertaining to the Charging and Working of
Accumulators in Electric Light Installations and the like.
1, ARTHUR BROMLEY HOLMES, of 36, Princes Avenue, in the City of
Liverpool, 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 :-
This invention relates to the charging and working of electric accumulators,
especially such as are employed in connection with electric supply installations. It
has for its object a method and apparatus by which one or more ranges or batteries
of accumulators, used in combination with an electric supply system, can be
charged by means of a dynamo or dynamos working at the electric pressure
required for, and while actually supplying that system, thereby avoiding the use of
a special dynamo or dynamos working at a higher pressure than the general
pressure of the system.
In carrying the invention into effect, I divide the entire battery or batteries of
accumulators into two or more parts, sets, or groups, each containing, preferably,
an equal number of cells, and I couple the said two or more groups in parallel
circuit with the dynamo or supply mains, adding in each charging circuit, if
necessary, a resistance coil or its equivalent, so arranged and proportioned as to
reduce the charging current to the required pressure.
The drawing shows how the invention may be applied to two ranges or batteries
of accumulators connected in parallel with the main circuit.
A B are the two batteries each supposed to consist of 60 cells a, b, connected in
series, only a few being, however, shown. CC is the main working circuit, to
which the batteries are connected in parallel by connections a' a³ and b¹ b

page_text: respectively. For charging, the 120 cells composing the two batteries are divided
into three sets or groups DEF of 40 cells each, as shown. Each group is
connected with the main circuit CC by the charging maing d d'ee and f
respectively, each of which is connected in circuit with a resistance coil R, so
proportioned that the pressure of the electric current is reduced to the proper
amount for charging the accumulators.
To take an example 'by way of illustration; suppose the working current to
have a pressure of 120 volts and that each battery of 60 cells requires a pressure
of 150 volts to fully charge it. To charge each group of 40 cells a pressure of
100 volts is necessary but as the main pressure is 120 volts, the resistance coils
must each be so proportioned as to absorb 20 volts, this representing the loss:in
charging. In a similar manner if three batteries, of 60 cells each, be subdivided
into four groups of 45 cells each, the loss in charging would be represented by
8 volts and so on, the loss decreasing as the ratio of the number of cells in each
group to that of the cells in each battery increases. I am thus enabled to charge
the accumulators, without the use of a special dynamo, while the general supply
circuit is in operation, and that with a comparatively small, loss of electric
energy.
When the accumulators are required for service, the groups are again formed
into a battery or batteries and connected directly with the mains, the resistance
coils and charging connections being at the same time cut out.
The discharging connections or switches are marked S¹ and the charging
connections or switches are marked S on the drawing. As the connections for
charging and discharging must not be made at the same time, I prefer to use a
rocking switch or similar device by which one set of connections is broken, and the
other set made in succession, any suitable connections or switches may, however,
be employed.
Each group of cells can be charged independently of the others and in this way
the load in the dynamo due to charging the accumulators may be increased or
decreased to compensate for any decrease or increase in the current required for
the general supply system. By this means it is possible to work the dynamo
always at its highest efficiency.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. The method of charging and working a battery or batteries of accumulators
used in connection with an electric supply system, by arranging the cells for
charging, in two or more groups connected in parallel with the supply circuit, each
of said groups having, if necessary, a resistance device to reduce the pressure to
that required for charging the accumulators, substantially as described.
2. The improved arrangement of accumulators, resistances and connections,
taken as a whole substantially as shown and described, whereby the accumulators
may be charged by a dynamo or dynamos feeding the supply system and working
at the normal pressure of that system and whereby such dynamo or dynamos may
be worked always at or near their maximum efficiency.
Dated this 27th day of February 1891.
WM. P. THOMPSON & Co.,
Of Liverpool, Manchester, Nottingham, and London, Patent Agents.