US3671835A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Motor speed control with droop compensation
Assignee: Boeing North American Inc
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Filing: 1970-07-09
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Granted: 1972-06-20
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Expires: 1990-07-09
Abstract
Abstract Compensating for droop in load-speed characteristic of a DC motor, an armature current signal, which is indicative of motor load, is amplified to control armature voltage. A negative feedback reduces amplification as armature voltage increases. An operational amplifier has an input related to armature current and a negative feedback responsive to armature voltage. A transistor in the feedback path varies the feedback impedance as a function of armature voltage.
Inventors
- 👤 Frederick Mcmenamy
- 👤 Louis A De More
- 👤 Ludwig E Del Mastro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:15
CPC Classifications
H; H02; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/285; H02P7/292; H02P7/293; Y; Y10; Y10S; Y10S388/00; Y10S388/90; Y10S388/902; Y10S388/907; Y10S388/91
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
129 words
An armature-current compensation circuit for a DC motor which exhibits an increasing droop in its motor-speed-versus-load curve as armature voltage decreases, comprising: an amplifier having input and output terminals, input means for applying a signal representative of amplitude of current in an armature path of the motor to the input terminal, feedback means connecting the input and output terminals, the feedback means comprising variable conductance means for conducting feedback current, the variable conductance means having a control terminal for controlling conductance of said feedback current, control means for applying a signal representative of the voltage across said armature to the control terminal, and regulating means connected to the output terminal of the amplifier and responsive to a signal from the output terminal for regulating voltage supplied to the armature.
Claim 2
Dependent Claim
129 words
An armature-current compensation circuit for a DC motor which exhibits an increasing droop in its motor-speed-versus-load curve as armature voltage decreases, comprising: an amplifier having input and output terminals, input means for applying a signal representative of amplitude of current in an armature path of the motor to the input terminal, feedback means connecting the input and output terminals, the feedback means comprising variable conductance means for conducting feedback current, the variable conductance means having a control terminal for controlling conductance of said feedback current, control means for applying a signal representative of the voltage across said armature to the control terminal, and regulating means connected to the output terminal of the amplifier and responsive to a signal from the output terminal for regulating voltage supplied to the armature.
Claim 3
Dependent Claim
59 words
A circuit according to claim 1 wherein the input means comprises a current sensor connected to the armature path for deriving a signal representative of the amplitude of current in the armature path, and an input network for scaling and smoothing the signal from the current sensor and for applying a smoothed and scaled signal to the input terminal.
Claim 4
Dependent Claim
41 words
The circuit according to claim 1 wherein the feedback means comprises a linear resistor directly connecting the input and output terminals, and a series circuit comprising the variable conductance means and a scaling potentiometer connected between the input and output terminals.
Claim 5
Dependent Claim
19 words
A circuit according to claim 1 wherein said variable conductance means comprises a transistor biased in its active region.
Claim 6
Independent Claim
122 words
A method of compensating for a droop in the motor-speed-versus-load characteristic of a DC motor comprising the steps of generating a first signal representative of the amplitude of current in an armature path of the motor, generating a second signal representative of the voltage across the armature of the motor, generating a third signal having an amplitude substantially directly proportional to the first signal and varying inversely with the second signal, and using said third signal to control the amount of power applied to the armature of the motor, wherein said third signal generating step comprises feeding the first signal to an amplifier, controlling amplifier feedback by the second signal, to thereby produce the third signal at an output of the amplifier.
Claim 7
Independent Claim
122 words
A method of compensating for a droop in the motor-speed-versus-load characteristic of a DC motor comprising the steps of generating a first signal representative of the amplitude of current in an armature path of the motor, generating a second signal representative of the voltage across the armature of the motor, generating a third signal having an amplitude substantially directly proportional to the first signal and varying inversely with the second signal, and using said third signal to control the amount of power applied to the armature of the motor, wherein said third signal generating step comprises feeding the first signal to an amplifier, controlling amplifier feedback by the second signal, to thereby produce the third signal at an output of the amplifier.
Claim 8
Dependent Claim
46 words
The method of claim 5 wherein the second signal generating step comprises measuring voltage across the armature, producing a bias signal, feeding the third signal through an impedance to an input of the amplifier, and reducing the impedance according to a magnitude of the bias signal.
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) | 1975-06-20 | 1975-12-20 | 1976-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-20 | 1979-12-20 | 1980-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-20 | 1983-12-20 | 1984-06-20 | $7700.00 | Window Closed / Lapsed |