US2049635A - Voltage regulating device - Google Patents

Description

Aug. 4, 1936. A. c. TURTLE VOLTAGE REGULATING DEVICE Filed Nov. 25, 1952 4 Sheets-Sheet 1 2, R mwfl m Ev T Z a mfi a an mm mm on x mm ww Aug. 4, 1936. 2,049,635

A. c. TURTLE VOLTAGE REGULATING DEVICE Filed Nov. 25, 19:52 v

4 Sheets-Sheet 2 FIGJB FIGA;

INVENTOB A-CJ'U RTLE AI TORNEY Aug. 4, 1936. A, TURTLE 2,049,635

'VOL'IAGE REGULATING DEVICE Filed Nov. 25, 1952 4 Sheets-Shet s INVENTOR A.C.TURTLE I Y .EWFmm [Z ATTORNEY Aug. 4, 1936. c. TURTLE I 2,049,635 voLTRGE REGULATING DEVICE Filed Ndv. 23, 1952 4 Sheets-Sheet 4 139 1B5 11 i E4 117 n m l IN ENT O R A.O.TURTLE F1614 BY a ATTORNEY Patented Aug. 4, 1936 UNITED STATES PATENT OFFICE 14 Claims.

This invention relates to lamp circuit potential regulating means for car lighting systems. It comprises a specially wound transformer having its secondary winding connected to the terminals of a lamp circuit and its primary winding divided into at least two coils connected in parallel to a source of direct current through a special circuit making and breaking mechanism which functions, in response to a change in potential at the terminals of the direct current source, to effect a compensating change in the timing of the current impulses in one coil with respect to those in the other coil so that the output voltage of the transformer is thereby maintained at an approximately constant value.

In its preferred embodiment the circuit making and breaking mechanism comprises an interrupter in series with each primary coil, each interrupter embodying stationary and rotary contacts, the latter being driven by a suitable D. C. motor connected to the direct current source so that the speed of the motor varies in response to potential changes occurring at the terminals of said source, and means including a governor for automatically varying the angular displacement of the rotary element of one interrupter with respect to the corresponding rotary element of the companion interrupter in response to changes in the speed of the motor.

One particular advantage of this improved regulating means is that it eliminates the exces sive resistance losses introduced in the lighting system by the regulators heretofore employed for the same purpose. Another advantage is that it maintains the potential of the lighting circuit when the potential at the primary source is abnormally low, whereas the regulators heretofore used are efiective only when the potential at the primary source rises above its normal value.

Proceeding now to a more detailed description of the invention, reference will be had to the accompanying drawings, wherein Fig. 1 is a top plan view of a motor driven interrupter assembly adapted to be used in accordance with this invention for automatically varying the phase relation of the primary coils of the transformer.

Fig. 2 is a side elevation of the assembly appearing in Fig. 1.

Fig. 3 is an end elevation of said assembly.

Fig. 4 is a transverse sectional view showing the relative arrangement and mounting of the stationary and rotary contacts of the adjustable interrupter, said view being taken substantially along the line 4-4 of Fig. 2 and certain parts that would otherwise appear being omitted for the sake of clearness.

Fig. 5 is a view in longitudinal section of the rotary elements of the interrupter appearing in 5 Fig. 4.

Fig. 6 is a view in elevation of a fitting employed for connecting the rotary elements of the adjustable interrupter to a governor which determines the angular displacement of said ele- 10 ments.

Fig. 7 is a view in longitudinal section of the rotary element of the remaining or non-adjustable interrupter.

Fig. 8 is a transverse sectional view along the 15 line 8-8 of Fig. 7.

Fig. 9 is a detail perspective view illustrating the construction and mounting of a special switch employed in accordance with this invention.

Fig. 10 is a wiring diagram of a lighting system embodying said invention.

Fig. 11 is a perspective view of a brush and brush housing assembly provided in accordance with this invention.

Fig. 12 is a sectional view taken along the line I 2-42 of Fig. 2.

Fig. 13 is a bottom plan view of a modified interrupter assembly equipped with a spark quenching device.

Fig. 14 is a side elevation of the assembly appearing in Fig. 13.

Referring more particularly to the drawings, ll designates a shaft mounted in suitable bearing brackets l2 carried by a base I3. This shaft carries the rotary contact elements of the interrupters generally indicated at A and B and is driven by a suitable shunt wound direct current motor I 4 of the over-saturated field type, whose operating speed varies according to variations in the potential of the energizing current supplied thereto.

