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Publication numberUS2767369 A
Publication typeGrant
Publication dateOct 16, 1956
Filing dateApr 1, 1953
Priority dateApr 1, 1953
Publication numberUS 2767369 A, US 2767369A, US-A-2767369, US2767369 A, US2767369A
InventorsCarl Schindler
Original AssigneeMcgraw Electric Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Control means and system of control
US 2767369 A
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Description  (OCR text may contain errors)

Oct. 16, 1956 c. SCHINDLER 2,767,369

CONTROL MEANS AND SYSTEM OF CONTROL Filed April l, 1951? 2 sheets-sheet 1 JNVENTOR. f2 2 car; weal-mozzar- Oct. 16, 1956 e. SCHINDLER 2,767,369

CONTROL MEANS AND SYSTEM OF CONTROL Filed April 1,. 1953 2 Sheets-Sheet 2 INVENTOR. Car'Z 62h irzdZer United States Patent Cari Schindler, Wauwatosa, Wis., Electric Company, Milwaukee, Delaware Application April 1, 1953, Serial No. 346,065 13 Claims. (Cl. 32343.5)

assignor to McGraw Wis., a corporation of This invention relates to control means and to a system of control and is particularly directed toa system of voltage control, though it is to be understood that in its broader aspect this invention can be followed in the control of different quantities.

It is an object of the present invention to provide a system of control responsive to voltage fluctuations, and which includes a hydraulically operated servo mechanism, which is self-compensating to permit the actuating mechanism to float at normal or neutral position with a minimum amount of hunting.

It is another object of this invention to provide a control means and system of control for use in voltage regulation, and which is readily adaptable for use in actuating as current, reactive volt amperes', or power.

Specifically, it is an object of the present invention to provide an electrical servo mechanism which does not frictionally actuated slip lever.

Further objects and advantages of the present inventhe control means.

Fig. 3 is a sectional view of another embodiment of the working cylinder member of the control means.

Referring to Fig. l, a transformer has been indicated generally by the reference character 1. It is provided with a primary 2 and a secondary 3 connected, respectively, to the power line 4 and the load line 5. A tap changer indicated generally by the reference character 6 is provided on the primary side of the transformer. This tap changer 6 is preferably of the multiple point, snap action type very commonly and widely used.

A voltage sensitive device in the form of an electromagnetic solenoid coil is electrically connected across the load or secondary line 5, and is generally denoted by the reference character 7. It will be apparent from the hereinafter description that the sensitive device may take any of various forms, such as current transformers, DArsonval instruments, and the like (not shown), which may be made responsive to current, reactive volt amperes, or power. As presently described, the device takes the form of a voltage coil 8 arranged to receive a magnetic plunger or armature 9, fastened at its upper end to a zero adjustat its lower end to a pivot pin 11.

The armature 9 may be made of a temperature sensitive magnetic alloy, commonly used for devices of this nature where ambient temperatures might alfect the delicate response of the voltage sensitive device. Temperature compensator alloys are generaly of iron-nickel alloys and ave their magnetic permeability proportional to change in temperature.

The pivot pin 11 is attached to the operating end 12 of an actuating member or cantilever 13 which is rotatably response to voltage fluctuation at a maximum sensitivity, the cantilever 13 is preferably mounted on ball or roller bearings 15 on the shaft 14.

The outer end 16 of the cantilever is arranged to receive one end of compensating springs 17 and 18, which are fastened at their opposite ends to a compensating lever 19 rotatably supported on the supporting shaft 14, and 20 and 2-1. This may be clearly compensating lever 19 is biased 1n an axial direction relative to the shaft 14 by means of a compression spring 23 engaging a slidable friction plate 24, which abuts the lever 19, forcing it towards frictional engagement with a crank 25. The crank 25 is also rotatably mounted on the shaft 14 and is provided with a. flange 26 which acts as a stop for the spring 23. The crank is pivotally connected to a link 27 which, in turn, is pivotally attached to a yoke 28 having opposed pistons 29 received by of the working cylinder bores are each closed at one end and communicate only through a slide valve, which is denoted generally by the reference character 35.

