US3775648A
Expired / Lapsed
US
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Brushless motor control
Assignee: Garrett Corp
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Filing: 1971-08-04
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Granted: 1973-11-27
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Expires: 1991-08-04
Abstract
Abstract A brushless DC motor control system is provided in which auxiliary sense windings within the stator portion of the motor derive reference signals in response to rotation of the rotor. The reference signals are shifted in phase by a predetermined amount and shaped to provide generally rectangular waveforms prior to having the true and complementary values thereof combined by logical gating circuitry so as to selectively gate a plurality of power amplifiers which are associated with and which energize different ones of the main motor or stator windings. In the particular embodiment disclosed the reference signals are delayed 90* so as to be in-phase with selected pairs of the main motor windings and thereby establish a correct sequence of logical gating for the power amplifiers when the motor is rotating in one direction. The reference signals as delayed 90* are out-of-phase with certain pairs of the main motor windings to prevent rotation of the motor in the opposite direction. A starting circuit provides acceleration of the motor in the desired direction from rest or from a stalled condition by providing artificial reference signals which are gated to the power amplifiers to provide energization of the main windings on a random basis.
Inventors
- 👤 E Brown
- 👤 D Carter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:33
CPC Classifications
H; H02; H02P; H02P6/00; H02P6/20
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
161 words
In a motor in which first and second elements are rotatable relative to one another and the first element includes a plurality of different winding means operative to interact with the second element to produce rotation when sequentially energized, an arrangement for sensing the rotational position of the second element relative to the first element to provide energization of the plural winding means in proper sequence comprising: means responsive to rotation of the second element relative to the first element for generating a plurality of alternating reference signal having a known phase relationship to the plural winding means; means responsive to the alternating reference signals for generating a plurality of corresponding signals having a different phase from the reference signals; means responsive to the corresponding signals for logically combining the corresponding signals to produce a plurality of gating signals; and means responsive to the gating signals for selectively energizing the plural winding means in a sequence determined by the gating signals.
Claim 2
Dependent Claim
161 words
In a motor in which first and second elements are rotatable relative to one another and the first element includes a plurality of different winding means operative to interact with the second element to produce rotation when sequentially energized, an arrangement for sensing the rotational position of the second element relative to the first element to provide energization of the plural winding means in proper sequence comprising: means responsive to rotation of the second element relative to the first element for generating a plurality of alternating reference signal having a known phase relationship to the plural winding means; means responsive to the alternating reference signals for generating a plurality of corresponding signals having a different phase from the reference signals; means responsive to the corresponding signals for logically combining the corresponding signals to produce a plurality of gating signals; and means responsive to the gating signals for selectively energizing the plural winding means in a sequence determined by the gating signals.
Claim 3
Dependent Claim
34 words
The invention defined in claim 1 above, wherein the means for generating a plurality of alternating reference signals includes a plurality of sense windings disposed within the first element and adjacent the second element.
Claim 4
Dependent Claim
29 words
The invention defined in claim 1 above, wherein the means for generating a plurality of alternating reference signals includes at least two of the plurality of different winding means.
Claim 5
Dependent Claim
37 words
The invention defined in claim 1 above, wherein the means for generating a plurality of corresponding signals comprises means for integrating the alternating reference signals and means for generating the complement of the integrated alternating reference signals.
Claim 6
Dependent Claim
46 words
The invention defined in claim 1 above, further including means responsive to the absence of relative rotation between the first and second elements for applying a signal of varying waveform to the means for generating a plurality of corresponding signals to initiate operation of the motor.
Claim 7
Dependent Claim
125 words
A brushless control Circuit for a motor having a stator including a plurality of main stator windings and a rotor disposed within and rotatable relative to the stator comprising: a plurality of sense windings mounted within the stator and operative to generate a plurality of reference signals in response to rotation of the rotor; means responsive to each of the reference signals for generating a pair of corresponding signals which are phase displaced by substantially equal amounts and in opposite pluralities from the reference signal; means responsive to the corresponding signals for logically combining the corresponding signals to produce a plurality of gating signals; and means responsive to the gating signals for energizing the main stator windings in a sequence determined by the gating signals.
Claim 8
Dependent Claim
125 words
A brushless control Circuit for a motor having a stator including a plurality of main stator windings and a rotor disposed within and rotatable relative to the stator comprising: a plurality of sense windings mounted within the stator and operative to generate a plurality of reference signals in response to rotation of the rotor; means responsive to each of the reference signals for generating a pair of corresponding signals which are phase displaced by substantially equal amounts and in opposite pluralities from the reference signal; means responsive to the corresponding signals for logically combining the corresponding signals to produce a plurality of gating signals; and means responsive to the gating signals for energizing the main stator windings in a sequence determined by the gating signals.
Claim 9
Dependent Claim
22 words
The invention defined in claim 6 above, further including means responsive to each of the corresponding signals for squaring the waveform thereof.
Claim 10
Dependent Claim
47 words
The invention defined in claim 6 above, wherein each of the means for generating a pair of corresponding signals includes means for shifting the phase of the reference signal by a selected amount and means responsive to the phase shifted reference signal for generating the complement thereof.
