Improvements in Automatic Current Regulators.
Year: 1896

page_text: Date of Application, 4th Feb., 1896-Accepted, 7th Mar., 1896
[Communicated from abroad by STANLEY CHARLES CUTHBERT CURRIE, of the
City, County, and State of New York, United States of America, Electrical
Engineer.]
Improvements in Automatic Current Regulators.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent
Agents, 45 Southampton Buildings, in the County of Middlesex, 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 afford a simple and reliable method, whereby
the flow of electric current in a circuit may be regulated, and not permitted to
exceed a certain quantity. For example, in the case of electric storage batteries
supplying current, if the discharge of current exceeds a certain specified amount,
the storage batteries may be seriously injured.
The said invention comprises a method and apparatus for the automatic
protection of secondary batteries during their charge and discharge, so as to
prevent their injury by a too rapid condition of change.
By means of the said invention I am enabled to prevent vibration or jumping
of the control magnets under certain conditions when the currents are approaching
equilibrium.
Now, by my method, when the flow of current exceeds a given determined
amount, resistance will be automatically thrown into the main circuit, the amount
of said resistance being proportionate to the requirements.
For example, suppose a circuit with normal E.M.F. 100 volts and maximum
allowable current 100 amperes, thus making minimum allowable resistance of main
circuit one ohm; now, if by accident, or otherwise, the resistance shall fall below
one ohm, the automatic regulator will cause to be thrown into the circuit a
resistance equivalent to such decrease in the main circuit, and thus maintain the
total resistance at or near one ohm, and thereby prevent the current exceeding,
except by a comparatively small amount, the permissible current of 100 amperes.
This resistance is, in the apparatus shown, automatically and gradually inserted
into the circuit, without any sudden steps in the increase.
My process is likewise applicable to preventing the excessive rate of charging of
such storage battery, which is sometimes as disadvantageous as a too great rate of
discharge.
My invention will be readily understood from the accompanying drawings, in
which
Figure 1, represents diagrammatically an arrangement of my invention; and
Figure 2, substantially the same arrangement, showing, however, a different
form of the apparatus for inserting the gradually variable resistance, and showing
the switch in the battery charging position.
Figure 3, represents a view of an automatically varied rheostat substituted in
place of the liquid resistance, Figures 1 and -2.
Figure 4 is a diagrammatic representation of a modified form of the invention.
In my drawings, A represents the generator connected by wire p to the
conductor d; which connects to the translating devices T of the working circuit.
ID QI

page_text: operation, it is,, therefore, connected
The secondary battery B is connected
This selenoid C has the lever
arranged to operate two contacts F G
The other pole of the generator connects by wire a with wire having contact 6 of
the switch S. When the dynamo is in
directly to the wires c d of the main line.
with the wire d and wire e to solenoid C.
adjustable counter-balance weight s, and is
in mercury troughs D E.
and
The current being led to the solenoid C by the wire e, passes to the lever r,
which, in the position shown in Figure 1, contacts on its left-hand end with mercury
trough D connected with conductor h, which connects with the switch S and with
contact point of switch k and with wire connected to plate O, presently to be
described.
The other mercury trough E connects by wire g to expansion rod J, made of a
suitable material, for instance iron, to expand under the influence of the heat of
the electric current generated in said rod by its resistance.
In case the current passing through the solenoid C is in excess of that to which
the apparatus is adjusted by the position of the counter-weight s, the current then
passes by trough E and wire g to conducting rod J.
One end of this conducting rod J is attached to the frame H, preferably of
the same material as the rod J. The free end thereof is attached on pivot N
to a portion of a lazy-tongs. One arm of this lazy-tongs is fixed to the bar K
by bolts M, which bar K is attached to the reservoir R.
It will be readily seen that the extension of the rod J will rapidly separate the
pivots of the lazy-tongs Z, thereby increasing the distance between the plate O,
which is practically fixed in this apparatus, and the plates P P suspended on the
external pivots of the lazy-tongs, and which plates are connected by wires m m to
circuit c.
In the device shown in Figure 2, the same general structure is found, excepting
that the rod J is attached to the suspension lever V in such a way as to multiply
the motion of the rod J on the pivot W to which the plate O, as before,
suspended.
The plates (PP may be of any suitable material, such as copper, and the
liquid any suitable liquid, such as sulphate of copper, and I may use a variable
rheostat instead of the liquid reservoir for varying the resistance under some
circumstances, but I prefer the liquid resistance, as being more reliable, and more
easily actuated.
In the device shown in Figure 3, a variable resistance 11 is substituted
for the variable liquid resistance, the operation being otherwise practically the
same; the expansion of the rod J affecting the lever V and moving it over the
successive contacts thereby increasing the amount of resistance in the resistance
box, which connects as before with the wires 1 m.
The operation of my device will now be readily understood. The switch t of
the wire a being opened in the apparatus shown in Figure 1, the battery B is then
serving the line. The main circuit passes through C, and provided the current
does not exceed the permissible amount, it will pass through contact cup D, wire h,
switch S, switch-point k, wire l and plate O to plates P by wires m to wire c to
translating devices T, to wire d to battery B.
If, however, the current should exceed the permissible amount, it will, on small
excess of said amount actuate the solenoid C, and thereby make contact between
G and E, and break the contact between F and D. The contact between G and E
is made before the contact between F and D is broken, thereby preventing
sparking. Passing then by wire g and rod J, the excess of current heats the rod J
and expands the same, thereby separating the plate O from the plates PP, and
throwing in an increased resistance in the reservoir R.
It will be obvious that the resistance in the reservoir R is dependent upon the
distance between the plates, and that this distance is dependent upon the current
heating the rod J. Now, as soon as the rod J has expanded to such a degree that
the liquid resistance, together with the resistance of the rod, is equal to the