The slide valve includes outlet ports 36 and 37 comits ends. portion 41 is open and close the inlet port 42, communicating with a pump 43 arranged to supply oil or other hydraulic fluid under pressure. The slide member 40 is operatively asoperating end 12 of the cantilever member 13 by means of a pivoted link member 44.

It is to be understood that the entire mechanism may be immersed in oil, if so desired, and that the same oil maybe used as the hydraulic media. When so immersed, the unit will not have the tendency to become airbound. The pump is shown here diagrammatically, but it is to be understood that it may take any of various forms, and if tion or the operation of the control means. The slide valve 35 communicates with working cylinder member 34 through the ports 45 and, 46, respectively. 28 is connected at its upper end to a con-tact actuator, which may take the form of a U-shaped trunnion 47 supporting a pivot pin 48, which is rotatably connected to an actuating linkage 49. The actuating linkage 49 is operatively connected to the snap action tap changer 6, so that to drop downwardly with respect to the solenoid, as shown in Fig. 1'. It will be" noted that the plunger 9 is resiliently supported at its top by means of a zero adjustment screw 10. This downward movement of the plunger will cause the cantilever 13 to rock in a counterclockwise direction about the shaft 14, and will simultaneously cause the link member 44 to move downwardly. The counterclockwise movement of the cantilever will draw the compensating spring 18 in tension against an equalizing compressive action on the compensating spring 17. The compensating lever 19 will, accordingly, be biased towards counterclockwise motion about the shaft 14.

The simultaneous downward motion of the link member 44 will actuate the slide member 40 of the slide valve 35 towards a downward direction, as viewed in Fig. l. The downward motion of the slide member 4% will open the outlet port 37 by the sliding action of the gate member 39 and also open the inlet port 42 by the sliding action of the integral gate portion 41. It will be noted that there is a free passageway above the lower piston 31 through the port 46 and out the inlet port 37, permitting unimpeded movement of the lower piston 30 in either direction.

The hydraulic fluid, which is under pressure transmitted by the pump 43, will be forced through the port 45 into the bore 32 of the working cylinder member 34. This pressure will be imparted to the upper piston 29, causing a simultaneous upward movement of the yoke 28 and the actuating linkage 49 through the trunnion 47. It will be apparent that such upward motion will cause the tap changer 6 to raise the voltage on the load line or secondary line responsive to the position of the contacts connected to the primary 2 of the transformer 1.

Referring again to the upward motion of the yoke 28, this movement, which occurs simultaneously with the change of taps, will be imparted to the link 27 pivotally attached to the crank 25. The upward motion of the link 27 will tend to cause the crank 25 to rotate about the shaft 14 in a clockwise direction. Attention is drawn to the fact that the crank frictionally engages the compensating lever 19, which lever has been previously biased towards a counterclockwise direction about the shaft 14 by means of the action of the compensator springs 17 and 18 responsive to the motion of the outer end 16 of the cantilever 13. The compensating lever 19 is prevented from excess rotational movement by means of the stops 20 and 21 engageable therewith.

The immediate effect of the compensating mechanism is to reduce overtravcl of the piston 29 to cause the tap changer to move beyond the desired degree of regulation. Obviously, this will reduce wear and tear on the regulator and switch taps in addition to reducing unnecessary voltage fluctuation and flickering of electric lamps on the regulated circuit. The compensating device also permits the mechanism to float between taps as long as the normal voltage exists. The compensating lever 19 is nothing more than a slip lever frictionally contacting the crank 25, permitting the floating action no matter which tap might be engaged by the tap changer switch blade. The frictionally driven lever and the compensating spring connection will tend to slip past the crank after a period of time has expired when the tap change has been completed, to permit the mechanism to float at the new position and supply normal secondary voltage. It will be apparent that the positions of compensation may be determined by the size and force exerted by the compensating springs 17 and 18.

When normal secondary voltage has been restored, th s voltage will be immediately reflected in the voltage sensitive device 7, causing the zero adjusted plunger 9 to seek its normal operating position. The normal operating position will be immediately reflected in the slide member 40 to close the inlet port 42 and the outlet ports 36 and 37. This ac 'on will permit an equihbrium condition to exist between the pistons 29 and 30 responsive to the compensation provided by means of the lever 19 and the crank 25.

