and in Apparatus therefor.
Year: 1887

page_text: Date of Application, 10th Dec., 1887
Complete Specification Left, 10th Sept., 1888
Complete Specification Accepted, 12th Oct., 1888
P
and in Apparatus therefor.
I, WILHELM LAHMEYER in care of Messieurs E. Bede & Cie. of 37, Rue
Philippe-le-bon Brussels in the Kingdom of Belgium Electrical Engineer do hereby
declare the nature of this invention to be as follows:-
This invention consists in an improved method and means for maintaining a constant
electro motive force in distant portions of a circuit when the resistance in such portions
is varied as for instance in a lamp circuit, by the exclusion or insertion of lamps;
also in the application of this method to the regulating of the electro motive force of
shunt or compound dynamos.
The method consists essentially in causing a solenoid formed by several spirals of the
main current lead, to act upon a movable armature, so that the movement thereof
depends upon the intensity of the main current, said movement causing resistances to be
interposed or excluded from the line, that is to say, the resistance thereof to be
increased or diminished in inverse proportion to the variation of the intensity, so that
the loss of electromotive force which is equal to the products of these factors shall
remain constant.
For this purpose, the apparatus may consist of a bobbin or coil consisting in or
formed by several windings or spirals of the main current wire, wound upon a part of
a shield of insulating material, the same being hollow and hermetically closed. The
shield is partly filled with mercury, which is placed in electric communication with
one end of the aforesaid bobbin and in said mercury floats an armature or solenoid
core. At intervals on the wall of the shield are arranged contacts leading respectively
to resistances in multiple are interposed in or forming part with the main line, or to the
divisions of a Rheostat regulator of the usual construction interposed in the circuit.
The rise of intensity of the current in the bobbin causes the armature to descend in
the mercury, so as to cause the latter to rise by the displacement and thus interpose
further shunts and diminish the resistance. Consequently also with a fall of intensity the
armature rises, the mercury sinks, certain of the shunts are excluded and the resistance
is increased.

page_text: This apparatus may be modified in that in place of causing the armature to be raised
by the hydrostatic pressure of the mercury the force exercised by a counterweight or
spring may be utilized for this purpose, the contacts being established by friction
brushes or by immersion of electrodes in cups containing mercury.
The arrangement of the resistances to be interposed or excluded direct, by the
contacts placed at different heights, may be varied by causing such contacts to complete
circuits whereby electro magnets are operated to act upon their armatures and thus
interpose or exclude the said resistances in the main line.
The said apparatus may be likewise so arranged in combination with the main lines
of a machine in shunt or compound, as to regulate the electromotive force in the
neighbourhood of the dynamo.
To prevent the intensity of the current from becoming too feeble, when for instance
there are only a few lamps in circuit, an apparatus such as above described may be
interposed at the place where the tension is to be maintained constant, so as to interpose
between the principal conductors a resistance equivalent to a certain number of
lamps.
TAL
1
1007
HERBERT & Co.,
Agents to Applicant.

page_text: Improvements in or relating to the Regulation of Electric Currents
and in Apparatus therefor.
1, WILHELM LAHMEYER, in care of Messieurs E. Bede & Cie. of 37 Rue Philippe-
le-Bon, Brussels, in the Kingdom of Belgium, 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 :-
:-
The object of this invention is to overcome certain drawbacks in the distribution of
electricity from a central station to groups of lamps connected in multiple arc, namely
the loss of E.M.F which occurs and the fluctuation of the same in the outlying
portions of a long circuit varying with the number of lamps in use.
Heretofore, to regulate from the central station the EMF of outlying parts of the
circuits, a special double wire connected in multiple arc, is led from said outlying
paris to the central station to operate there a voltameter or a relay. Where a volta
meter is employed a continual watch has to be kept on the indications of this apparatus
so that resistances may be inserted or excluded in the main circuit by the operator in
charge, where a relay is used however the latter automatically fulfils this function by
acting upon an automatic tension regulator.
This method is seldom used since the installation along the whole length of the line
of a double wire simply for control is inconvenient and expensive, the method is
complicated and by reason of the feebleness of the current drawn off for the control of
the latter is not sufficiently exact.
By installing the automatic controlling apparatus in proximity to the parts to be
regulated, the cost of the double wires would be avoided, but such method would have
the inconvenience of dispersing the instruments instead of preferably keeping them all
in the central station under immediate supervision.
This invention consists in a regulator which may be placed in the central station or
elsewhere, will control the tension in any distant part of the circuit without a special
controlling circuit and act automatically with great simplicity and perfect security.
It is based upon the principle of making the resistance in the outlying parts of the
principal circuit depend upon a bobbin formed by several windings of the said
principal circuit.
Fig. 1 is a diagram representing a central station and outlying groups of lamps etc.
operated from the station. A and B are the main leads in the station receiving from
the dynamo or source of electricity a current of constant EM F.
Those lamps etc. in the group N in close proximity to the station are connected
simply to main leads without interpolation of any special apparatus, the wires being
calculated for small loss of tension. In connecting also the distant stations F F F
there will be a considerable loss of EMF owing to the length of the conductors a¹¹,
ab, a3 13. Under these conditions each of the apparatus R¹ R³ R³ inserted in