Claim 11
Dependent Claim
26 words
The invention defined in claim 6 above, wherein each pair of corresponding signals are displaced from the reference signal by + or - 90 electrical degrees.
Claim 12
Dependent Claim
35 words
The invention defined in claim 6 above, further including starting circuit means for applying an alternating signal to one of the means for generating a pair of corresponding signals whenever the rotor is at rest.
Claim 13
Dependent Claim
154 words
A brushless control circuit for a motor having a stator including a plurality of main stator windings and a rotor disposed within and rotatable relative to the stator comprising: a plurality of sense windings mounted within the stator and operative to generate a plurality of reference signals in response to rotation of the rotor; means responsive to each of the reference signals for shifting the phase of the reference signal by a fixed amount; means responsive to each of the phase shifted reference signals for logically combining the phase shifted reference signals to produce a plurality of gating signals, said means being operative to logically AND each of the phase shifted reference signals and the complement thereof with all other phase shifted reference signals and the complements thereof to produce the gating signals; and means responsive to the gating signals for energizing the main stator windings in a sequence determined by the gating signals.
Claim 14
Dependent Claim
154 words
A brushless control circuit for a motor having a stator including a plurality of main stator windings and a rotor disposed within and rotatable relative to the stator comprising: a plurality of sense windings mounted within the stator and operative to generate a plurality of reference signals in response to rotation of the rotor; means responsive to each of the reference signals for shifting the phase of the reference signal by a fixed amount; means responsive to each of the phase shifted reference signals for logically combining the phase shifted reference signals to produce a plurality of gating signals, said means being operative to logically AND each of the phase shifted reference signals and the complement thereof with all other phase shifted reference signals and the complements thereof to produce the gating signals; and means responsive to the gating signals for energizing the main stator windings in a sequence determined by the gating signals.
Claim 15
Dependent Claim
203 words
A brushless control circuit for a motor having a stator including four stator windings disposed at locations spaced approximately 90* around the stator and a rotor disposed within and rotatable relative to the stator comprising: a pair of sense windings, each of which is disposed within the stator and forming angles of approximately 45* with a different adjacent pair of the four stator windings, each of the sense windings being responsive to rotation of the stator to generate a reference signal of generally sinusoidal waveform; means responsive to the reference signals for shifting the phases thereof by a fixed amount to produce a pair of phase shifted reference signals X and Y; means responsive to the phase shifted reference signals X and Y for producing the complements X and Y thereof; means for logically combining each of the phase shifted reference signals and complements with each of the other phase shifted reference signals and complements to produce four different gating signals X . Y, X . Y, X . Y and X . Y; and means responsive to the gating signals for energizing each of the four stator windings in accordance with the value of a different one of the four gating signals.
Claim 16
Dependent Claim
203 words
A brushless control circuit for a motor having a stator including four stator windings disposed at locations spaced approximately 90* around the stator and a rotor disposed within and rotatable relative to the stator comprising: a pair of sense windings, each of which is disposed within the stator and forming angles of approximately 45* with a different adjacent pair of the four stator windings, each of the sense windings being responsive to rotation of the stator to generate a reference signal of generally sinusoidal waveform; means responsive to the reference signals for shifting the phases thereof by a fixed amount to produce a pair of phase shifted reference signals X and Y; means responsive to the phase shifted reference signals X and Y for producing the complements X and Y thereof; means for logically combining each of the phase shifted reference signals and complements with each of the other phase shifted reference signals and complements to produce four different gating signals X . Y, X . Y, X . Y and X . Y; and means responsive to the gating signals for energizing each of the four stator windings in accordance with the value of a different one of the four gating signals.
Claim 17
Dependent Claim
42 words
The invention defined in claim 12 above, wherein the phase shifting means comprises a pair of Phase shifting circuits, each of which is coupled to receive a different one of the reference signals and comprises an operational amplifier coupled as an integrator.
Claim 18
Dependent Claim
69 words
The invention defined in claim 13 above, further including a starting circuit in the form of a relaxation oscillator coupled to be turned on to provide a signal of ramp waveform to one of the pair of phase shifting circuits whenever the rotor is at rest and responsive to the other one of the pair of phase shifting circuits to turn off whenever the rotor reaches a predetermined speed.
Claim 19
Dependent Claim
52 words
The invention defined in claim 12 above, wherein the complement producing means comprises a pair of squaring circuits, each of which is responsive to a different one of the phase shifted reference signals to convert the sinusoidal waveform of the reference signal into a squarewave and produce the complement of the squarewave.
Claim 20
Dependent Claim
48 words
The invention defined in claim 15 above, wherein each of the squaring circuits comprises a pair of transistors coupled to alternately conduct in response to the associated phase shifted reference signal, the two different transistors respectively producing the squarewave of the phase shifted reference signal and its complement.
Claim 21
Dependent Claim
47 words
The invention defined in claim 16 above, wherein the logically combining means comprises four pairs of diodes, each pair of which is coupled between a power supply and different ones of the transistor pairs within the squaring circuits to produce one of the four different gating signals.
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) | 1976-11-26 | 1977-05-28 | 1977-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-26 | 1981-05-28 | 1981-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-26 | 1985-05-28 | 1985-11-27 | $7700.00 | Window Closed / Lapsed |