The rotary contact assembly of the interrupter Av is shown in detail in Fig, 5. It comprises a sleeve 15 having an axial bore l6 through which the shaft ll extends. Said sleeve is fitted with a pin I! which works in the spiral shaft slot l8 (see Fig. 1) so that as the sleeve is moved along the length of the shaft it is also turned to vary the angular displacement of the diametrically opposed contacts IS, carried at the outer surface of the sleeve, with respect to the angular displacement of the corresponding contacts 65 of interrupter B. These contacts l9 comprise segments of conducting material fitted (see Fig. 4) 55 between segments 20 of insulating material, said segments being clamped to the outer surface of the sleeve between a shoulder 2| and a clamping nut 22, the inner faces of the shoulder and clamping nut being inclined as at 23 to overlie the mitred ends 24 of the segments whereby the latter are securely held against radial displacement during high speed rotation of the sleeve i5. One end of the sleeve l projects beyond the nut 22 and carries a disc 25 in threaded engagement therewith. The other end of the sleeve projects beyond the shoulder 2i and is rotatably connected to the axially movable end member 26 of the governor generally indicated at 21 in Fig. 1. As shown to advantage in Figs. 5 and 6, said member 26 comprises two halves designated 26a and 261) which embrace the end of the sleeve [5 projecting beyond the shoulder 2i and are fastened together by bolts 28 which engage in an outwardly facing annular groove 29 formed in the sleeve so that the latter is held against axial movement relative to the member 26 but is capable of independent rotary movement.

The two halves of the axially movable governor member 26 are connected by lugs 33 and pivots 3! to corresponding ends of a pair of links 32. The remaining ends of the links 32 are connected by pivots 33 to similar links 34 which, in turn, are connected by lugs 35 and pivots 36 to the remaining end member 3! of the governor, said member Bl being adjustabiy fixed to the shaft I i by the clamping nuts 38 so that the position of this member may be adjusted to regulate the tension of the governor spring 39. From this description it will be apparent that variations in the speed of the motor M and the shaft 1 i in response to changes in the potential of the current supplied to the motor results in the sleeve i5 being moved axially of the shaft in one direction or the other, in the course of which the sleeve is turned about the shaft by means of the pin I? and the groove !8 to change the angular displacement of the contacts l9.

During rotation of the shaft I I the rotary contacts l9 engage successively with four stationary contact brushes 4!, Ma, 4!?) and He made of carbon or other suit-able conductive material. Each brush is slidably mounted in a suitable housing 42 and is pressed inwardly by a. spring 43. The several housings 42 are carried between a pair of supporting plates 44 made of any suitable insulating material, said plates having extensions t5 which, together with an interposed spacer 45, are fastened as at M to an upright 4-8 carried by upper and lower rods 49 mounted in the bearing brackets 52. The housings 42 may be of any suitable construction. As here shown, each housing comprises four metal walls (42a, 42b, 42c and 62d) defining a rectangular guideway 426 in which the brush works, said guideway being open at the inner end of the housing and being closed at the opposite end by a suitable cover plate 42f, the spring 43 being interposed between the cover plate 421 and the outer end of the brush 4 Each brush housing is equipped with a terminal 50 passing therethrough and through suitable apertures in the housing supporting plates 44.

An upright 52 similar to the upright 48 is carried by the previously mentioned rods 48 and serves as a mounting for a switch generally indicated at 53 (see Figs. 1 and 9). The movable contact 54 of this switch is provided with bearings 55 rotatably mounted on the bight portion 56 of a U-shaped bolt. The arms 51 of this bolt pass through suitable openings in the upright 52 and are clamped in place by means of the clamping shoulders and the clamping nuts 59. The movable contact 54 is formed to present plate-like portions 54a and 55b. A spring 60 arranged as shown in Fig. 9 tends to swing the plate portion 54a of contact 54 into engagement with a pair of stationary contact terminals 5! and 62 also carried by the upright 52. The plate portion 54b of contact 54 is equipped with a. terminal 540 and carries a projecting member 5411 made of insulating material. When the various parts are positioned as shown in Fig. l the disc '35 engages the insulating member 5M carried by the movable switch contact 54 and serves to hold the plate portion 5M oi this contact out of engagement with the stationary contact terminals 6! and 52. A particular purpose of this switch will be explained hereinafter.

