US720305A - Current-regulator. - Google Patents

Current-regulator. Download PDF

Info

Publication number
US720305A
US720305A US8592201A US1901085922A US720305A US 720305 A US720305 A US 720305A US 8592201 A US8592201 A US 8592201A US 1901085922 A US1901085922 A US 1901085922A US 720305 A US720305 A US 720305A
Authority
US
United States
Prior art keywords
core
coil
regulator
current
movable
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US8592201A
Inventor
James J Wood
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to US8592201A priority Critical patent/US720305A/en
Application granted granted Critical
Publication of US720305A publication Critical patent/US720305A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • GPHYSICS
    • G05CONTROLLING; REGULATING
    • G05FSYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES
    • G05F1/00Automatic systems in which deviations of an electric quantity from one or more predetermined values are detected at the output of the system and fed back to a device within the system to restore the detected quantity to its predetermined value or values, i.e. retroactive systems
    • G05F1/10Regulating voltage or current
    • G05F1/12Regulating voltage or current wherein the variable actually regulated by the final control device is ac
    • G05F1/14Regulating voltage or current wherein the variable actually regulated by the final control device is ac using tap transformers or tap changing inductors as final control devices

Definitions

  • WITNESSES %w V By AZ/arneys
  • n uonms'rirzns cc. womumou WASHINGTON c UNITED STATES PATENT OFFICE.
  • My invention aims to provide an improved current-regulator for maintaininga substantially constant current on an alternating-circuit such as that used for arc-lamps, and in which the regulator has less weight and is much more compact than those heretofore in use.
  • My invention aims to provide also an improvement in such regulators, whereby the, operation is rendered more certain.
  • My invention aims also to provide an im-' provement in such regulators which avoids. the necessity of the usual dash-pot for cushioning the shock of the movable parts when the current is cut of or changed.
  • My invention aims to provide also various improvements in detail,which are hereinafter referred to.
  • Figure 1 is a vertical section through the casing of one of my improved regulators, showing the same in face view.
  • Fig. 2 is a similar figure showing the regulator in edge view.
  • Fig. 3 is a plan of the regulatorin its casing, the cover of the latter being removed.
  • Figs. 4, 5, and 6 are diagrammatic illustrations showing the operation of the regulator.
  • Fig. 7 is a diagrammatic illustration of another embodiment of the invention.
  • Fig. 8 is a diagram of an entire circuit..
  • Fig. 9 is a section of the coil.
  • My current-regulator includes a reactance devicesuch, for example,as the usual core with a coil surrounding the same and movable longitudinally thereof, the coil being in the circuit whose current is to be regulated. As the current increases or decreases,the coil moves farther onto or off of the core, the latter choking the currentin proportion to'the distance to which itenters into the coil. Either the coil or the core, orboth, may be movable, it being only necessary that one shall be movable relatively to the other. It is common to have the core fixed and the coil movable and to counterbalance the coil by a lever which carries a weight at its opposite end.
  • a counterbalance which is arranged to move in the same vertical line with such movable part and which may be a weight and may be connected by a lever connection with such movable part.
  • the counterbalance is preferably arranged so as to evenly balance the movable member of the reactance device when the current is cut oif.
  • I preferably use a pair of levers connected to the movable part at opposite sides thereof and preferably extending side by side across the regulator, so that they pass each other and have their counterbalanced ends adjacent to the side of the movable member opposite to that to which they are attached.
  • the coil and the core are arranged to counterbalance each other.
  • A indicates a coil, and B a core, each being of any well-known or suitable construc tion, such as that shown.
  • the coil and core are both movable, being supported from a fixedsupport C.
  • a lever connection is provided between the two, so that when there is no current they balance each other, with the coil in its uppermost position relatively to the core, as shown in Fig. 4, and so that as the current is introduced and increases the tendency of the coil to move down upon the core is properly counteracted by the weight of the core, so that the amount of choking to which the current is subjected is just sufficient to maintain the current constant, whatever may be the load. Under maximum load the position of the parts is practically that shown in Fig.
  • a pair of levers D and E is used, connected, respectively, to opposite sides of the coil 'A, as by means of links F and G, and eachextending across the coil and connected at its opposite or counterbalance end to the core B, as by means of links H and J, respectively.
  • the fulcrums K and L of the respective levers are carried upon the support C at such a distance from the ends of the lovers as shall be in proper proportion to the weights of the coil and core.
  • the levers may be adjusted in the fulcrumblocks by means of their fastening-screws to vary the lengths of the respective lever-arms.
  • the position of the ends of each lever relatively to the fulcrum is such as to change the leverage of the core with respect to the coil as the current changes, so as to compensate for the varying pull of the magnetic reaction.
  • the leverage of the core increases continuously from the position of minimum to that of maximum current.
  • 0c, 00', and 00 indicate the effective lengths of the lever-arm from which the coil is suspended, which varies but slightly for the minimum, middle, and maximum, while y, y, and g indicate the effective lengths of the lever-arm from which the core is suspended, which increases continuously from the first to the last position.
  • the two levers are arranged symmetrically with respect to each other and balance each other, so as to give a direct vertical movement of both the coil and the core.
  • FIG. 7 A regulator in which the counterbalance is separate from the members of the reactance device and which embodies my broad invention is illustrated in Fig. 7, the lever E being omitted for the sake of clearness.
  • I have supposed the coil A movable and the core 13 fixed.
  • the counterbalance instead of being the core is a separate weight M.