It will be apparent that the device will operate in substantially the same manner as above described when an overvoltage condition exists. The existence of an overvoltage will be reflected in the voltage sensitive device 7 to cause the plunger 9 to move in an upward direction with a consequent opening of the inlet port 42 to permit the pressurized hydraulic fluid to enter the port 46 to the bore 33 of the working cylinder member 34, which will force the piston 30 in a downward direction and concurrently operating'the tap changer to move to a lower voltage tap position. The port 45 will permit any trapped fluid to escape out through the opened outlet port 36 for unimpeded motion of the upper piston 29. The same compensating effect will take place between the lever 19 in the crank 25, but in an opposite direction about the shaft 14 than as described in connection with undervoltage conditions in the load or secondary 5. The device will then float at the new tap with a minimum of hunting between taps as compensated for between the members 19 and 25.

The preferred embodiment of the control means has been described in connection with a dual-chamber cylinder supplying pressure to two independently operable piston members each joined to a linking yoke. However, the device may conveniently take the form illustrated by Fig. 3 without departing from the scope of invention.

Like parts relating to both embodiments bear the same reference character in each of the figures of the drawings. The embodiment of Fig. 3 is illustrative of a single piston 50 having dual working faces, and which is axially slidable in the bore 51 of the working cylinder member 52. The working cylinder member is closed at both ends except for an opening in each end sealed by means of gaskets 53 and 54, respectively. The gaskets 53 and 54 are arranged to receive piston rods 55 and 56, respectively. The rods 55 and 56 extend from either face of the piston member 50 and are joined at their outer ends to pivot trunnions 47 and 57, respectively. Ports 45 and 46 provide an entrance and an exit means for the pressurized hydraulic fluid, which is alternatively admitted and expelled in substantially the same manner as described in connection with the preferred embodiment. The compensating means, which has hereinabove been fully described, is adapted to operate in the same manner with the present embodiment through the link 27 and the piston rods 55 and 56 integrally positioned on the piston 50.

It will be apparent that a novel form of an electrical quantity regulation control means and system has been provided by this invention, which includes a compensating means immediately responsive to quantity variations, simultaneous to the reaction of an acutator member, which substantially eliminates objectionable hunting common to many regulating servo mechanisms.

I claim:

1. In an alternating current electrical system having adjustable control means to control the magnitude of an electrical quantity of said system; a hydraulic work cylinder including dual pressure chambers each having a piston slidable therein, condition responsive means responsive to variations in said electrical quantity and including a solenoid coil and magnetic plunger, said plunger comprising a temperature sensitive magnetic alloy having its magnetic permeability proportional to change in ambient temperature, a selective slide valve jointly associated with said working cylinder and with a source of hydraulic fluid under pressure to alternatively admit said fluid to said dual chambers, a cantilever actuator jointly operatively associated with said plunger and with said valve, said actuator being rotatively positioned on a shaft member and having a portion extending radially from said shaft member, a crank rotatable on said shaft member and operatively associated with said piston members, and a compensating member rotatable relative to said shaft member and frictionally engaged radially relative to said crank, opposed spring members each conjointly engaging said compensating member and the radially extending portion of said actuator, whereby movement of said magnetic plunger will simultaneously actuate said slide valve and said compensating member through the medium of said actuator and said opposed spring members to permit balanced movement of said pistons in a preselected direction alternatively responsive to variations in said electrical quantity.

2. In an alternating current electrical system having adjustable control means to control the magnitude of an electrical quantity of said system; a hydraulic work cylinder including a piston arranged for actuation of said control means, condition responsive means responsive to variations in said electrical quantity, a selective slide valve jointly associated with said Working cylinder and with a source of hydraulic fluid under pressure to selectively admit said fluid to said cylinder, an actuator jointly operatively associated with said condition responsive means and with said valve, and compensating means for providing balanced movement of said piston and comprising a pair of frictionally engaged relatively movable members, one of said movable members being connected to said piston, and force balancing means interconnecting the other of said relatively movable members and said actuator, whereby movement of said condition responsive means will simultaneously actuate said slide valve and said other of said relatively movable members through the medium of said actuator and said force balancing means to permit balanced movement of said piston in a preselected direction alternatively responsive to variations in said electrical quantity.

