US4341982A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Simultaneous independent control system for electric motors
Assignee: Power Systems Inc
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Filing: 1980-07-03
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Granted: 1982-07-27
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Expires: 2000-07-03
Abstract
Abstract A system for simultaneously and independently controlling a plurality of electric motors from a number of dispersed stations. The system operates by transmission of duty cycle modulated selected frequencies superimposed on a DC track voltage on a common power line servicing the motors. The modulation is variable and determines the speed of the motors. Transmitters are portable and designed removably to plug into a common signal transmission cable anywhere along its length without interaction. Receivers, each tuned to a specific frequency and associated with and controlling a motor, are coupled to the common power line.
Inventors
- 👤 Abbott W. Lahti
- 👤 Stephen R. Russell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:27
CPC Classifications
A; A63; A63H; A63H19/00; A63H19/24
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
190 words
A system for simultaneously and independently controlling a plurality of motors comprising: (a) A common power line; (b) a plurality of motors connected to said power line; (c) a power supply unit comprising a wide bandwidth feedback regulated amplifier and power supply for generating low voltage propulsion power for said motors to said power line; (d) a common signal transmission cable coupled to the negative inverting input of said wide bandwidth feedback regulated amplifier and power supply; (e) a plurality of means for generating a plurality of modulated selected frequencies and for superimposing said frequencies via said power supply unit on said low voltage propulsion power, each of said means being portable and being removably parallel coupled to said common signal transmission cable; (f) a plurality of replaceable and interchangeable frequency selectors, one each for each one of said plurality of means for generating said plurality of modulated selected frequencies, for determining each of said selected frequencies; and (g) a plurality of receivers coupled to said common power line, each of said receivers tuned to one of said modulated selected frequencies and associated with and controlling one of said motors.
Claim 2
Independent Claim
190 words
A system for simultaneously and independently controlling a plurality of motors comprising: (a) A common power line; (b) a plurality of motors connected to said power line; (c) a power supply unit comprising a wide bandwidth feedback regulated amplifier and power supply for generating low voltage propulsion power for said motors to said power line; (d) a common signal transmission cable coupled to the negative inverting input of said wide bandwidth feedback regulated amplifier and power supply; (e) a plurality of means for generating a plurality of modulated selected frequencies and for superimposing said frequencies via said power supply unit on said low voltage propulsion power, each of said means being portable and being removably parallel coupled to said common signal transmission cable; (f) a plurality of replaceable and interchangeable frequency selectors, one each for each one of said plurality of means for generating said plurality of modulated selected frequencies, for determining each of said selected frequencies; and (g) a plurality of receivers coupled to said common power line, each of said receivers tuned to one of said modulated selected frequencies and associated with and controlling one of said motors.
Claim 3
Dependent Claim
17 words
The system of claim 1 wherein said common power line is a track for a model railroad.
Claim 4
Dependent Claim
11 words
The system of claim 1 wherein said motors are electric motors.
Claim 5
Dependent Claim
45 words
The system of claim 1 wherein said wide bandwidth feedback regulated amplifier and power supply is an operational amplifier having a reference voltage connected to its positive, non-inverting input and whose output is fed back across a resistive divider to its said negative inverting input.
Claim 6
Dependent Claim
77 words
The system of claim 1 wherein each of said plurality of means for generating a plurality of modulated selected frequencies includes a carrier signal generator for generating a carrier signal, a variable duty cycle modulator for modulating said carrier signal, and a plurality of progressively variable and individually selectable braking resistances working in opposition to and progressively against the position of said variable duty cycle modulator, whereby a multiplicity of deceleration rates for said motors is achievable.
Claim 7
Dependent Claim
40 words
The system of claim 5 wherein each of said pluraity of replaceable and interchangeable frequency selectors is a replaceable precision resistor, and said variable duty cycle modulator is a variable potentiometer that controls the speed of its said associated motor.
Claim 8
Dependent Claim
31 words
The system of claim 1 further characterized in that some of said plurality of means for generating said plurality of modulated selected frequencies are disposed remote from said power supply unit.
Claim 9
Dependent Claim
75 words
The system of claim 1 further characterized in that each of said receivers includes a pair of detectors, with each of said pair of detectors being a phase-locked loop detector, wherein one of said pair of detectors is tuned to a frequency f for driving its associated said motor in one direction and the other of said pair of detectors is tuned to an offsetting frequency f-Δf for driving said motor in the other direction.
Claim 10
Dependent Claim
29 words
The system of claim 8 wherein each of said receivers further includes an "H" bridge for driving its associated said motor under the control of said pair of detectors.
Claim 11
Dependent Claim
46 words
The system of claim 1 wherein said power supply unit further includes means for causing said power supply unit rapidly to cease the further generation of said propulsion power to said common power line in case of a short circuit or overload occurring in the system.
Claim 12
Dependent Claim
138 words
The system of claim 10 wherein said means is a high speed, latching electronic circuit breaker comprising a pair of transistors connected in a commonemitter configuration, with one of said pair of transitors being normally "on" and the other being normally "off", the base of the normally "off" transistor being coupled to the collector of the normally "on" transistor, wherein a short circuit or overload condition occurring in the system causes said normally "off" transistor to be turned "on" and said normally "on" transitor to be turned "off", causing also thereby to couple a signal from said collector of said normally "on" transistor to said base of said normally "off" transistor, which said signal latches said normally "off" transistor into its said conducting state even after said short circuit or said overload condition is removed from the system.
Claim 13
Dependent Claim
35 words
The system of claim 11 wherein said means is resettable by each of said plurality of means for generating said plurality of modulated selected frequencies which is parallel coupled to said common signal transmission cable.
Claim 14
Dependent Claim
34 words
The system of claim 1 wherein each of said plurality of receivers converts said respective modulated selected frequency to which it is tuned to a modulated propulsion power for driving its said associated motor.
Claim 15
Dependent Claim
16 words
The system of claim 1 wherein said plurality of modulated selected frequencies are duty cycle modulated.
Claim 16
Dependent Claim
14 words
The system of claim 13 wherein said modulated propulsion power is duty cycle modulated.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-07-26 | 1986-01-25 | 1986-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-07-26 | 1990-01-25 | 1990-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-07-26 | 1994-01-25 | 1994-07-27 | $7700.00 | Window Closed / Lapsed |