Improvements in Automatic Potential Regulators for Dynamos.
Year: 1899

page_text: Date of Application, 27th Feb., 1899-Accepted, 2nd June, 1899
Communicated from abroad by THE TIRRILL AUTOMATIC POTENTIAL REGULATOR
COMPANY, a Corporation organized under the Laws of the State of New
Hampshire, one of the United States of America, and doing business in
the City of Laconia, in the County of Belknap, in said State.
Improvements in Automatic Potential Regulators for Dynamos.
I, NEWNHAM BROWNE, of 73, Cheapside, in the City of London, Fellow of the
Chartered Institute of Patent Agents, do hereby declare the nature of this in-
vention, which has been communicated to me by The Tirrill Automatic Potential
Regulator Company, a Corporation organized under the Laws of the State of
New Hampshire, one of the United States of America, and doing business in the
City of Laconia, in the County of Belknap, in said State, and in what manner
the same is to be performed to be particularly described and ascertained in and
by the following statement:-
The present invention relates to, and consists in, certain improvements in
automatic potential regulators for dynamos.
Heretofore, it has been proposed to automatically regulate the potential or
voltage on the supply wires leading from the dynamo, so that an even potential
shall always be maintained on said wires, notwithstanding the varying tax or
demand made upon the supply wires by the starting and stopping of electric
motors, or by cutting in and out of electric lights, or by rendering active and
idle other users of electricity. In such prior regulators a rheostat (or other
resistance) has been employed, in connection with the dynamo, of such resistance
as to at least compensate for the ordinary maximum variations in the load,
(that is to, say, if there is to be anticipated the simultaneous cutting in and out of
one-hundred incandescent electric lamps, then this rheostat should have a
resistance, at least approximately equal to that of the one-hundred electric
lamps) and a solenoid, or solenoids, have been located in a shunt of the supply
circuit and so arranged relatively to the resistance that when they act, they
operate to cut in or out the entire regulating resistance, instead of gradually
cutting it in and out as is more customarily done.
As an example of the type of regulator which at once cuts in and out the entire
regulating resistance, reference is made to British Patent No. 1535, dated
January 28. 1889, to Illius Augustus Timmis.
The present improvements relate to potential regulators of this type. In
such prior regulators there are certain objections owing to the tendency of the
contact points (controlled by the solenoids) to stick and accident to the wires
of the solenoid circuit permanently cuts out the resistance, thus permitting the
potential to rise to a dangerous point. The object of the present invention is to
overcome these defects, and also to improve the structural details so as to ensure
proper operation in practice.
The present improvements are illustrated in the accompanying drawings.
wherein,
Figure 1 is a front elevation of the instrument; Figure 2 a vertical longi-