  • I have illustrated the same sort of lever connection to this counterweight as to the core B in the previous figures; but it is understood that the connection also may be varied without departure from the invention and may consist of any means for transmitting movement from the movable member to the counterbalance.
  • a weight M immediately below the reactance device I may arrange a weight or weights in many other positions in which the center of gravity moves in substantially the same vertical line with the center of the movable parts of the reactance device.
  • a feature of my invention which is of considerable value is the forming of the core with approaching poles, which reduce and localize the air-gap through which the coil moves, and which thus concentrate the magnetic flux and render the operation more uniform.
  • the core B is W-shaped, as shown, and the poles of the center and outer legs approach each other, as shown at N.
  • I provide also a very convenient arrangement for supporting the operative parts of the regulator in a casing, whereby they are suspended from the side walls, preferably near the top thereof, so as to be convenient of access for insertion or removal and so that the entire regulator may be lifted bodily out of the casing.
  • I preferably arrange the support 0 so that it extends across between the side walls of the casing O, which latter carries sockets P for receiving the ends of said support.
  • the levers which connect the movable member of the regulator with its counterbalance are fulcrumed upon the support 0, so that as the support is lifted out of the surrounding casing the movable member and its counterweight, or, in the form illustrated, all the operative parts, are lifted out of the casing.
  • a cover Q may be attached to the casing by means of screws R, the heads of which are adapted to be attached to any suitable suspending means.
  • the combination of the vertically-moving coil and core and the differential compensating levers results in a structure which in operation instantly adapts itself to a change of current by a dead-beat movement without over compensation or oscillation, so that a dash-pot or other steadying means is unnecessary.
  • the utilization of the core itself as a counterweight is an important feature of my invention, contributing greatly to the compactness of the apparatus andreducing the total weight.
  • the position of the support relatively to the other parts and the curve in the levers D and E permits of their ends swinging in so close to the verticalline through the supportsas shown, for example, in Fig. 4-as to produce an enormous change in the ratio of the effective lengths of the leverarms of the weight and coil, respectively, from one extreme position to the other.
  • the coil A may be variously connected in the circuit. I have shown it as provided with flexible cables S S passing out through the side of the casing. To admit of adjustment to varying conditions, the coil may be divided into sections connected by wires a b c, &c.,
  • the object of thus looping out the coil at several difierent points is to adjust the same for an increased or diminished voltage, current, or frequency above or below normalthat is to say, if for any reason the voltage of the circuit should be increased or the frequency reduced, then in order to maintain the current constant at a predetermined amount it will be necessary to cut in a greater number of coils, or, if the voltage is reduced or the frequency increased, to cut out coils.
  • This is an especially advantageous feature of my improved automatic regulator, since it enables the current to be regulated without introducing wasteful impedance under maximum load, and hence without reducing the power factor.
  • one of the leads, T, coming directly from the generator U, is connected to the zero-terminal 1, while the other lead, V, coming from the generator through a number of lamps W, is connected to the terminal 4, so as to adapt the apparatus for use with a voltage intermediate between the maximum and the minimum for which the device is designed.
  • a current-regulator comprising a coil and a core movable relatively to each other, the combination with a movable member of said regulator, of a counterbalance therefor arranged to move in substantially the same vertical line therewith, and a differential connection between said movable member and said counterbalance adapted in operation to vary the tendency of said movable member to separate from its complementary member so that the same shall increase progressively as the regulator departs from the position of maximum load.
  • a current-regulator comprising acoil and a core movable relatively to each other, the combination with a movable member of said regulator, of a counterbalance therefor, and a pair of difierential compensating levers connected to said movable member at opposite sides thereof and to said counterbalance, and adapted in operation to vary the tendency of said parts to separate by reason of their weight so that the same shall increase progressively as the regulator departs from the position of maximum load.
  • a current-regulator comprising acoil and a core movable relatively to each other, the combination with a movable member of said regulator, of a counterbalance therefor, and a pair of levers connected to said movable member at opposite sides thereof, extending side by side across said movable member, and connected at their other ends to said counterbalance.
  • a current-regulator the combination of a coil, a core, and a pair of levers each of which is connected at one end to one side of said coil and at its other end to the opposite side of said core.
  • a current-regulator the combination of a coil and a core, the one movable relatively to the other, said core havingapproaching poles whereby to reduce and localize the air gap, and a differential compensating means adapted to exert upon the movable member a separating force which progressively increases as the coil and core are attracted together.
  • a current-regulator the combination of a coil and a core differentially counterbalancing each other, the core being arranged below the coil so as to be separated therefrom by a downward movement.
  • a current-regulator comprising a coil and a core movable relatively to each other, the combination with a movable member of said regulator, of a counterbalance therefor arranged to move in substantially the same vertical line with said movable member, and a lever connecting said movable member and said counterbalance, said lever having its counterbalance-arm curved downwardly.
  • a current-regulator for maintaining a constant current comprising in combination a coil and a core movable relatively to each ICC other whereby to maintain a constant curmy name in the presence of two subscribing rent, a series of terminals, and separate conwitnesses. nections from said terminals to diiferent points of said coil whereby to adjust the num- JAMES 5 ber of turns of the coil in said circuit to vary witnesseses:

Description

PATEN'IED FEB. 10. 1903.
J. J. WOOD. CURRENT REGULATOR. -APPLICATION FILED DEO.14, 1901.
N0 MODEL.
,G'Qwm (C50 WITNESSES:
PATENTBD. FEB. 10, 1903.
J. J. WOOD.
CURRENT REGULATOR.
APPLICATION FILED DEG. 14, 1901.
s sums-51131;"! 2
10 MODEL.
INVENTOR;
By Aztameys, r V
WITNESSES:
No- 72 .s05. PATENTBD FEB. 10, 1903.
' J. J. WOOD.
CURRENT REGULATOR.
APPLICATION FILED DEC. 14, 1901.
H0 IODEL. 3 SHEETS-SHEET 3.
FIG. .9.
INVENTOR:
WITNESSES: %w V By AZ/arneys,
n: uonms'rirzns cc. womumou WASHINGTON c UNITED STATES PATENT OFFICE.
JAMES J. WOOD, OF FORT IVAYNE, INDIANA.
CURRENT-REGULATOR.
SPECIFICATION forming part of Letters Patent N 0. 720,305, dated February 10, 1903. Application filed December 14,1901. Serial No. 85,922. (No model.)
To (0Z5 whom it may concern:
Be itknown that I, JAMEs J. WOOD, a citizen of the United States, residing at Fort Wayne, in the county of Allen, State of Indiana, have invented cer-tain new and useful Improvements in Current-Regulators, of which the following is a specification.
My invention aims to provide an improved current-regulator for maintaininga substantially constant current on an alternating-circuit such as that used for arc-lamps, and in which the regulator has less weight and is much more compact than those heretofore in use.
My invention aims to provide also an improvement in such regulators, whereby the, operation is rendered more certain.
My invention aims also to provide an im-' provement in such regulators which avoids. the necessity of the usual dash-pot for cushioning the shock of the movable parts when the current is cut of or changed.
My invention aims to provide also various improvements in detail,which are hereinafter referred to.
Referring to the accompanying drawings, illustrating embodiments of my invention, Figure 1 is a vertical section through the casing of one of my improved regulators, showing the same in face view. Fig. 2 is a similar figure showing the regulator in edge view. Fig. 3 is a plan of the regulatorin its casing, the cover of the latter being removed. Figs. 4, 5, and 6 are diagrammatic illustrations showing the operation of the regulator. Fig. 7 is a diagrammatic illustration of another embodiment of the invention. Fig. 8 is a diagram of an entire circuit.. Fig. 9 is a section of the coil.
My current-regulator includes a reactance devicesuch, for example,as the usual core with a coil surrounding the same and movable longitudinally thereof, the coil being in the circuit whose current is to be regulated. As the current increases or decreases,the coil moves farther onto or off of the core, the latter choking the currentin proportion to'the distance to which itenters into the coil. Either the coil or the core, orboth, may be movable, it being only necessary that one shall be movable relatively to the other. It is common to have the core fixed and the coil movable and to counterbalance the coil by a lever which carries a weight at its opposite end. Accord ing to myinvention I provide a counterbalance which is arranged to move in the same vertical line with such movable part and which may be a weight and may be connected by a lever connection with such movable part. The counterbalance is preferably arranged so as to evenly balance the movable member of the reactance device when the current is cut oif. For compactness I preferably use a pair of levers connected to the movable part at opposite sides thereof and preferably extending side by side across the regulator, so that they pass each other and have their counterbalanced ends adjacent to the side of the movable member opposite to that to which they are attached. In the simplest embodiment of my invention and most compact the coil and the core are arranged to counterbalance each other.
Referring now to the accompanying drawings, A indicates a coil, and B a core, each being of any well-known or suitable construc tion, such as that shown. In Figs. 1 to 6 the coil and core are both movable, being supported from a fixedsupport C. A lever connection is provided between the two, so that when there is no current they balance each other, with the coil in its uppermost position relatively to the core, as shown in Fig. 4, and so that as the current is introduced and increases the tendency of the coil to move down upon the core is properly counteracted by the weight of the core, so that the amount of choking to which the current is subjected is just sufficient to maintain the current constant, whatever may be the load. Under maximum load the position of the parts is practically that shown in Fig. 4, the downward attraction of the core being very slight and ap proximately such as to bring its lower edge even with the lower edge of the pole-faces of the core. Preferably a pair of levers D and E is used, connected, respectively, to opposite sides of the coil 'A, as by means of links F and G, and eachextending across the coil and connected at its opposite or counterbalance end to the core B, as by means of links H and J, respectively. The fulcrums K and L of the respective levers are carried upon the support C at such a distance from the ends of the lovers as shall be in proper proportion to the weights of the coil and core. The levers may be adjusted in the fulcrumblocks by means of their fastening-screws to vary the lengths of the respective lever-arms. The position of the ends of each lever relatively to the fulcrum is such as to change the leverage of the core with respect to the coil as the current changes, so as to compensate for the varying pull of the magnetic reaction. As shown in Figs. 4, 5, and 6, the leverage of the core increases continuously from the position of minimum to that of maximum current. In these figures, 0c, 00', and 00 indicate the effective lengths of the lever-arm from which the coil is suspended, which varies but slightly for the minimum, middle, and maximum, while y, y, and g indicate the effective lengths of the lever-arm from which the core is suspended, which increases continuously from the first to the last position. The two levers are arranged symmetrically with respect to each other and balance each other, so as to give a direct vertical movement of both the coil and the core.
