Improved Means for Charging Accumulator Batteries on Electric Circuits Supplied by Current Generators.
Year: 1890

page_text: Date of Application, 7th Nov., 1890
Complete Specification Left, 23rd July, 1891-Accepted, 29th Aug., 1891
PROVISIONAL SPECIFICATION.
[Communicated from abroad by Messrs. SIEMENS & HALSKE, of Berlin, in the
German Empire, Electrical Engineers.]
Improved Means for Charging Accumulator Batteries on Electric
Circuits Supplied by Current Generators.
We, SIEMENS BROTHERS & Co. LIMITED, of 12 Queen Anne's Gate,
Westminster, in the County of Middlesex, Electrical Engineers, do hereby declare
the nature of this invention to be as follows:
The use of accumulators for assisting or temporarily replacing an electric current
generator is subject to the difficulty that the accumulators require for charging
them a greater potential difference at their terminals than is produced by them on
discharging.
There are various means for overcoming this defect, the best known of which
consist in varying the resistance of the charging and discharging leads, in varying
the number of cells in action, or in similar devices which are operated either auto-
matically or by hand for varying the charging and discharging potential difference
at will.
The present invention relates to the use of an arrangement of auxiliary dynamo
for varying the potential difference between two charging and discharging leads in
such manner that a uniform supply to glow lamps and other current consuming
devices and a uniform charging and discharging of an accumulator battery is
rendered possible.
On the accompanying diagrammatic drawings
Fig. 1 shews the simplest arrangement for this purpose. M is the current
generator at the source of supply, the potential difference at the terminals of which
remains practically constant, and should be so adjusted as to be sufficient to feed
the lamps or other current consumers at the point of consumption L through the
conducting mains with current of the tension required by such current consumers,
but which is not necessarily sufficient for charging the accumulators A, which, in
this case are supposed to be situated at the place of consumption.
In order to provide the tension which is required from time to time for charging
the accumulators, an auxiliary dynamo is introduced at Z which can either be
driven by the motor of the dynamo M, or which may be coupled with the latter
directly or by means of belts, or which may be driven by any other means with a
constant speed. This auxiliary machine, which may be either series or compound
wound, is made to operate with such a tension as to supply the excess of tension
which is required for the charging of the accumulators.
If the discharge of the battery is to take place simultaneously into the lamp
main, a so called cell controller $ or a regulating resistance or other device must
be provided which adjusts the potential difference between those poles of the
accumulator from which the discharge takes place to the degree suitable for the
amps.
For charging the battery a special third charging main may be provided as
at Fig. 2. In this case either the charging of the accumulator and the feeding of
he lamps by the main dynamo may be separately effected, by moving the switch U
Fig. so as to disconnect the battery from the lamps, or the charging and dis-
charging of the battery can take place simultaneously as at Fig. 1 the free terminal
of the lamp main being connected to a suitable part of the battery.
Fig. 3 shews another arrangement, in which the consuming district is situated
between the dynamo and the accumulator battery. In this case the auxiliary

