US3757183A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Redundant speed control for brushless hall effect motor
Assignee: National Aeronautics and Space Administration
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Filing: 1972-03-30
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Granted: 1973-09-04
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Expires: 1992-03-30
Abstract
Abstract A speed control system for a brushless Hall effect device equipped direct current (D.C.) motor in which separate windings of the motor are powered by separate speed responsive power sources and in which a change in speed, upward or downward, because of the failure of a component of one of the power sources results in a corrective signal being generated in the other power source to supply an appropriate power level and polarity to one winding to cause the motor to be corrected in speed.
Inventors
- 👤 F Huntsville
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:02
CPC Classifications
H; H02; H02P; H02P6/00; H02P6/06
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
330 words
A motor control system for a Hall effect commutating motor having first and second stationary windings, a permanent magnet rotor, and first and second Hall effect devices responsive to said rotor for controlling current flow to said windings, comprising: first and second speed signal generating means, each comprising means responsive to the rotation of said rotor for generating a signal of a magnitude proportional to the speed of said motor; first and second comparator means, each comprising means responsive to the output of a discrete said speed generating means for generating an output of a first polarity upon receiving a said signal of smaller value than a selected reference value and of an opposite, or second, polarity when said signal is of greater value than said selected reference value; first and second failure sensitive coupling means, each interconnecting the output of a discrete said comparator means to a control input of a discrete said Hall effect device and comprising means responsive to a preselected said value of said last named output for reducing its level to substantially zero; first and second power supplies, said first power supply beinG responsive to a control output of said first Hall effect device for powering said first winding and said second power supply being responsive to a control output of said second Hall effect device for powering said second winding; whereby, said first speed signal generating means, said first failure sensitive coupling means, said first Hall effect device and said first power supply comprise a first control channel, and said second speed signal generating means, said second comparator means, said second failure sensitive coupling means, said second Hall effect device and said second power supply comprise a second control channel and in the event of a failure of one of said control channels to provide an output as indicated by a properly functioning said speed signal generating means, said other control channel will provide a corrective output to correct the speed of said rotor.
Claim 2
Dependent Claim
330 words
A motor control system for a Hall effect commutating motor having first and second stationary windings, a permanent magnet rotor, and first and second Hall effect devices responsive to said rotor for controlling current flow to said windings, comprising: first and second speed signal generating means, each comprising means responsive to the rotation of said rotor for generating a signal of a magnitude proportional to the speed of said motor; first and second comparator means, each comprising means responsive to the output of a discrete said speed generating means for generating an output of a first polarity upon receiving a said signal of smaller value than a selected reference value and of an opposite, or second, polarity when said signal is of greater value than said selected reference value; first and second failure sensitive coupling means, each interconnecting the output of a discrete said comparator means to a control input of a discrete said Hall effect device and comprising means responsive to a preselected said value of said last named output for reducing its level to substantially zero; first and second power supplies, said first power supply beinG responsive to a control output of said first Hall effect device for powering said first winding and said second power supply being responsive to a control output of said second Hall effect device for powering said second winding; whereby, said first speed signal generating means, said first failure sensitive coupling means, said first Hall effect device and said first power supply comprise a first control channel, and said second speed signal generating means, said second comparator means, said second failure sensitive coupling means, said second Hall effect device and said second power supply comprise a second control channel and in the event of a failure of one of said control channels to provide an output as indicated by a properly functioning said speed signal generating means, said other control channel will provide a corrective output to correct the speed of said rotor.
Claim 3
Dependent Claim
64 words
A motor control system as set forth in Claim 1 wherein a said failure sensitive coupling means comprises: a transistor switch connected across the control input of said Hall effect device; and voltage sensitive means responsive to said preselected value of said output from said comparator means for ''''triggering on'''' said transistor switch and substantially shorting the control input to said Hall effect device.
Claim 4
Dependent Claim
73 words
A motor control system as set forth in Claim 2 further comprising a gain setting circuit interconnecting each said comparator means to each said Hall effect device and comprising first and second impedance paths connected in parallel and wherein one of said impedance paths includes a rectifier whereby current flow between a said comparator means and said Hall effect device in one direction is substantially greater than current flow in the opposite direction.
Claim 5
Dependent Claim
52 words
A motor control system as set forth in Claim 3 wherein said impedance paths have a conductance to enable substantially identical current flow with an applied one half voltage of a said second, or ''''decrease speed'''' polarity compared with a first or ''''increase speed'''' polarity signal for ''''triggering on'''' said transistor switch.
Claim 6
Dependent Claim
65 words
A motor control system as set forth in Claim 2 further comprising a buffer circuit interconnecting each of said comparators to a said gain setting circuit, a said failure sensitive means and a said Hall effect device comprising an amplifier including a pair of complementary transistors, the base input terminals of which are connected together and the emitter output terminals of which are connected together.
Claim 7
Dependent Claim
68 words
A motor control system as set forth in Claim 5 wherein: each said speed signal generating means is an alternating current generator; and the system further comprises an input circuit interconnecting said speed signal generating means of a said comparator means comprises an adjustable resistor, a rectifier, and a smoothing filter; whereby a selectively attenuated direct current is provided as said input signal to a said comparator means.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-03 | 1977-03-05 | 1977-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-03 | 1981-03-05 | 1981-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-03 | 1985-03-05 | 1985-09-04 | $7700.00 | Window Closed / Lapsed |