Improvements in Regulating Appliances for Arc Lamps.
Year: 1895

page_text: Date of Application, 11th May, 1895
Complete Specification Left, 11th Feb., 1896-Accepted, 11th Apr, 1896
Improvements in Regulating Appliances for Arc Lamps.
ROOKES EVELYN BELL CROMPTON of Mansion House Buildings, London E.C.,
Electrical Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to regulating appliances for arc lamps and more particularly
to those appliances by means of which the energy required by the lamp can be
varied froin time to tiine according to lighting requirements.
For instance, in some cases it is very desirable that are lamps used for lighting
streets should give a light of 1000 candles from dusk up to 11 p.m and from 11 p.m.
to sunrise the light should be reduced to a smaller amount say 500 candles and that
this reduction of energy and hence of light should either be effected automatically.
or by hand switching or in some cases by electrical controlling apparatus worked
from a central point.
One manner of carrying out the above object is to provide the lamp with a
differential regulating arrangement consisting of a pair of electro magnetic devices
which may be either solenoids or elecu o magnets worked as is usual in differential
lamps e. one pair of magnets is wound with n large wire and is placed in series with
the main current and the other pair wound with fine wire is connected in shuut
across the arc.
a lamp is required to burn sometimes nt 5 amperes and sometimes at 10 amperes
I wind the series coil for 5 amperes so that the lamp works and regulates satisfactory
when 5 amperes is passing through it.
I also provide a by-pass to the above series coil of the proper resistance to pass
the extra 5 amperes required to make the total current 10 amperes at the time when
this current is required and this switching can be effected from a fixed number of
positions in the town by hand or in some cases I supply at each of these positions a
e-lay devised for actuating this switch from one central point.
In other cases I prefer to use within each lamp a separate and additional electro
magnetic device so contrived that it will itself close a by-pass across the main to
give the Iniger current and automatically open this by-pass if the current through
this electro magnetic device is very slightly reduced. It follows by the use of this
latter arrangement a considerable number of lamps arranged in series can be made
to vary the current through a very wide limit by a comparatively small alteration
in the electro motive force at the terminals of the whole series.
Another method by which this separate electro magnet may control the working
of the lamp and obtain the sanie result is by winding the series coils proper of the
lamp with a double winding and airanging the extia electro magnetic device cut
out this extra col or allow it to get into action according to comparatively small
changes in electio motive force at the terminals of the series of the lamps as before
described.
It is evident that this last method of winding may be worked in two ways,
either
the two coils may be switched in to assist one another or the second coil can be
wound so that when switched in it weakens the action of the first coil.
In some cases I can make the action of the electio magnet more prompt by
compound winding it, that is to say in addition to the main cent coils that
are wound on to it I wind a few turns of the shunt circuit proper of the lamp
tself.
'