The movable contact assembly of interrupter B is shown in Figs. '7, 8 and 12. It comprises a metal sleeve 56 carrying at its outer surface a pair of diametrically opposed conducting segments 65 fitted between alternating segments 66 of insulating material, said segments being clamped in place between the shoulder 61 and the clamping nut 53, the ends of the segments being mitred as at 69 to fit the inclined inner edges i of the shoulders 61 and the nut 68. Sleeve 54 is fixed to rotate with the shaft II by means of the set screw H. The rotary contacts 65 of interrupter B co-operate with four brushes 12, 12a, 12b and 520 which are mounted exactly the same manner as brushes 4!, lla, ii?) and Me except that in the case of interrupter B the extensions 45 of the insulating plates 4 between which the brush housings are mounted are fastened to the upright 52.

In describing the operation of the foregoing construction reference will be had to the wiring diagram appearing in Fig. 10. In this figure 80 designates a single core transformer having its secondary winding 8! connected to the terminals 82 of a lamp circuit 83. The primary of the transformer is divided into two coils 84 and 85 each having one terminal connected by conductor 86 and switch 8'! to the negative terminal B8 of a direct current source such as a storage battery 89. The remaining end of coil 84 is connected by conductors 89 to the brushes 4| and ilo of interrupter A. The remaining brushes Mb and Me of this interrupter are connected by conductors 9i and S2 with the stationary contact E! of the automatic switch 53.

The remaining end of coil 85 is connected by conductors 93 to the brushes i2 and 12a of in terrupter B. The two remaining brushes 12b and l'Zc of interrupter B are connected by conductors 94 and 92 to the aforesaid stationary contact 6! of the switch 53.

The positive terminal 88a of the battery 89 is connected through switch 81 and conductors 95 and 95 to the terminals 540 carried by the movable contact 54 of the switch 53. Conductor 95 also connects the positive terminal of the battery to one terminal of the armature start ing resistance 91 and the shunt field 91a of the motor. The remaining terminal of the starting resistance 96 is connected to the positive terminal 98 of the motor M by a conductor 99 which is also connected by a branch conductor l8!) to the stationary terminal 52 of the automatic switch 53. The negative terminals HH of the motor !4 and the negative terminal of the shunt field 91a are connected through conductors I02 and 86 and switch 81 to the negative side of the battery 89. When the motor I4 is at rest the movable contact 54 of switch 53 is held in open position by engagement with the disc 25 as shown to advantage in Fig. 1. With the parts in this position closure of switch 81 causes current to flow from the positive to the negative side of the battery via the conductor 95, the motor starting resistance 91, the motor terminals 98 and MI, the shunt field 91a and the conductors I02 and 86. As the motor attains its normal operating speed the governor 21 acts to move the sleeve I5 and the disc 25 to the left until the movable contact 54 of the switch 53 is free to move into engagement with the stationary contacts 6| and 62 under the influence of the spring 60 thereby closing the automatic switch 53. This closure of switch 53 serves to cut out the motor starting resistance 91 and to cut in the interrupters A and B and the primary coils 04 and 85. With the switch 53 in closed position the flow of current from the positive side of the battery to the motor terminal 98 is via the conductors 95 and 96, switch contacts 54 and 62 and conductors I00 and 99 thus bypassing the starting resistance 91 included in the original circuit. Current also flows in the closed position of switch 53 via conductors 95 and 96, switch contacts 54, 62 and 6| and conductors 9|, 92 and 54 to the brushes 4| b and 4Ic of interrupter A and the brushes 12b and 120 of interrupter B, and thence via the co-operating rotary contacts of the interrupters and the coils 84 and to the negative side of the battery.

The sliding and rotary movement imparted to the sleeve I5 of the interrupter A by the governor 21 as the motor I4 attains its normal operating speed fixes the normal angular displacement of the rotary contacts I9 with respect to the rotary contracts 65. If there is any change of potential at the battery terminals this immediately produces a change in the operating speed of the motor I4. The governor 21 thereupon acts to effect a certain further angular displacement of the sleeve I5 and contacts I9 of interrupter A which results in a change in the timing of the impulses produced in coil 84 with respect to those produced in coil 85 that compensates for the change in the potential of the current supplied to said coils and maintains the output potential of the secondary III at an approximately constant value. In other words, the changes which are made in the angular displacement of the contacts I9 of interrupter A in response to potential variations at the battery terminals serves to advance'or retard the interruptions of the primary circuit including the coil 84 with respect to the interruptions of the parallel primary circuit including the coil 85 so that the effective flux producing ampere turns of the two primary coils remains approximately constant. In this connection it will be understood that the increased or decreased frequency of the interruptions due to changes in the operating speed of the motor I4 are compensated for by an accompanying shortening or lengthening of the duration of the contact periods of the interrupters so that the average voltage in the secondary of the transformer will be maintained approximately constant irrespective of changes in the speed of the operating motor due to changes of potential current at the terminals of the direct current source.

