Improvements in Electrical Distribution.
Year: 1892

page_text: Date of Application, 6th Oct., 1892
Complete Specification Left, 6th July, 1893-Accepted, 12th Aug., 1893
PROVISIONAL SPECIFICATION.
Improvements in Electrical Distribution.
I, THOMAS TOMLINSON, of Lynton, Durham Road, Raynes Park, in the County
of Surrey, Electrical Engineer, do hereby declare the nature of this invention to
be as follows:-
In the distribution of alternating currents for electric lighting a three wire
system is at present in use and an economy in the copper required for the electric
mains is obtained; the current being conveyed at double the voltage at which it is
required for house distribution.
By my invention I obtain the advantage of the double voltage without the
expense and inconvenience of the third wire.
generate the alternating currents by dynamos at a main station at high voltage
and I convey these currents to substations conveniently dispersed about the district
to be lighted. At each substation I provide a transformer which gives a current
at double the voltage required by the consumers.
At this double voltage I convey the current by a pair of mains to a point to
which also the low pressure or house mains are brought.
Several points may thus be supplied from one substation.
At the point in each case I provide a one to one transformer. I connect one
pole of the double voltage feeding circuit to one of the primary terminals of the
converter and the other pole to one of the secondary terminals.
I also connect
the other primary and secondary terminals by a short wire. The low pressure or
house mains are also connected with the one to one transformer, one set of house
mains being connected with the two primary terminals and another set of house
mains with the two secondary terminals.
It results from these arrangements that under all conditions, the voltage at the
primary terminals of the one to one transformer will be practically the same as the
voltage at the secondary terminals and just one half of that in the double voltage
circuit by which the one to one converter is supplied.
Dated this 6th day of October 1892.
THOMAS TOMLINSON.
COMPLETE SPECIFICATION.
Improvements in Electrical Distribution.
1, THOMAS TOMLINSON, of Lynton, Durham Road, Raynes Park, in the County
of Surrey, 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:-
In the distribution of alternating currents for electric lighting a three wire
system is at present in use and an economy in the copper required for the electric
mains is obtained, the current being conveyed at double the voltage at which it is
required for house distribution.
By my invention I obtain the advantage of the double voltage without the
expense and inconvenience of the third wire.
I generate the alternating currents by dynamos at a main station at high voltage
and I convey these currents to substations conveniently dispersed about the district
to be lighted. At each substation I provide transformers which give a current at
double the voltage required by the consumers.

page_text: At this double voltage I convey the current by a pair of mains to a point to
which also the low pressure or house mains are brought.
Several points may thus be supplied from one substation.
At the point in each case I provide a one to one transformer. I connect one
pole of the double voltage feeding circuit to one of the primary terminals of the
converter and the other pole to one of the secondary terminals. I also connect the
other primary and secondary terminals by a short wire. The low pressure or
house mains are also connected with the one to one transformer, one set of house
inains being connected with the two primary terminals and another set of house
mains with the two secondary terminals.
It results from these arrangements that under all conditions, the voltage at the
primary terminals of the one to one transformer will be practically the same as the
voltage at the secondary terminals and just one half of that in the double voltage
circuit by which the one to one converter is supplied.
-
The drawings annexed show diagrammatically my system of distribution.
a a represent dynamos at the generating station where the current is generated
at high pressure say 1000 volts or more according as the distance from the
consumers may render more or less pressure desirable. 6b are the high pressure
mains leading from the generating station to the substation. ccc indicate a series
of as many transformers as may be required and by these the mains d d are supplied
at double the service pressure say 200 volts. ee are the service mains and e¹ el
indicate lamps thereon. ff and f¹f are the coils of the one and one transformers
which I employ in the peculiar manner already stated to reduce the pressure for
the service mains. Two pairs of service mains may be led off from the one and
one transformer one pair of service mains along one side of a street to be lighted
and the other pair along the other side or such other arrangements may be made
as may be desirable to obtain as nearly an equal loading of the two pairs of service
mains as may be practicable. The one and one transformer may be of any
approved construction its only peculiarity being in the equality of the coils f
and f. The dimensions of each one and one transformer must be such as to render
it competent to convert without injury to itself a current corresponding to the
greatest difference in loading which can arise between the two pairs of service
mains with which it is connected. More than two pairs of service mains may be
connected to the same one and one transformer in which case it is the difference in
loading between the circuits on one side and the other with which the transformer
will have to deal. 99 are switches at the substation for putting the transformers
in and out so that only as many transformers c as are required to meet the demand
for current may be connected for use. hh is a telephone connection between the
generating station and the substation and ii are connections for a volt meter
indicating at the generating station the pressure in the mains d d. The connections
and i are useful adjuncts but in respect to them other arrangements may be made.
Where a generating station in the immediate neighbourhood of the consumers is
available direct connections may be made between the dynamos and the mains d d
the dynamos being in this case of suitable construction to supply a current at double
the service pressure.
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. In a system for the distribution of electricity the combination substantially as
described consisting of a one and one transformer, à double pressure feeding circuit,
and two service circuits; the feeding or double pressure circuit connected at
terminals with both coils of the transformer, the other terminals of the transformer
being coupled together and the service circuits being connected each with the two
terminals of one of the transformer coils.
2. The means for the distribution of alternating currents of electricity consisting
in generating currents at a high pressure, conveying them by high pressure mains

page_text: to a substation, transforming the currents down to double the service pressure ;
conveying these currents through intermediate mains to a one and one converter
connecting such mains with the one and one transformer so that the circuit may be
traced through the two coils of the converter in series; and connecting also two or
more service mains with the same transformer so that each service circuit may be
traced through one only of the coils.
T1002
THOMAS TOMLINSON.