A considerable degree of compactness and simplicity as compared with prior constructions may be obtained by applying the idea of my invention in other ways than in that shown in Figs. 1 to 6. A regulator in which the counterbalance is separate from the members of the reactance device and which embodies my broad invention is illustrated in Fig. 7, the lever E being omitted for the sake of clearness. In this case I have supposed the coil A movable and the core 13 fixed. The counterbalance instead of being the core is a separate weight M. I have illustrated the same sort of lever connection to this counterweight as to the core B in the previous figures; but it is understood that the connection also may be varied without departure from the invention and may consist of any means for transmitting movement from the movable member to the counterbalance. Instead of a weight M immediately below the reactance device I may arrange a weight or weights in many other positions in which the center of gravity moves in substantially the same vertical line with the center of the movable parts of the reactance device.
A feature of my invention which is of considerable value is the forming of the core with approaching poles, which reduce and localize the air-gap through which the coil moves, and which thus concentrate the magnetic flux and render the operation more uniform. Preferably the core B is W-shaped, as shown, and the poles of the center and outer legs approach each other, as shown at N. I provide also a very convenient arrangement for supporting the operative parts of the regulator in a casing, whereby they are suspended from the side walls, preferably near the top thereof, so as to be convenient of access for insertion or removal and so that the entire regulator may be lifted bodily out of the casing. For this purpose I preferably arrange the support 0 so that it extends across between the side walls of the casing O, which latter carries sockets P for receiving the ends of said support. As explained above, the levers which connect the movable member of the regulator with its counterbalance are fulcrumed upon the support 0, so that as the support is lifted out of the surrounding casing the movable member and its counterweight, or, in the form illustrated, all the operative parts, are lifted out of the casing. A cover Q may be attached to the casing by means of screws R, the heads of which are adapted to be attached to any suitable suspending means.
Though I have described with great particularity of detail apparatus embodying my invention, yet it is to be understood that my invention is not limited to the particular embodiments shown and described. Various modifications of the same in the details and in the arrangement and combination of the parts are possible to those skilled in the art without departure from the invention.
The combination of the vertically-moving coil and core and the differential compensating levers results in a structure which in operation instantly adapts itself to a change of current by a dead-beat movement without over compensation or oscillation, so that a dash-pot or other steadying means is unnecessary. The utilization of the core itself as a counterweight is an important feature of my invention, contributing greatly to the compactness of the apparatus andreducing the total weight. The position of the support relatively to the other parts and the curve in the levers D and E permits of their ends swinging in so close to the verticalline through the supportsas shown, for example, in Fig. 4-as to produce an enormous change in the ratio of the effective lengths of the leverarms of the weight and coil, respectively, from one extreme position to the other. It is only by such an enormous change that the counterbalance can cause a truly constant current under all loads. In prior devices employing straight-armed levers it is impossible to obtain the same change of ratio between the extreme positions, and the regulation is correspondingly imperfect. This effect is also assisted by the short lever-arm, which I am enabled to use by reason of the heaviness of the core and by the arrangement of this arm to turn through an arc, such that its point of connection with the core swings from nearly under the fulcrum to nearly level therewith.
The coil A may be variously connected in the circuit. I have shown it as provided with flexible cables S S passing out through the side of the casing. To admit of adjustment to varying conditions, the coil may be divided into sections connected by wires a b c, &c.,