3. In an alternating current electrical system having adjustable control means to control the magnitude of an electrical quantity of said system; a hydraulic work cylinder including a piston arranged for actuation of said control means, condition responsive means responsive to variations in said electrical quantity, a selective slide valve jointly associated with said working cylinder and with a source of hydraulic fluid under pressure to se lectively admit said fluid to said cylinder, an actuator jointly operatively associated with said condition responsive means and with said valve, and compensating means for providing balanced movement of said piston and comprising a shaft member, a crank rotatable upon said shaft member and operatively connected to said piston, a compensating member positioned on and rotatable relative to said shaft member, said compensating member and said crank being frictionally engaged radially relative to one another, and force balancing means interconnecting said compensating member and said actuator, whereby movement of said condition responsive means will simultaneously actuate said slide valve and said compensating member through the medium of said actuator and said force balancing means to permit balanced movement of said piston in a preselected direction alternatively responsive to variations in said electrical quantity.

4. In an alternating current electrical system having adjustable control means to control the magnitude of an electrical quantity of said system; a hydraulic work cylinder including a piston arranged for actuation of said control means, condition responsive means responsive to variations in said electrical quantity, selective valve means jointly associated with said working cylinder and with a source of hydraulic fluid under pressure to selectively admit said fluid to said cylinder, an actuator jointly operatively associated with said condition responsive means and with said valve means, and compensating means for providing balanced movement of said piston and comprising a shaft member, a crank rotatable upon said shaft member and operatively connected to said piston, a compensating member positioned on and rotatable relative to said shaft member, said compensating member and said crank being frictionally engaged radially relative to one another, and force balancing means interconnecting said compensating member and said actuator, whereby movement of said condition responsive means will simultaneously actuate said valve means and said compensating member through the medium of said actuator and said force balancing means to permit balanced movement of said piston in a preselected direction alternatively responsive to variations in said electrical quantity.

5. In an alternating current electrical system having adjustable control means to control the magnitude of an electrical quantity of said system; a hydraulic work cylinder including a piston arranged for actuation of said control means, condition responsive means responsive to variations in said electrical quantity, a selective slide valve jointly associated with said working cylinder and with a source of hydraulic fluid under pressure to selectively admit said fluid to said cylinder, an actuator jointly operatively associated with said condition responsive means and with said valve, and compensating means for providing balanced movement of said piston and comprising a shaft member, a crank rotatable upon said shaft member and operatively connected to said piston, a compensating member positioned on and rotatable relative to said shaft member, said compensating member and said crank being frictionally engaged radially relative to one another, and balanced resilient means interconnecting said compensating member and said actuator, whereby movement of said condition responsive means will simultaneously actuate said slide valve and said compensating member through the medium of said actuator and said balanced resilient means to permit balanced movement of said piston in a preselected direction alternatively responsive to variations in said electrical quantity.

6. In an alternating current electrical system having adjustable control means to control the magnitude of an electrical quantity of said system; a hydraulic work cylinder including dual pressure chambers, each having a piston slidable therein and each piston arranged for alternative actuation of said control means, condition responsive means responsive to variations in said electrical quantity, a selective slide valve jointly associated with said Working cylinder and with a source of hydraulic fluid under pressure to alternatively admit said fluid to said dual chambers, a cantilever actuator jointly operatively associated with said condition responsive means and with said valve, said actuator being rotatively positioned on a shaft member and having a portion extending radially from said shaft member, a crank rotatable on said shaft member and operatively associated with said piston members, and a compensating member rotatable relative to said shaft member and frictionally engaged radially relative to said crank, balanced resilient means conjointly engaging said compensating member and the radially extending portion of said actuator, whereby movement of said condition responsive means will simultaneously actuate said slide valve and said compensating member through the medium of said actuator and said resilient means to permit balanced movement of said pistons in a preselected direction alternatively responsive to variations in said electrical quantity.