page_text: decrease of the resistance in the main circuit which has set the apparatus in
operation and has decreased to such an extent that the action of the solenoid C.
is reduced to its normal condition, the contact between E and G will be broken,
and the current will again flow through F and D, through wire 1, plate O,
plates PP, to main line c. In this case, as the rod J cools, the liquid resistance
in R will gradually lessen, and if the resistance in the main circuit has not been
increased in the meantime, the current through the solenoid C will gradually
increase until the lever is again actuated and the rod J reheated so as to bring
up the liquid resistance again to the required amount.
The operation of the device shown in Figure 2, is substantially the same. The
lever V being swung to the left, separating the plates, upon the expansion of the
rod J. In this case strict parallelism of the plates O and P can be obtained,
which is, in some respects, an advantage. In this figure the dynamo is in
operation, and its current passes partly to the line e d, and partly passes by the
wire h through lever r to the battery B. In case of an excess in the charging
current, as before, the solenoid C is operated, breaking the direct contact
through F D, and forcing the current to travel through the resistance between
plates O and P, which is increased corresponding to the heating of the rod J.
In the device shown in Figure 4, B represents the secondary battery, and A the
dynamo for charging the same, C¹, represents a control magnet, and D a cut
out magnet affecting a circuit from the control magnet C. J represents the rod
expansible by heat, operating a lever V having suspended to it plate O in the
solution in tank or reservoir R.
Under certain conditions the current flows from the movable plate O to the
fixed plate P through the solution. 9 represents an alarm bell, operative under
certain conditions. The magnets C¹ and D' are solenoids operating levers K, L,
each making double mercurial connections, as plainly shown; these connections
being so adjusted that one is made before the other is broken. M is a switch for
cutting out the dynamo.
During conditions of discharge of the battery B the operation is as follows:
The current passes through wire l, solenoid C', wire 2, cups 3, 3, wire 4, cups 5, 5,
wire 6, wire 7, translating devices or lamps N, wire 8, to battery. In case, however,
the current flowing from the battery exceeds the permissible amount, the solenoid Ci
operates the lever K, thereby making contact by wire 9, through cups 10, 10, and
wire 11 to expanding rod J thence by lever V to plate O to plate P to wire 7,
and so to the battery. The action of the excess of current on the rod J is to
expand the same, as above described, thereby increasing the resistance between
plate O and plate P by moving the lever V to the left. As the lever V moves to
the left, it leaves the bell-crank lever P¹ pivoted at O₁ and thereby allows .the
circuit to be completed through a shunt circuit comprising wire 12, cups 13, 13,
wire 14 to magnet D', which is of high resistance, and thence by wires 15 and,8
to battery. The effect of this is to energize the magnet or solenoid D', operating
the lever L and making contact with the cups 16, 16, and thence by wire 17,
through resistance 18, to the lever V. The resistance 18 is to be made practically
equal to the resistance of the bar J, so that when the current is shifted from the
circuit embracing the resistance 18, there will be no fluctuation in the current
due to the resistance offered by the bar. As soon as the resistance between O
and P is such as to reduce the current in the main circuit passing through the
solenoid D¹ to the permissible amount, the lever K again assumes its normal
position, and the current would now flow as before, through contacts 3, 3, and 5, 5,
to the main circuit, excepting for the fact that the lever Pl being depressed,, and
the contacts 13, 13, closed the solenoid I) is energized, and therefore the circuit
is broken between the cups 5, 5, and completed through cups 16, 16, which throws
in a resistance equal to that of the rod J, and the current therefore now passes
by wire 17, resistance 18, lever V, and through the resistance of the liquid in
tank R and so to the main circuit.
By means of this device, the current from the battery to the main circuit is

