Year: 1887

page_text: I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
M.I.M.E. 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 present invention is to design an apparatus for regulating the
tension of an electric current at will; this regulating not being effected by induction
as heretofore but by influence.
The construction of the apparatus is based on the following two facts:
1. By a rapid charging and discharging of a condenser a current is produced
having all the properties of a continuous current.
2. By discharging a condenser into another condenser of larger capacity the tension
of the current is diminished.
By a suitable combination of these two physical facts the object is attained in the
following manner :
In the accompanying drawings: fig. 1 represents a condenser in which an alternate
current of high tension can be changed into one of low tension.
This condenser consists of two smaller charging surfaces A B and two larger
discharging surfaces CD and the operation is as follows :-
The smaller surfaces connected with the generator will he charged by the first
electric wave in a certain sense and will be discharged by the next alternating wave
and charged in the opposite sense and so forth.

page_text: This alternate charging and discharging produces in the surfaces CD also alternating
charging.
Supposing to be the quantity of electricity which the primary surfaces the area
of which be F, can hold and their potential be V and supposing the area F' of the
secondary surfaces to be equal to F the quantity will also be Q and the potential V¹, it
will therefore be Q=V. F=Q=V₁, F' and.
F¹
The tension of the currents is therefore in inverse ratio to the surfaces, and the
larger the surfaces of CD the smaller will be the tension of the current, so that if
they are connected by a resistance S a current will circulate in the latter the electro-
magnetic force of which will be in a certain proportion smaller than that of the
generator.
These condensers are preferably constructed of tinfoil insulated by thin insulating
material such as paper, indiarubber leaves, mica or the like.
In cases where large surfaces are used, several such condensers may be arranged
parallel (see figure 2).
Instead of the large secondary plates, smaller ones may be used arranged parallel
and superposed (see fig. 3).
As in practice it is often preferable to use a continuous current instead of an
alternate one, the continuous current can be regulated by condensers in combination
with a current breaker (see figure 4).
This current breaker consists of a drum R. turning round an axis and is provided
on its circumference with two toothed and conducting strips M M¹ the teeth of which
are intercolating.
Four spring actuated contact makers ad and be press lightly against the strips, the
contact makers a and d touching each a tooth of one or the other of the strips while the
contact makers and e always touch the same strip. The contact makers a d are con-
nected with the generator while the contact makers be are connected with the charging
plates of the condenser. When the commutator revolves these plates will be charged
and discharged alternately producing the same effect as with an alternate current.
If the discharge current is also to be a continuous one, the condenser must be
charged alternately by the generator and discharged into the circuit.
When the condenser is connected with the generator the connection with the circuit
is broken and vice-versa. To regulate the tension the surface of the condenser is
increased during the discharging and this is preferably done in the following manner:
The condenser, fig. 5, is charged by a current of high tension and the plates thereof
are arranged or connected parallel, Fig. 6, before the discharge.
By this parallel arrangement the surface of the condenser is increased and therefore
the tension of the current decreased.
This connecting and reversing is effected by a commutator as represented in
figure 7. This commutator consists of cylinder C of insulating material. To this
cylinder are fixed alternately contact strips a, a', all all and rows of contact
studs b, 61, 61, 6 The contact studs connect the condensers M in series by the
spring actuated contact makers m, and with the generator by the spring actuated
contact makers A B. The strips a a' connect the condensers parallel and also with the
circuit by the spring actuated contact makers D E.
By reversing the connection the effect is also reversed and a low tension current
can be transformed into a current of high tension. Thus a current is produced
possessing all the properties of a continuous current.
If the second kind of condensers is used in combination with the first all problems
regarding changing and regulating currents can be solved i.e. :
A high tension alternate current can be transformed into a low tension alternate
current, or a high tension continuous into a low tension continuous or alternate, or a
low tension continuous into a high tension alternate and this into a low tension alternate
or a low tension continuous into a high tension continuous and this again into a low
tension continuous or alternate.

page_text: Having now particularly described and ascertained the nature of this invention, as
communicated to me by my foreign correspondent and in what manner the same is
to be performed, I declare that what I claim is
In apparatus for changing or regulating electric currents.
1. For the changing of high tension alternate current into low tension alternate
currents the employment of condensers in which the charging surface is smaller in a
fixed ratio than the discharging surface substantially as specified.
2. For the changing of a high tension continuous current into a low tension
alternate current the employment of condensers in which the charging surface is
smaller in a fixed ratio than the discharging surface in combination with a current
breaker connecting the charging surface of the condenser alternately with the
opposite poles of the generator substantially as specified.
3. For the changing of a high tension continuous current into low tension con-
tinuous current the employment of condensers in which the charging surface is
smaller in a fixed ratio than the discharging surfacein combination with a commutator
connecting the condensers in series for charging and in parallel are for discharging,
substantially as specified.
4. For double changing of the current the employment in combination of two
condensers as described, one of which increases the tension while the other decreases
it substantially as specified.
D
لبهيم
T
1605