7. In an alternating current electrical system having adjustable control means to control the magnitude of an electrical quantity of said system; a hydraulic work cylinder including dual pressure chambers, each having a piston slidable therein and each piston arranged for alternative actuation of said control means, condition responsive means responsive to variations in said electrical quantity and including a solenoid coil and magnetic plunger, a selective slide valve jointly associated with said Working cylinder and with a source of hydraulic fluid under pressure to alternatively admit said fluid to said dual chambers, acantilever actuator jointly operatively associated with said plunger and with said valve, said actuator being rotatively positioned on a shaft member and having a portion extending radially from said shaft member, a crank rotatable on said shaft member and operatively associated with said piston members, and a compensating member rotatable relative to said shaft member and frictionally engaged radially relative to said crank, opposed spring members each conjointly engaging said compensating member and the radially extending portion of said actuator, whereby movement of said magnetic plunger will simultaneously actuate said slide valve and said compensating member through the medium of said actuator and said opposed spring members to permit balanced movement of said pistons in a preselected direction alternatively responsive to variations in said electrical quantity.

8. In a pressure fluid operated controlling device including a hydraulic work cylinder having a piston for actuating a member to be controlled, condition responsive means, a selective slide valve jointly associated with said working cylinder and with a source of hydraulic fluid under pressure to selectively admit said fluid to said cylinder, the combination therewith of an actuator jointly operatively associated with said condition responsive means and with said valve, and compensating means for providing balanced movement of said piston and comprising a pair of frictionally engaged relatively movable members, one of said movable members being connected to said piston, and force balancing means interconnecting the other of said relatively movable members and said actuator, whereby movement of said condition responsive means will simultaneously actuate said slide valve and said other of said relatively movable members through the medium of said actuator and said force balancing means to permit balanced movement of said piston in a preselected direction alternatively responsive to conditions affecting said condition responsive means.

9. In a pressure fluid operated controlling device including a hydraulic work cylinder having a piston for actuating a member to be controlled, condition respon sive means, a selective slide valve jointly associated with said working cylinder and with a source of hydraulic fluid under pressure to selectively admit said fluid to said cylinder, the combination therewith of an actuator jointly operatively associated with said condition responsive means and with said valve, and compensating means for providing balanced movement of said piston and comprising a shaft member, a crank rotatable upon said shaft member and operatively connected to said piston, a compensating member positioned on and rotatable relative to said shaft member, said compensating member and said crank being frictionally engaged radially relative to one another, and force balancing means interconnecting said compensating member and said actuator, whereby movement of said condition responsive means will simultaneously actuate said slide valve and said compensating member through the medium of said actuator and said' force balancing means to permit balanced movement of said piston in a preselected direction alternatively responsive to conditions aifecting said condition responsive means. l

10. In a pressure fluid operated controlling device including a hydraulic work cylinder having a piston for actuating a member to be controlled, condition responsive means, selective valve means jointly associated with said working cylinder and with a source of hydraulic fluid under pressure to selectively admit said fluid to said cylinder, the combination therewith of an actuator jointly operatively associated with said condition responsive means and with said valve means, and compensating means for providing balanced movement of saidpiston and comprising a shaft member, a crank rotatable upon said shaft member and operatively connected vto said piston, a compensating member positioned on and rotatable relative to said shaft member, said compensating member and said crank being frictioually engaged radially relativeto one another, and force balancing means interconnecting said compensating member and said actuator, whereby movement of said condition responsive means will simultaneously actuate said valve means and said compensating member through the medium of said actuator and said force balancing means to permit balanced movement of said piston in a preselected direction alternatively responsive to conditions affecting said condition responsive means.