page_text: compelled to pass through the liquid resistance in R so long as the plates O.P
are separated beyond a determined distance, said distance being determined by the
position and arrangement of the lever P¹.
By this device there can be no sudden change of the resistance in the circuit,
and thus no jumping of the lights, as would be the case if, when the plates O P
were separated considerably, the solenoid C, nada contact between the cups.3, 3,
thereby suddenly cutting out that resistance and again tending to energize the
solenoid thereby causing a vibration of the latter.
The ball with suitable battery, might be operated through wire 19, contact
point 20 and wire 21, as soon as the lever V was moved to the left. This, of
course, is not essential,
Instead of the solenoids, magnets might be used in some cases. In all cases,
however, it is cssential that the levers shall be released by a less current than
is required to actuate them into their downward position. For illustration,
supposing 100 amperes to be the maximum permissible current, and that
105 amperes are sufficient to draw down the lever K, immediately the contacts 3, 3,
are broken and the contacts 10, 10, made, the resistance of the circuit through J
and O and R will reduce the current to, say 100 amperes. If the lever K
should fail back at this point, it would vibrate rapidly, making and breaking
the circuit. The resistance and weights W, W respectively must be so arranged
that the plates have time to separate before the armature is again released.
Such adjustment is readily made on magnets by determining the distance of
the armature from the magnet at the commencement and end of the stroke. Upon
the gradual return of the plate O to proximity with the plate P provided the
resistance is increased in the circuit it operates, in the first place, to release the
lever K, still forcing the current to pass through the lever V and the tank R, and
finally releases the lever L, when the lever V has returned to its normal position,
which then breaks the circuit through the solenoid D. When, however, the
minimum of the resistance in the tank R is reached, and contact broken
between 13, 13 and made between 5, 5, the current then passes by the wire 6,
through resistance 22, which is made equal to the minimum of the liquid, for a
similar reason as that specified in relation to the resistance 18 so that there is no
sudden variation in the current by this change of the circuit.
The conditions of charge are essentially the same; that is to say, in case the
switch M is closed and the dynamo operated, if an excess of current were being
forced through the battery 1, the solenoid C¹ would again operate and force the
charging current to pass through the resistance of the liquid, which operation will
be readily understood from the previous explanation.
It is obvious that my invention may be carried out in various forms, and that the
character of the source of electricity is immaterial; and that the circuits may be
arranged in many ways. Also, that the liquid resistance may be of different
character, as, for instance, lead plates and dilute sulphuric acid can be employed,
or the reservoir R may be used as an accumulator cell.
The special object of my invention, as will be readily seen, is the prevention of
the excessive rate of charge or discharge of a secondary battery, by interposing a
gradually varying resistance in the circuit by the action of an expanding or
contracting device operated by the heat action of the current passing through it.
Having now particularly described and ascertained the nature of the said
invention 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. The combination with a circuit embracing a secondary battery, of a resistance
device for controlling the amount of current passing through the circuit, and means
comprising an expansion rod for varying the resistance offered to the current,
substantially as specified.
2. A variable rheostat, consisting of relatively separable plates, and an
expansion apparatus, in combination with means for transferring a movement of

page_text: expansion or contraction from the expansion apparatus to a plate, substantially as
specified.
3. The combination in a variable resistance, of a fixed plate, a relatively inovable
plate, a reservoir containing liquid in which the latter plate is movable, an
expansion rod and means operatively connecting said rod with the movable plate,
to cause a movement of the latter upon the expansion or contraction of the rod,
substantially as specified.
4. The combination of the battery B, switch having contact points G F,
variable resistance reservoir R, plates O P, and expansion rod J, said switch "
operating the connections for cutting the rod J into circuit or throwing it out of
circuit, substantially as described.
5. The combination in a switch for varying electric resistance, of an expanding
rod J, operating lever V, the plate O pivoted to the lever V, and the plate P,
both contained in reservoir R, thereby enabling the approach and recession of the
plate O and plate P with substantially constant parallelism of motion, substantially
as described.
6. The combination with an electric circuit of a source of electric energy A, a
control magnet C, a variable resistance R, an expansible apparatus J operated by
beat controlling the resistance R, and a second control magnet D¹ breaking the
direct circuit from the magnet C¹ to line when the resistance R has been increased
to a determined amount, substantially as described.
7. The combination with an electric circuit of the battery B control magnet C',
expansible rod J, resistance chamber B, control magnet D', and the circuits shown
whereby the operation of the magnet D₁ cuts the direct circuit from the battery B
to the line and forces the same to flow through the resistance R, substantially as
described.
8. The combination with an electric circuit of the battery B, control magnet C',
expansible rod J, variable resistance R the lever P1, actuated by the expansion of
the rod J and the second control magnet D¹, said magnet D' breaking the direct
circuit through the magnet C₁ to the line when the rod J has expanded,
substantially as described.
9. The combination with the expansion rod J and the resistance R of the
battery B and magnet C', provided with a double circuit 2 aud 11, the circuit 11
connecting with the expanding rod J operating the resistance R, and the circuit 2
being provided with a resistance 22 practically equivalent to the minimum
resistance of the resistance R between the magnet C and the line, substantially as
described.
10. The combination of the battery B, control magnet C¹, expanding rod J,
resistance R, and the second control magnet D' and the resistances 18 and 22
and the circuits shown, whereby the vibration of the apparatus is controlled,
substantially as described.
دده
3000
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.