page_text: tudinal section on line 2-2 of Figure 1; Figure 3 a diagram of circuits;
Figure 4 an enlarged detail in perspective of the solenoid contacts.
In the drawings, A A are the hollow coils of two solenoids arranged in vertical
position and fixed within a suitable case on a non-conducting backing, preferably
of marble or slate. In the center of these hollow coils there vibrate freely in
vertical direction the soft iron cores B B, made preferably of laminated wire
and suitably encased with rubber shells. The tops of these cores are respectively
connected by stems to, and suspended from, the outer ends of delicately balanced
levers CD, of metal which are respectively fulcrumed upon pivots within sup-
porting frames or brackets a a, and at their inner ends are lapped to form a
loose jointed connection, and are pulled down by a spring E, having a stem b,
and tension-adjusting devices at its lower end. To hold the cores B B against
swinging about and dragging frictionally against the inside of the coils a stem c
extends from the lower end of each core, and is guided in an arm & so that each
core is always maintained in an exactly concentric position with reference to its
coils without touching the inside of the coil at all.
The lever C, has fixed to its inner end a metal boss e, carrying a platinum
contact face, or point f (see Fig. 4). The other lever D), where it laps over
lever C, is provided with a metal disk or roller g, arranged in a vertical plane
and bearing upon the end of lever C so as to roll in contact therewith when the
inner ends of the levers rise and fall, thereby reducing friction at the point of
articulation.
Just above the end of lever D, (see Fig. 2), there is arranged a flat spring h,
adjusted downwardly by a set screw i, mounted in a stud j, projecting from the
back of the instrument. This spring serves to quickly throw down the inner
ends of the levers when they rise and strike against the same, and its tension
may be adjusted-to-act-sooner or later as circumstances may render desirable.
Just below the platinum contact point f, there is a second contact point,
mounted upon a flat horizontal spring F, adjustable longitudinally by screws 1,
in a bracket-shaped slide G, whose horizontal member is slotted and clamped
to a bracket-1 (projecting from the back) by means of a nut m, and screw n.
1, and 4, are binding posts that connect with the two upper wires of the
circuit to be regulated. 2, and 3, are binding posts connecting with the wires
of the shunt circuit that energizes the field magnets of the dynamo. These
binding posts 2, and 3, are connected to contact points s, and t, (see Fig. 3)
controlled by a relay magnet I, placed in an independent or supplemental circuit
taken from the supply wires through binding posts 5, and 6. The heavy black
lines in Fig. 3, show this supplemental circuit which constitutes one of the
principal features of this improvement. The light continuous line from binding
posts 1 to 4, shows the main circuit which is here termed the "primary branch
circuit," and the dotted line shows the dynamo shunt circuit.
Referring now to Fig. 1, these circuits will be traced through the instrument,
and detailed description of the same will be completed.
For the primary branch circuit the current from one of the supply wires 7,
entering binding post 1, passes by wire S to an electro magnet J, (whose function
will be hereafter described) and through the same to wire 9, solenoid coil A,
wire 10, solenoid coil A on the other side, then by wire 11 to resistance K, and
thence by wire 12 to binding post 4, and the other supply wire 13. The re-
sistance K, interposed in this circuit is simply for the purpose of preventing the
burning out of the coils A A, and J, from too great electrical energy. This
resistance consists of a series of non-conducting slabs, each with a single layer
of silk covered German silver wire, the spacing of these coils on separate cores
being for the purpose of allowing a thorough ventilation and preventing the
heating of the coil, as shown in Fig. 2.
The supplemental circuit, which constitutes one of the features of improvement
is introduced (see Fig. 1 and 3) through the binding posts 5, and 6. This is
taken off the supply wires 7, and 13, as follows. Coming in from supply

page_text: wire 7 to post 5, to wire 14, it goes to a metal contact 15, which is an insulated
stop of the armature L of magnet J. From this stop contact it passes through
the normally closed armature L which is constantly attracted by the constantly
energized condition of magnet J. From armature L, it passes to wire 10, and
solenoid lever C, and, whenever contacts f, and are closed, it passes through
them to wire 17, the coils of relay I, to wire 18, and the binding post 6 to the
supply wire 13, of opposite polarity. The relay magnet I has an armature M
with a platinum points playing upon the platinum point t. The point s is
connected by wire 19 with binding post 3, and wire 20 with one pole of the
dynamo field magnet, and the other point t, is connected by wire 21 to binding
post 2, and wire 22 with the other pole of the dynamo. The contact points s
and t, it will be seen constitute the terminals of the shunt circuit of the dynamo
field magnets, in which shunt circuit is arranged the resistance N, and, in the
action of the present invention, when the current on the supply wires falls in
potential, this shunt circuit is closed through the contacts s, t, and the re-
sistance N, being thereby cut out, there is a greater energizing of the field
magnets, and the dynamo is made to instantly bring up the potential of the line
in an automatic manner to compensate for its reduction due to the throwing in
of lights, motors, or other users of the current. In previous regulators the
terminals of this shunt circuit have been closed by the direct action of the
solenoid levers C, D, at f, k. This, however, has been found to be objection-
able, for the reason that the great amount of energy (that these points f, k,
were obliged to carry for the regulation of large dynamos) together with the
induction, causes a spark at the points, and after the spark is broken by the
condenser, said points come together and stick hard enough to require from one
to three volts above the normal voltage to open them again, thus destroying
the sensitiveness of the regulation, and causing a flickering of the lights ou
the line.
The present invention is designed to relieve the sensitive contact points from
this great amount of energy, and this is accomplished by the supplemental
circuit through the binding posts 5, and 6, and the relay I, the shunt circuit of
the dynamo being controlled through terminals worked by the relay, and the
relay being controlled by the supplemental circuit worked by the solenoid contact
points f, and k.
Referring now to Fig. 3, particularly, (and remembering that magnet J is
always energized, and the armature L rests normally upon stop 15) whenever
the potential on the line 7, 13, falls, the inner ends of levers C, D), descend,
and contacts f and come together. This completes the supplemental circuit
through relay magnet I, which being energized, closes the contact terminals s, t,
of the shunt circuit of the dynamo field magnets, thus entirely cutting out the
regulating resistance N, and at once increasing the potential on the line corre-
spondingly to the tax made upon it. When equilibrium is restored, and the
potential is brought up to normal, the solenoid coils A A, lift the inner ends of
levers CD, against the spring E, thus breaking contact at f, and k, and also
instantly breaking contact at s, t, thereby again at once throwing in the full
resistance N, into the shunt circuit. Thus a sensitive automatic regulation is
obtained at all times and under all conditions.
The function of the electro magnet J will now be described. It will be seen
that if the solenoid circuit from 1 to 4 be broken at any time by any accident,
as the falling of a tree, or any similar cause, then the spring E would hold the
contacts f and into permanent closure, rheostat N would be permanently cut
out, and hence the potential on the line would run up to a high and dangerous
pitch. To prevent this the supplementary circuit from 5 to 6, is made to be
automatically broken by any accidental breakage of the main solenoid circuit,
through the instrumentality of the electro magnet J, its armature L, and con-
tact point 15; for, if the main circuit which passes through coils of magnet J,
be thus broken, said magnet is demagnetized, its armature L, flies up and contact