page_text: machine Z requires a special motor, which may be of any kind, but preferably an
electro motor which is connected to the charging mains.
Either the exciting curient of the motor or the auxiliary dynamo can in this
case be so regulated that the potential difference of the latter is sufficient for
effecting the increase of tension in the charging mains requisite for charging the
accumulator.
Fig. 4 shews the application of the described arrangement for a complete system
of distribution. In this case C is a central station from which the two accumu-
lators A' and A³ can be charged, which latter discharge into the distributing
mains. When the load of two such secondary distributing stations A' and A² is
different during the discharging, both batteries will require quite different tensions
for charging them. If in that case there were no provision such as above
.described, an automatic equalisation of tension would be effected between the
several stations, which would have the effect that not only would the accumulator
that for the time being had the lowest tension, alone receive current from the
dynamo, but it would also take current from the other batteries. In applying in
this case the auxiliary dynamos Z' and Z2 to the batteries A' A² they can, by
adjustment of their shunt resistances, be brought respectively to such a potential
difference that any such before mentioned equalisation of the tension in con-
sequence of a discharge through the discharging mains cannot take place, and
that each separate battery shall be charged with its own special tension.
Dated this 7th day of November 1890.
ABEL & IMKAY,
Agents for the Applicants.
COMPLETE SPECIFICATION.
Improved Means for Charging Accumulator Batteries on Electric
Circuits Supplied by Current Generators.
We, SIEMENS BROTHERS & Co. LIMITED, of 12 Queen Anne's Gate,
Westminster, in the County of Middlesex, Electrical Engineers, 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:
The use of accumulators for assisting or temporarily replacing an electric current
generator is subject to the difficulty that the accumulators require for charging
them a greater potential difference at their terminals than is produced by them on
discharging.
There are various means for overcoming this defect, the best known of which
consist in varying the resistance of the charging and discharging leads, in varying
the number of cells in action, or in similar devices which are operated either auto-
matically or by hand for varying the charging and discharging potential difference
at will.
The present invention relates to the use of an arrangement of auxiliary dynamo
for varying the potential difference between two charging and discharging leads in
such manner that a uniform supply to glow lamps and other current consuming
devices and a uniform charging and discharging of an accumulator battery is
rendered possible.
On the accompanying diagrammatic drawings
M is the current
Figure 1 shews the simplest arrangement for this purpose.
generator at the source of supply, the potential difference at the terminals of which
remains practically constant, and should be so adjusted as to be sufficient to feed
the lamps or other current consumers at the point of consumption L through the
conducting mains with current of the tension required by such current consumers,
but which is not necessarily sufficient for charging the accumulators A, which, in
this case are supposed to be situated at the place of consumption.

page_text: In order to provide the tension which is required from time to time for charging
the accumulators, an auxiliary dynamo is introduced at Z which can either be
driven by the motor of the dynamo M, or which may be coupled with the latter
directly or by means of belts, or which may be driven by any other means with a
5 constant speed. This auxiliary machine, which may be either series or compound
wound, is made to operate with such a tension as to supply the excess of tension
which is required for the charging of the accumulators.
If the discharge of the battery is to take place simultaneously into the lamp
main, a so called cell commutator S or a regulating resistance or other device must
0 be provided which adjusts the potential difference between those poles of the
accumulator from which the discharge takes place to the degree suitable for the
lamps.
For charging the battery, a special third charging main may be provided as at
Figure 2. In this case either the charging of the accumulator and the feeding of
the lamps by the main dynamo may be separately effected, by moving the switch U
Figure 2 so as to disconnect the battery from the lamps, or the charging and dis-
charging of the battery can take place simultaneously as at Figure 1 the free
terminal of the lamp main being connected to a suitable part of the battery.
Fig. 3 shews another arrangement, in which the consuming district is situated
between the dynamo and the accumulator battery. In this case the auxiliary
machine Z requires a special motor, which may be of any kind, but preferably an
electro motor which is connected to the charging mains.
Either the exciting current of the motor or the auxiliary dynamo can in this
case be so regulated that the potential difference of the latter is sufficient for
effecting the increase of tension in the charging mains requisite for charging the
accumulator.
Fig. 4 shows the application of the described arrangement for a complete system
of distribution. In this case M is a central station from which the two accumu-
lators A' and A² can be charged, which latter discharge into the distributing
mains. When the load of two such secondary distributing stations A' and A² is
different during the discharging, both batteries will require quite different tensions
for charging them. If in that case there were no provision such as above
described, an automatic equalisation of tension would be effected between the
several stations, which would have the effect that not only would the accumulator
that for the time being had the lowest tension, alone receive current from the
dynamo, but it would also take current from the other batteries. In applying in
this case the auxiliary dynamos Z' and to the batteries A' A² they can, by
adjustment of their shunt resistances, be brought respectively to such a potential
difference that any such before mentioned equalisation of the tension in consequence
of a discharge through the discharging mains cannot take place, and that each
separate battery shall be charged with its own special tension.
Figs. 5 and 6 shew other modifications, the object of which is as follows. When
a number of current consuming apparatus are arranged parallel with each other
in connection with the accumulator battery through the medium of a cell coni-
mutator, which has the duty of maintaining constant the potential difference at the
terminals of the current consumers, such duty of the cell commutator can be
divided into two parts.
Firstly, it serves to compensate for the loss of potential difference in the leads,
according to the number of the consuming apparatus which are included at one and
the same time in the circuit, and secondly it has to prevent the production of
variations in the potential difference at the terminals of the consuming apparatus,
by any occurring variations in the electromotive force of the cells.
The arrangement shewn at Fig. 5 has for its object to cause the second above
lescribed function to be entirely carried out by the auxiliary machine Z.
For this purpose, the dynamo M being made always to produce a constant
potential difference, the machine Z is so arranged that in the branch in which
he battery is situated, that is to say, between the points C and B, there shall