page_text: In some cases I wind over cach main coil several layers of fine wire in order to
provide a sufficient number of turns that a very small current passing through the
whole would give the ampere turns equivalent to those of the ordinary main coils.
It is obvious that these can be switched in by any of the above mentioned devices
and the current inay be wasted.
Another method of carrying out the arrangement of obtaining the object of
varying the magnetic pull of the winding may be by means of either the re-lay
before mentioned or by the special electro magnetic device actuating a switch so as
to change the main winding of the series winding of the lamp above referred to
from several coils arranged in parallel to the same arranged in seues as-is well
known in switching apparatus for varying the field of electric motors used for
tiancars and similar purposes.
R. E. CROMPTON.
'Improvements in Regulating Appliances for Aro Lamps
I ROOKES EVELYN BELL CROMPTON of Mansion House Buildings, London, EC.
Electrical Engineci 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. :-
My invention relates to regulating appliances for arc lamps and more particularly
to those appliances by means of which the energy required by the lamp can be
varied from time to time according to lighting requirements.
For instance in some cases it is very desirablo that are lamps usel for lighting
streets should give a light of 1000 candles from dusk up till 11 p.m. and from
11 pm. to suprise the light should be reduced to a smaller amount say 500 candles and
that this reduction of energy and hence of light should either be effected automatically
or by hand switching or in some cases by electrical conti olling apparatus worked
from a cential point.
One manner of carrying out the above object is to provide the lamp with a
differential regulating arrangement consisting of a pair of electio magnetic devices
which may be either solenoids or electro magnets worked as is usual in differential
lamps, te, one pair of magnets is wound with a large wire and is placed in series
with the main current and the other pair wound with fine wine is connected to shunt
C across the arc
If a lamp is required to burn sometimes at 5 amperes and sometimes at 10 amperes
I wind the series coil for 5 amperes so that the lamp works and regulates satisfactory
when 5 amperes is passing through it.
I also provide a by-pass to the above series coil of the proper resistance to pass
tho extra 5 amperes requned to make the total current 10 amperes at the
time when this current is required and this switching can be effected from a fixed
number of positious in the town by hand or in some cases I supply at each of these
positions a re-lny devised for actuating this switch from one central point.
In other cases I prefer to use within each lamp a separate and additional electro
magnetic device so contrived that it will itself close a by-pass across the main to give
the larger current and automatically open this by-pass if the current through this
electro magnetic device is very slightly reduced. It follows by the use of this
latter arrangement a considerable number of lamps arranged in series can be made
to vary the current through a very wide limit by a comparatively small alteration
in the electro motive force at the terininals of the whole series.
Another method by which this separate electro magnet inny control the working
of the lamp and obtain the same result is by winding the series coils proper of the
lamp with a double winding and arranging the extra electro magnetic device cut

page_text: out this extra col or allow it to get into action according to comparatively small
changes in electro motive force at the terminals of the series of the lamps as before
described.
It is evident that this last method of winding may be worked in two ways; either
the two coils may be switched in to assist one another or the second coil can be
wound so that when switched in it weakens the action of the first coil
In some cases we can make the action of the electro moguet more prompt by
compound winding it; that is to say in addition to the main circuit coils that
are wound on to it I wind a few turns of the shunt circuit proper of the lamp
itself.
In some cases I wind over each main coil several layers of fine wue in order to
provide a sufficient number of turns that a very small current passing through the
whole would give the ampere turns equivalent to those of the ordinary main coils.
It is obvious that these can be switched by any of the above mentioned devices and
the current may be wasted.
Another method of carrying out the arrangement of obtaining the object of
vanying the magnetic pull of the winding may be by means of either the relay
before mentioned or by the special electro magnetic device actuating a switch so as
to change the main winding of the series winding of the lamp above referred to from
several coils arranged in parallel to the same arranged in series as is well known in
switching apparatus for varying the field of the electric motors used for tram cara
and similar purposes.
DESCRIPTION OF THE DRAWING,
The figure shows diagrammatically one form of the arrangement applied to two
lamps in series, but it is equally applicable to any number of lamps in series.
A B C D is the usual regulating resistance. E E the series windings of the lamps
and G G the arcs. We will suppose the lamps, as shown, to be working at
5 amperes, and proceed to describe the means for making them burn at 10 amperes
by closing the switch II.
On A Da point C must be selected such that the resistance of the
Circuit CEEF is equal to the resistance from C to F through the switch H
and the wire H F.
Another point 13 must also be selected such that the resistance A B plus CD
is of a suitable value for working the lamps at 10 amperes.
Then on closing the switch H 5 amperes will, as before, pass through E E
and an additional 5 amperes will be shunted across E E and supplied to
the arcs.
The shunt windings of the lamps are not shown in the diagram, but are as usual
coupled across the aics.
Having now particularly described and ascertained the nature of my said inven-
Lion and in what manner the same is to be performed I declare that what I
claim 18-
1. The use in regulating arc lamps of a switching device by means of which the
current passing through the arcs may be varied without affecting the difference of
potential across the arc, substantially as herein described and set forth.
2. In electric are lamps the use of a regulating appliance so contrived that the
current passing through the arc may be increased to any desired value without
affecting the satisfactory working of the regulating mechanism of the lamps.
Dated the 11th day of February 180
DDA ORDE U
55 & 56 Chancery Lane, London, Agents for the Applicant.