to terminals 1 2 3, &c., Fig. 1, to one or other of which the cables may be connected. This matter will be understood best from the diagram of the entire circuit in Fig. 8 and the section of the coil in Fig. 9. According to the manner of winding shown in Fig. 9 the wire ct is wound in any desired number of layers around the spool and terminates finally in the wire f. From the outer layer may be taken connecting-wires b, c, d, and e at any desired intervals. In actual use, for example, I may provide six hundred turns between the wire a and the wire I) and twenty-five additional turns between each of the succeeding wires. The object of thus looping out the coil at several difierent points is to adjust the same for an increased or diminished voltage, current, or frequency above or below normalthat is to say, if for any reason the voltage of the circuit should be increased or the frequency reduced, then in order to maintain the current constant at a predetermined amount it will be necessary to cut in a greater number of coils, or, if the voltage is reduced or the frequency increased, to cut out coils. This is an especially advantageous feature of my improved automatic regulator, since it enables the current to be regulated without introducing wasteful impedance under maximum load, and hence without reducing the power factor. In the circuit of Fig. 8 one of the leads, T, coming directly from the generator U, is connected to the zero-terminal 1, while the other lead, V, coming from the generator through a number of lamps W, is connected to the terminal 4, so as to adapt the apparatus for use with a voltage intermediate between the maximum and the minimum for which the device is designed.
I claim as my invention 1. In a current-regulator comprising a coil and a core movable relatively to each other, the combination with a movable member of said regulator, of a counterbalance therefor arranged to move in substantially the same vertical line therewith, and a differential connection between said movable member and said counterbalance adapted in operation to vary the tendency of said movable member to separate from its complementary member so that the same shall increase progressively as the regulator departs from the position of maximum load.
2. In a current-regulator, the combination of a coil and a core movable in a vertical line relatively to each other, and a differential connection between them so that each receives a part of the total movement which at the position of maximum load is substantially in inverse proportion to its weight, the tendency of said parts to separate by reason of their weight and manner of connection being increased progressively as the regulator departs from the position of maximum load,
3. In a current-regulator, the combination of a coil and a core movable in a vertical line relatively to each other, and connected to each other by differential compensating levers adapted in operation to vary the tendency of said parts to separate by reason of their weight so that the same shall increase progressively as the regulator departs from i the position of maximum load.
4. In a current-regulator comprising acoil and a core movable relatively to each other, the combination with a movable member of said regulator, of a counterbalance therefor, and a pair of difierential compensating levers connected to said movable member at opposite sides thereof and to said counterbalance, and adapted in operation to vary the tendency of said parts to separate by reason of their weight so that the same shall increase progressively as the regulator departs from the position of maximum load.
5. In a current-regulator comprising acoil and a core movable relatively to each other, the combination with a movable member of said regulator, of a counterbalance therefor, and a pair of levers connected to said movable member at opposite sides thereof, extending side by side across said movable member, and connected at their other ends to said counterbalance.
6. In a current-regulator, the combination of a coil, a core, and a pair of levers each of which is connected at one end to one side of said coil and at its other end to the opposite side of said core.
'7. In a current-regulator, the combination of a coil and a core, the one movable relatively to the other, said core having approaching poles whereby toreduce and localize the air-gap.
8. In a current-regulator, the combination of a coil and a core, the one movable relatively to the other, said core havingapproaching poles whereby to reduce and localize the air gap, and a differential compensating means adapted to exert upon the movable member a separating force which progressively increases as the coil and core are attracted together.
9. In a current-regulator, the combination of a coil and a core differentially counterbalancing each other, the core being arranged below the coil so as to be separated therefrom by a downward movement.
10. In a current-regulator comprising a coil and a core movable relatively to each other, the combination with a movable member of said regulator, of a counterbalance therefor arranged to move in substantially the same vertical line with said movable member, and a lever connecting said movable member and said counterbalance, said lever having its counterbalance-arm curved downwardly.
11. In combination with a circuit carrying alternating-current-translating devices in series, a current-regulator for maintaining a constant current comprising in combination a coil and a core movable relatively to each ICC other whereby to maintain a constant curmy name in the presence of two subscribing rent, a series of terminals, and separate conwitnesses. nections from said terminals to diiferent points of said coil whereby to adjust the num- JAMES 5 ber of turns of the coil in said circuit to vary Witnesses:
the current therein. A. L. HADLEY,
In witness whereof I have hereunto signed T. W. BEHAN.
US8592201A 1901-12-14 1901-12-14 Current-regulator. Expired - Lifetime US720305A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US8592201A US720305A (en) 1901-12-14 1901-12-14 Current-regulator.