page_text: is broken between it and point 15; and, as these are also terminals of the
supplementary circuit, it will be seen that the supplementary circuit is broken,
contacts f, and k are rendered null in effect, and even if they be closed no current
flows through the supplementary circuits, and the terminals s, t, of the shunt
from the dynamo are kept permanently open, and the line then works with the
constant resistance of the rheostat N.
When more than one dynamo is employed on the supply wires, it is obvious
that the relays I, and the shunt circuits of the dynamos may be multiplied to
correspond with the number of dynamos used.
In some applications of the invention it may be desirable to reduce the energy
of the solenoid coils A. A, and for this purpose, the same may be compounded
by winding coils of wire 0, 0, upon the saine in opposite direction to the sole-
noid coils. These additional coils 0, have a series of binding screws P, arranged
at different points along their length, and connections Q, R, S, are arranged
to throw the current through any portion of these added coils to choke or retard
the working current in the solenoid coils to any desired degree.
In illustrating the invention, two solenoid coils A A and two levers C, D,
are shown, but it is obvious that the object of the invention might be secured
with only one such coil and lever, and the invention is designed to have this
scope. The use of two coils and two levers is preferred for the reason that it
makes more efficient and more symmetrical apparatus.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what I
claim is:
1. In a potential regulator for a dynamo, the combination with the main supply
wires, and a
a normally closed primary branch circuit connected to the supply
wires and provided with one or more operating helices; of a pair of contact
terminals arranged to be opened or closed upon each other by the action of said
helices, a supplementary branch circuit connected also to the supply wires and
terminating in the pair of contacts aforementioned, a relay arranged in this supple-
mentary circuit, a shunt circuit connecting with the dynamo and provided with
a rheostat, said shunt circuit having two terminals extended to the armature of
the relay and being opened or closed by the same, substantially as and for the
purpose described.
2. In a potential regulator for a dynamo, the combination with the main
supply wires of a solenoid regulator circuit connected to the supply, a shunt
circuit from the dynamo field magnets with rheostat, a supplementary circuit
and relay, the relay being worked by this supplementary circuit and controlling
the terminals of the shunt circuit and the supplementary circuit having ter-
minals operated by the solenoid circuit, and also an electro magnet placed in the
solenoid circuit and having an armature arranged when attracted to close the
supplementary circuit and to open the same and render it inoperative whenever
the solenoid circuit is accidentally broken, substantially as and for the purpose
described.
3. In a potential regulator for dynamos the combination of the solenoid coils,
their cores, and the lever C, D, bearing contact point as described, a spring
for drawing the inner ends down, and a superposed adjustable spring arranged
above the inner ends of the levers to be impacted against by. the rise of the
inner ends of the levers whereby the latter are made to quickly return, substan-
tially as described.
4. In a potential regulator for dynamos, the combination with the solenoid
coils, their cores, and the levers C, D, having contact points as described, the
inner ends of said levers being lapped and the upper one having a spring to draw
it down and a rotary disk or roller resting upon the lower lever, said disk being
arranged in the plane of the levers to form a sensitive articulation, substantially
as described.

page_text: 5. In a potential regulator for dynamos the combination with the solenoid
coils, their cores, and the levers C, I), having contact point as described, a sub-
jacent spring bearing a contact point, and a clamping support for said spring
made adjustable to grasp said spring at different positions along its length to
vary its range of vibration, substantially as and for the purpose described.
6. The improved automatic potential regulator for dynamos substantially as
herein before described with reference to the accompanying drawings.
7. The improved automatic potential regulator for dynamos substantially as
described.
Total 11. 0121 1
e T 1
1000