page_text: always exist the necessary charging potential difference of the accumulator
battery X.
Between the points D and B between which the lamps are situated,
there will then always exist the potential difference of the machine M, and the
cell commutator S is only used for compensating for the loss of potential difference
always occurring in the leads L, Lig
The diagram Fig. 7 serves to elucidate this mode of action. The ordinates upon
the horizontal line D B represent absolute potentials. Between the points D and B
are placed the leads L, L. and the lamps, and these receive the constant potential
difference of the machine M, which is represented by the difference between the
potentials at the points D and B, that is to say between the quantities D D¹ and
Between D and C is placed the auxiliary machine Z, producing the potential
difference represented by the difference between the potentials at the points D
and C, that is to say, between the quantities D D and C C¹.
zero.
The battery is situated between the points C and B and is subject to a potential
difference, which is represented by the difference between the potentials at the
points C and B, that is to say, between the quantities C C and zero. The battery
consequently alone receives the sum of the potential differences of the machine M
and the machine Z, the lamps being subject to the potential difference of the
machine M only. The point B and the dotted lines leading to B₁ represent the
variations which can be produced by the cell controller.
This arrangement offers no particular advantages over those previously described
so long as only a single accumulator battery has to be worked from the current
generator M.
In such a case the arrangement described with reference to Figure 2 can be used
with as good an effect, inasmuch as for compensating for the losses of potential
difference in the leads, the potential difference of the machine M can be corre-
spondingly regulated.
This is however not possible when several batteries are worked from one and the
same current producer M, because in that case the variations of potential difference
will be different in the several circuits. In that case it will be of advantage to
employ the last described arrangement, as, for example shewn in the diagram
Fig. 6. This arrangement differs from that shewn at Fig. 4 in that, in the branch
leads in which the batteries X are situated, the cell commutators S' S³ are not
arranged between the batteries X'X' and the auxiliary machines Z1 Z2, but either
the battery, for example X is situated between the cell commutator S¹ and the
auxiliary machine Z' or the auxiliary machine, for example Z2, is arranged between
the cell commutator S2 and the battery X².
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 combination with a dynamo electric machine and an accumulator battery,
in which the terminal potential-difference of the former, and the discharge potential-
difference of the latter are made to correspond with the required current supply
for one and the same number of lamps or other current consumers, the use of an
auxiliary dynamo machine so arranged that its terminal potential difference is
added to that of the first named dynamo machine in such manner as to produce,
at those points between which the accumulator battery is placed, the potential
difference requisite for charging the battery, regard being had to the existing
resistances of the circuit and the required charging current, substantially as
described.
2. Arranging the combination referred to in the preceding claim in a distributing
system for electrical energy in such manner, that any desired number of accumu
lator batteries are provided with auxiliary machines, so that the batteries can be
charged independently of each other by means of one and the same dynamo
machine, or by several machines coupled in parallel, the strength of the charging
current being capable of regulation, substantially as described.

page_text: 3. Arranging the combination referred to in the first claim in connection with
accumulator batteries having cell commutators in such manner that either the
auxiliary machine is situated in the branch circuit of the accumulator battery,
between the latter and the cell or that the accumulator battery is situated between
the cell commutator and the auxiliary machine, substantially as and for the purposes
described.
Dated this 22nd day of Iml
1001
ABEL & IMRAY,
Agents for the Applicants.