page_text: number of zones of uniform tension.
Let be the tension or E M F at the central station
20¹ the resitsance of the circuit a¹¹
the EMF at F¹
and the intensity of the current in the circuit a¹ which depends on the
number of lamps in use.
Then I¹¹ = x - vor the value of the loss of E M F.
Supposing 10 volts loss of E M F (to have the conductors sufficiently small) to be
adopted when the apparatus R¹ is not in action. Then the said apparatus is intended
to increase or diminish the resistance w' in accordance with decrease or increase of the
intensity I so that the loss of E MF (¹) remains constant, in this case equal to
10 volts.
The remaining figures of the drawings show various methods of performing this.
Fig. 2 shows an instrument which is inserted in the main circuit, by means of the
terminals I and II. The current traverses first the bobbin S formed by a few coils
and passes thence into the mercury enclosed in a tube of glass, vulcanite or any other
non-porous insulating material around which the aforesaid bobbin S is wound. The
ends of wires of iron, nickel or other metal not attacked by mercury, are passed at
different heights through the wall of the tube, being hermetically fastened in the
thickness of the wall so that air cannot enter the tube. These wires are in communica-
tion with the resistance coils and thence with the terminal II. An iron armature
floats freely in the tube, its movement being guided by the star shaped plate pp.
On each end of the armature is a small block of rubber gg. The free space in the
tube is filled with nitrogen or other inert gas. It will be understood that instead of
passing through the side walls the wires may all enter the tube at the top and pass
down the wall of the tube and terminate at different levels therein.
The more the intensity of the current traversing the bobbin increases, the more the
float is immersed in the mercury, the latter stands at different levels according to the
position of the float therein, so that a greater or less number of wires are immersed
until, with the maximum intensity, all the wires are in contact with the mercury.
The different resistances are so calculated that the equation before mentioned may
be satisfied for the different values that I may take. This may be done by a very
simple calculation, the apparatus is erected, and the different levels to which the
mercury rises for the different values of I are found by experiment.
The resistances to be interposed are also easily calculated. To prevent the inser-
tion of this apparatus from increasing the tension too much, it may be so disposed
that the resistances, or at least the higher resistances as 10090 80 etc. may be
an integral part of the line and to this end it is only necessary to lay between the
apparatus and a point of the line situated at a certain distance, a certain number of
parallel wires of suitable diameter insulated from one another. The diameter of the
wires is rather larger than that necessary for the exact resistance required, the latter
being completed by coils of wire of higher resistance and adjusted simply according
to the length of the wire. It is not of advantage to insert the higher resistance in
the line but to form them of resistance coils united in a corner lead connected to the
line at a somewhat distant point. Fig. 3 shows this method. In practice it is best
to connect the resistances 100 907 80 etc. in parallel on a wire common to all,
so that their installation is as simple as that of a single wire. In place of increasing
the resistance by excluding parallel conductors from the circuit as in Fig. 2 & 3,
there may be but one conductor including convenient resistances grouped in series as
in Fig. 4. The bobbin S is here arranged exactly as in Fig. 2 or 3 and it will be
seen that the resistances W1 W2 W3 are successively inserted according to the level
of the mercury. The advantage of this method is that the exterior circuit is undivided

