Improvements in Electric Condensers for Use in Polyphase and Multiphase Alternating Current Circuits.
Year: 1895

page_text: Date of Application, 6th Aug.. 1895-Accepted. 7th Sept.. 1895
Improvements in Electric Condensers for Use in Polyphase and
Multiphase Alternating Current Circuits.
A communication by CHARLES S. BRADLEY, of Avon, in the County of
Livingston and State of New York, United States of America, Electrical
Engineer.
1, WILLIAM PHILLIPS THOMPSON F.C.S., M.I.M.E., of The Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool, and 6 Bank Street,
Manchester, both in the County of Lancaster, 118 New Street, Birmingham in
the County of Warwick and 31 High Holborn in the County of Middlesex,
Civil 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:-
The object of the invention is to produce a compact condenser for use in
polyphase or multiphase alternating current circuits which may be handled as an
unitary device; a further object is to cheapen the construction of the condenser by
giving it an equal capacity with fewer plates than would be required in a set of
ordinary condensers when separate ones are placed between the several pairs of
poly phase alternating current mains or leads.
In carrying out the invention, metal sheets, plates or surfaces are placed side
by side as in a pile, with any suitable intervening dielectric, and a set of plates for
each lead are connected in multiple. In a triphase circuit, for example, there are
three sets, the first, fourth, seventh, etc. plate; the second, fifth, eighth, etcetera ;
and the third, sixth, ninth, etcetera, leading respectively to terminals adapted for
connection with the several leads of a triphase circuit.
The several features of novelty of the invention will be more particularly
bereinafter described, and will be definitely indicated in the claims appended to
this Specification.
Figure 1 is a diagram illustrating a condenser connected with a triphase circuit
in accordance with the invention;
Figure 2 is a diagram showing a detail of construction.
A series of plates or metallic surfaces are placed in close juxtaposition, as by
piling them one upon another with a solid intervening dielectric, or by supporting
them side by side with spacing strips so as to leave open spaces for a liquid or
gaseous dielectric, in ways familiar to those skilled in the art of making condensers.
The plates are in number a multiple of the number of leads in the supply or
distribution circuit; for example, in a triphase circuit, as exemplified in the
drawing, the number of plates are a multiple of three, and the successive plates are
connected in order with the three mains. The first, fourth, seventh, etcetera, are
connected with one lead, as a; the second, fifth, eighth, etcetera, with b; and the
third, sixth, ninth, twelfth etcetera with c. Each plate is provided, as usual, with
an ear or lug of metal projecting from the pile, the ears for the three sets being
formed so that when assembled they will lie in the same plane, to facilitate making
connection with a terminal or binding post, as seen at a, b, c, Figure 2. With this
organization a great saving of material is effected, resulting in a great increase of
capacity bulk for bulk as compared with a set of independent condensers. For
example, in the organization illustrated, there are four effective sets of plates
although but twelve plates are used in all. With a separate condenser between

page_text: each pair of leads, which is the common practice, it is evident that to get the same
number of sets and the same effective surface, twenty-four plates must needs be
employed, eight in each condenser. Moreover, the condenser is rendered far more
compact, and is greatly cheapened in construction, since but one housing or case is
required where three are necessary with the common construction. It will be
understood, also, that the condenser, by reason of its small comparative bulk may
be more easily stored in the base of a translating device, a motor for example,
with which it is to co-operate. The several current phases are distributed among
the plates in the same inanner as they are among the line wires which carry the
currents.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I declare that what I claim is :-
1. A polyphase condenser comprising a series of conductive plates or surfaces
connected in groups with polyphase terminals, the members of said groups being
interleaved with one another.
2. A polyphase condenser comprising a series of conductive surfaces electrically
connected respectively in consecutive order with three or more terminals
corresponding to the leads of a polyphase alternating current circuit.
3. A polyphase condenser comprising a series of conductive plates or surfaces
separated by a suitable dielectric and provided with terminals for connection with
a polyphase circuit, said terminals being electrically connected respectively in
consecutive order with the several plates.
Dated this 3rd day of August 1895.
WM. P. THOMPSON & Co.,
Agents.