In order to prevent arcing at the interrupter contacts, condensers I05 and I06 may be provided as indicated in Fig. 10. As here shown, condenser I05 is connected across the brushes 4| and 4Ib of the interrupter A while the remaining condenser I06 is connected across the brushes I2 and 12b of the interrupter B.

Reference characters I01 and I08, in Fig. 10, designate a pair of rectifying units shunted across the leads to the primary windings of the transformer to prevent arcing at the interrupter contacts due to the inductive effect of the primary coils. These rectifying units have their output terminals connected to the leads and 93 and their input terminals connected to the lead 86 and are constructed in a well known manner so that, when thus connected, they will offer a high resistance to the flow of current therethrough from the leads 90 and 93 while offering relatively low resistance to the flow of current therethrough in the opposite direction from the primary coils when the latter, due to their inductive effect and to the opening of the primary circuit at the interrupters, are acting as sources of energy that would tend to produce arcing at the interrupter contacts in the absence of the valve action or short circuiting eifect of the rectifiers. A choke coil may be used in connection with the rectifying units as indicated at I09 in order to prevent a too rapid decrease in transformer current.

In Figs. 13 and 14 I have shown a slight modification illustrating the manner in which each interrupter may be equipped with a spark quenching device for reducing arcing at the main interrupter contacts. The interrupter shown in these figures comprises two brushes I I I and II Ia co-operating with the rotary contacts which are the same as described in connection with the previous figures. In this case, how-- ever, the metal sleeve C which carries the rotary interrupter contacts D has one end extended beyond the adjacent brush support 44 and equipped with a metal cam H2 which is electrically connected to the sleeve and serves as a supplementary rotary contact element. This cam H2 has two cam lifts designated I I3 and H4. The cam lift H3 co-operates with a series of metal washers I I5 carried by a lever arm H6. One end of lever arm H6 is pivoted, as at I I1, and is electrically connected to the brush III, as indicated at H8. The other end of the lever arm H6 is apertured for the passage of a screw II 9 and is confined between the screw carried springs I20 and I2I, the tension of which may be regulated by the adjusting nuts I22 and I23. The remaining lift H4 of cam H2 co-operates with a series of washers I24 carried by a lever I25. This lever I25 has its pivoted end I26 electrically connected to the brush HIa as indicated at I2! and its opposite end confined between the springs I 28 and I29 carried by a screw member I30 corresponding tothe previously mentioned screw member I I9.

From the foregoing description it will be understood that thc washers H5 and I24 constitute supplementary contacts in parallel with the brushes III and IIIa which are periodically bridged by the cam II 2 whose cam lifts H3 and I I4 are arranged so that the angular displacement of their points H3a and I I4a is different from that of the main rotary interrupter contacts D. Due to this arrangement it will be seen that when the main interrupter contacts D pass out of engagement with the brushes III and HIa practically no arcing occurs since the primary circuit, including the brushes III and IIIa, is still maintained by reason of the fact that the washers H5 and I24 which are in parallel with these brushes are connected together by the cam II2. As viewed in Fig. 14 the cam rotates in a clockwise direction and the primary circuit is broken when the points I I3a and I Ma of the cam pass out of engagement with the washers I I5 and I24. The springs associated with the free ends of the lever arms H6 and I25 serve to yieldingly maintain the washers H5 and I24 in a position to co-operate with the cam lifts as herein described.

Having thus described my invention, what I claim is:

1. The combination of a transformer having two primary coils connected, in parallel, to a source of direct current and means for changing the timing of the impulses produced in one coil wgh respect to those produced in the other coil to compensate for changes in the potential of the current supplied thereto.

2. The combination of a transformer having two primary coils connected, in parallel, to a source of direct current and means acting in response to potential changes at the terminals of said source for efiecting a compensating change in the timing of the impulses produced in one coil with respect to those produced in the other coil so that the output voltage of the transformer is maintained approximately constant.