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US8592201A US720305A (en) 1901-12-14 1901-12-14 Current-regulator.

Publications (1)

Publication Number Publication Date
US720305A true US720305A (en) 1903-02-10

Family

ID=2788820

Family Applications (1)

Application Number Title Priority Date Filing Date
US8592201A Expired - Lifetime US720305A (en) 1901-12-14 1901-12-14 Current-regulator.

Country Status (1)

Country Link
US (1) US720305A (en)

Similar Documents

Publication Publication Date Title
US720305A (en) Current-regulator.
US2324370A (en) Voltage regulator
US765948A (en) Current-regulator.
US772096A (en) System of electrical distribution.
US2064621A (en) Electrical control apparatus
US2217406A (en) Voltage regulator
US502788A (en) Regulator for electric generators
US2246306A (en) Regulator
US696427A (en) Electric indicating instrument.
US783514A (en) Regulator.
US726234A (en) Automatic potential-regulator.
US1381283A (en) Electrical regulating system
US1305970A (en) Car-lighting system
US725800A (en) Automatic potential-regulator.
US684165A (en) Method of regulating electric circuits.
USRE23148E (en) Means for regulating a machine
US762671A (en) Automatic potential-regulator.
US1165928A (en) Power-factor regulator.
US949151A (en) Electric-arc lamp.
US1466258A (en) Electrical regulator
US728034A (en) Regulator for electric currents.
US839713A (en) Electric regulator.
US1118333A (en) Electric regulator.
US1596505A (en) Electric regulator
US1673718A (en) Electric regulator