11. In a pressure fluid operated controlling device including a hydraulic work cylinder having a piston for actuating a member to be controlled, condition responsive means, a selective slide valve jointly associated with said working cylinder and with a source of hydraulic fluid under pressure to selectively admit said fluid to said cylinder, the combination therewith of an actuator jointly operatively associated with said condition responsive means and with said valve, and compensating means for providing balanced movement of said piston and comprising a shaft member, a crank rotatable upon said shaft member and operatively connected to said piston, a compensating member being frictionally engaged radially relative to one another, and balanced resilient means interconnecting said compensating member and said actuator, whereby movement of said condition responsive means will simultaneously actuate said slide valve and said other of said compensating member through the medium of said actuator and said balanced resilient means to permit balanced movement of said piston in a preselected direction alternatively responsive to conditions aflecting said condition responsive means.

12. In a pressure fluid operated controlling device including a hydraulic work cylinder having dual pressure chambers, each having a piston slidable therein and each piston arranged for alternatively actuating a member to be controlled, condition responsive means, a selective slide valve jointly associated with said working cylinder and with a source of hydraulic fluid under pressure to alternatively admit said fluid to said dual chambers, the combination therewith of a cantilever actuator jointly operatively associated with said condition responsive means and with said valve, said actuator being rotatively positioned on a shaft member and having a portion extending radially from said shaft member, a crank rotatable on said shaft member and operatively associated with said piston members, and a compensating member rotatable relative to said shaft member and frictionally engaged radially relative to said crank, balanced resilient means conjointly engaging said compensating member and the radially extending portion of said actuator, whereby movement of said condition responsive means will simultaneously actuate said slide valve and said compensating member through the medium of said actuator and said balanced resilient means to permit balanced movement of said pistons in a preselected direction alternatively responsive to conditions aifecting said condition responsive means.

13. In a pressure fluid operated controlling device including a hydraulic work cylinder having dual pressure chambers, each having a piston slidable therein and each piston arranged for alternatively actuating a member to be controlled, condition responsive means including a solenoid coil and magnetic plunger, a selective slide valve jointly associated with said working cylinder and with a.

source of hydraulic fluid under pressure to alternatively admit said fluid to said dual chambers, the combination therewith of a cantilever actuator jointly operatively associated with said plunger and with said valve, said actuator being rotatively positioned on a shaft member and.

having a portion extending radially from said shaft memher, a crank rotatable on said shaft member and operatively associated with said piston members, and a compensating member rotatable relative to said shaft member and frictionally engaged radially relative to said crank, opposed spring members each conjointly engaging said compensating member and the radially extending portion of said actuator, whereby movement of said plunger will simultaneously actuate said slide valve and said compensating member through the medium of said actuator and said opposed spring members to permit balanced movement of said pistons in a preselected direction alternatively responsive to conditions affecting said condition responsive means.

References Cited in the file of this patent UNITED STATES PATENTS 875,463 Schmitthenner Dec. 31, 1907 0 Ziebolz Tiebel Polson et al. Lawrence Muzzey Meredith Beman Weinfurt Schultz FOREIGN PATENTS France Dec. 31, 1940 June 8, 1954 July 11, 1949

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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2955575 *Jan 20, 1958Oct 11, 1960Maurice M LightLubricant-immersed outdoor motor structure
US3059663 *Sep 21, 1956Oct 23, 1962Swiss Colony IncRapid response in-motion control device
US3074010 *Jun 17, 1959Jan 15, 1963Mc Graw Edison CoVoltage regulating apparatus
US3167703 *Jun 17, 1959Jan 26, 1965Mc Graw Edison CoSelf-regulating transformer
US3200713 *Mar 26, 1962Aug 17, 1965Philips CorpHydraulic servo-mechanism
US4201116 *Jul 11, 1977May 6, 1980The Cessna Aircraft CompanyElectro-hydraulic proportional control servo valve
US4387331 *May 28, 1981Jun 7, 1983Kolosov Ivan ACharge-discharge current stabilizer for storage batteries
US4540892 *Dec 20, 1983Sep 10, 1985Rca CorporationMultiple input voltage power controller
Classifications
U.S. Classification323/255, 361/140, 91/387, 310/15, 307/144, 307/130, 361/178
International ClassificationH01F29/00, G05F1/10, H01F7/06, H01F29/02, G05F1/147
Cooperative ClassificationH01F29/025, G05F1/147, H01F7/06
European ClassificationG05F1/147, H01F7/06, H01F29/02B