3. The combination of a transformer having two primary coils connected, in parallel, to a source of direct current, an interrupter in series with each coil, and means for varying the relative timing of said interrupters in response to changes in the potential supplied to said coils.

4. The combination of a transformer having two primary windings and a secondary winding on a common core, a source of direct current to which the primary windings are connected in parallel, an interrupter in series with each primary winding, and means, responsive to potential variations at said source, for changing the relative timing of the interrupters so that the output potential of the transformer is maintained approximately constant.

5. The combination of a transformer having two primary windings and a secondary winding on a common core, a source of direct current to which the primary windings are connected in parallel, an interrupter in series with each pri-- mary winding, a motor for operating said interrupters connected in circuit with said source so that the speed of the motor is determined by the potential at said source and varies therewith and a governor functioning to automatically vary the timing of one of said interrupters with respect to the timing of the companion interrupter when the speed of the motor varies in response to potential variations at said source.

6. Means for supplying a lamp circuit with alternating current of approximately constant potential from a primary source of variable potential comprising a transformer having a secondary winding and two primary windings on a common core, the secondary winding being included in said circuit, a source of direct current to which the primary windings are connected in parallel, an interrupter in series with each coil and means for varying the relative timing of said interrupters in response to potential variations at said source.

7. The combination with a source of direct current of a transformer having two primary windings connected in parallel to said source and means for producing impulses in said coils including means for variably timing the impulses produced in one coil with respect to those pro- 5 duced in the other coil to regulate the output voltage of the transformer.

8. The combination with a source of direct current of a transformer having two primary windings connected in parallel to said source, an 10 interrupter in series with each coil and means for varying the timing of one interrupter with respect to the timing of the other interrupter to control the output voltage of the transformer.

9. The combination of a transformer having two primary coils connected in parallel to a source of direct current, an interrupter in series with each coil, means for varying the relative timing of said interrupters in response to changes in potential at the terminals of said source, and means connected across the terminals of each coil to prevent arcing at the interrupter contacts due to the inductive effect of the coils when the primary circuits are broken at the interrupters.

10. The combination of a transformer having two primary coils connected in parallel to a source of direct current, an interrupter in series with each coil, a condenser connected in circuit with each interrupter to reduce arcing at the interrupter contacts and means for varying the relative timing of said interrupter in response to changes in potential current at the terminals of said source.

11. The combination with a source of direct current of a transformer having two primary windings connected in parallel to said source, an interrupter in series with each primary winding, a motor for operating said interrupters connected in circuit with said source so that the speed of the motor is determined by the potential at the terminals of said source, a governor functioning to automatically vary the timing of one interrupter with respect to the other interrupter when the speed of the motor varies in response to potential variations at said source, and a switch mechanism functioning automatically to disconnect the interrupters when the motor is at rest and to connect the interrupters in series with their respective primary windings when the motor has attained a predetermined operating speed.

12. The combination with a source of direct current and a load circuit of a transformer having two primary windings connected in parallel to said source and a secondary winding connected to said load circuit, an interrupter in series with each primary winding, a direct current motor for operating said interrupters energized from said direct current source so that the speed of the motor varies in response to potential variation at said source, a governor functioning to automatically change the timing of one interrupter with respect to the remaining interrupter when the speed of the motor varies, a switch arranged to automatically assume an open position when the motor is at rest so as to open circuit the interrupters and the primary windings connected in series therewith, a starting resistance including in the motor circuit, means for automatically closing said switch to include the interrupters and primary windings in circuit with said source and means including said switch for bypassing said starting resistance when the switch is in its closed position.

13. The combination with a transformer and a source of direct current included in the primary circuit of the transformer of interrupter means functioning, in response to changes in the potential at said source, for efiecting a compensating change in the interruptions of said circuit so that the output voltage of the transformer is thereby maintained at an approximately constant value.

14. In a. system of electrical distribution the combination of a direct current source, a load circuit, means including an adjustable interrupter for connecting said circuit to said source whereby an alternating current is produced in said circuit, a direct current motor connected to said source to operate at a speed proportionate to the voltage across the terminals of said source and means actuated by said motor for adjusting the interrupter to maintain the voltage of the load circuit at a substantially constant value throughout a wide range of voltage variations at the terminals of said source.

ALFRED C. TURTLE.

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