page_text: while the apparatus does not increase the tension when the intensity is at its
maximum.
With feeble currents the wire may be melted into a tube glass but for strong
currents, the tubes are best made of vulcanised fibre with terminals screwed into the
wall as in Fig. 4, the terminal screws should be of iron or other metal inattackable
by mercury, leather washers or collars may be placed under each for greater
security. When there are many terminals they may be arranged on a special line up
the tube. There may be a glass window in the tube if desired to enable the height of
the mercury
to be seen,
but this is not necessary. The method described will only
allow a minimum tension at the poles of rupture so that the formation of an arc is not
possible, the spark produced on rupture of contact will produce no oxydation or
chemical action since the tube is filled with an inert gas. The mercury is therefore
neither consumed nor soiled.
In Figs. 5 and 6 the apparatus before described in place of directly inserted or
excluding the resistances required, operates to furnish current to certain electro
magnets, which acting as relays attract their armatures and establish contacts neces-
sary for the insertion of the resistances.
The electro magnets e have coils of high resistance one extremity of which is con-
nected to a platinum wire fused into the glass tube. The mercury is connected by
the wire c to one of the main lead (+) the other extremities of the electro magnets
are in connection with the other main lead (-).
By the insertion of the different contacts 1, 2, 3, etc. in the mercury the various
electro-magnets are operated by a feeble current (about of an ampère) attract
their armature levers etc. and cause them to dip into. the trough T. When the
current ceases to pass the armature levers are raised by the counterpoises g, or springs
taking the place of the latter.
The main current traverses the bobbin S¹ of the principal relay and passes thence
to the iron trough T containing mercury, when the levers are immersed in this
trough the current passes direct by these levers and the sockets n to, the exterior line F.
If the first lever is raised the resistance W₁ is interposed and so on.
When
these apparatus are employed in indirect action the intensity of the current in the
exterior circuit may be as great as desired. It suffices to give the contact levers h
sufficient dimensions. It will be noticed that the only part where sparks may be
produced by rupture of current is in the trough T. The difference of tension resulting
from the disconnecting of the levers being extremely small the consumption of mercury
is insignificant.
By the employment of the strong main current as a regulating force the differences
of level of the mercury will be considerable and the contacts may be placed at
comparatively large distances apart, the connection and disconnection will then be
made with great precision.
I do not confine myself only to the employment of the hydrostatic pressure of
displaced mercury as an antagonistic force to the attraction of the bobbin S, but may
use any other mechanical force as for instance the tension of a spring or gravity of a
weight Thus Fig. 7 shows a device on the principle of a spring and more particularly
arranged for use with the contact lever arrangement of Fig. 6.-There the core of the
bobbin S is freely suspended on a spiral spring and is in connection with a pivoted
lever having depending from its free end a series of contact wires terminating
successively at different levels, the passage of the current causes the core to be drawn
down more or less and the contact wires to be successively immersed in the mercury
in the trough N. This mercury is in connection with the main lead (+) and the
wire 1. 2. 3. 4 with the respective electromagnets of Fig. 6.
In using this device in place of that in Fig. 2 to 4 the current is led direct from
the bobbin S to the trough N and the wires 1. 2. 3. 4 etc. should be larger diameters
according to the intensity and should lead direct from the trough to the resistances.
These electrodes may also be formed of thin plates arranged within each other as
concentric tubes, their opposite extremities are fimmersed in seperate mercury cups as
with the lever h in Fig. 5.

page_text: The apparatus before described may be used to control the current delivered direct
by a dynamo whether in shunt or compound, that is to say to keep the tension thereof
constant by combining with the apparatus in Fig. 2 resistances in such a manner that
as the principal current strengthens the resistance diminishes to the desired amount to
maintain the tension to the corresponding amount; In this case resistances in parallel
may he employed as in Fig. 2 or in series as in Fig. 4.-Since in this case there is
only question of feeble currents the resistances may be combined direct with the use
of electromagnets as in Fig. G.
By this method of varying the resistances according to the variations of intensity,
the E M. F may be kept constant, or may be increased or diminished.
An advantage of the improved method over similar relays operated by change
of E.M.F, is that the latter does not operate until the E.M.F has been altered,
whereas the present method prevents change of E.M.F.
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 :
For regulation of the E.M.F in electric circuits:
1) The combination with the circuit of a solenoid inserted therein and a moveable
armature thereto controlled by the intensity of the current and a compensating static
force, so that the movements of the core cause resistances to be included or excluded
according to the intensity whereby the E.M.F. is regulated to remain constant or in
any other manner desired.
2) The combination with the circuit of a solenoid inserted therein a tube with movable
armature floating in mercury in said tube so that said armature is immersed to a depth
corresponding to the intensity of the current contacts arranged at different levels in
said tube adapted to come in connection with the mercury on the rising thereof and
resistances in series or parallel in connection with the said contacts, said mercury
being included in the circuit and causing the insertion or exclusion of resistances
in the circuit according to its level in the tube substantially as set forth.
3) The combination with the circuit of a solenoid inserted therein, a moveable
armature thereto supported by a spring or other suitable compensating force, a pivoted
lever connected to said armature, a series of consecutively acting contacts thereon, a
mercury trough or equivalent stationary contact therefor and resistances substantially
as & for the purpose set forth.
4) The combination with a solenoid and armature thereto effecting certain successive
contacts corresponding to the intensity of the current in the circuit of the solenoid of
a series of electromagnets in connection with said contacts for the insertion or
exclusion of resistances in said circuit for the purpose set forth.
5) The combination of the regulator herein before described with a shunt or
compound dynamo electric machine for the regulating of the E.M.F of the current
thereof.
6) In lamp circuits to prevent the strength of the current from falling too low the
combination with the apparatus herein before described of a resistance corresponding.
to several lamps and adapted to be inserted between the main leads upon attainment
of a certain minimum strength of current substantially as set forth with reference to
Fig. 8 of the drawings.