US3667019A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control circuit for adjusting and regulating the speed of a brushless direct current motor responsive to voltages induced in the armature windings
Assignee: Motors Liquidation Co
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Filing: 1970-10-12
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Granted: 1972-05-30
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Expires: 1990-10-12
Abstract
Abstract A control circuit for adjusting and regulating the speed of a brushless direct current motor having three ''''wye'''' connected armature coils, a permanent magnet field and a rotatable shaft. Each motor armature coil is connected in series with the collector-emitter electrodes of a respective switching transistor across a source of direct current supply potential, the baseemitter electrodes of each switching transistor being connected across the source of direct current supply potential through a respective photosensitive electrical switching device and the collector-emitter electrodes of a control transistor. A selectively variable magnitude of a direct current control potential is applied across the base-emitter electrodes of the control transistor and the photosensitive electrical switching devices are sequentially illuminated as the shaft rotates to sequentially establish the switching transistor base-emitter drive circuits. A direct current regulating potential generated in the motor armature coils as they are ''''cut'''' by the flux produced by the permanent magnet field is of a magnitude proportional to the speed of the motor and is applied in a reverse polarity relationship to the control potential for regulating the speed of the motor.
Inventors
- 👤 James O Elliott
- 👤 George W Jackson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:33
CPC Classifications
H; H02; H02K; H02K29/00; H02K29/06; H02K29/10; H02P; H02P6/00; H02P6/06
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
265 words
A control circuit for adjusting and regulating the speed of a brushless direct current motor having three ''''wye'''' connected armature coils, a permanent magnet field and a rotatable shaft comprising a combination with a source of direct current supply potential, first, second and third switching transistors and a control transistor each having a control electrode and two current carrying electrodes, means for connecting said current carrying electrodes of each one of said switching transistors in series with a respective one of said motor armature coils across said source of direct current supply potential for establishing and interrupting an energizing circuit for each respective motor armature coil, first, second and third photosensitive electrical switching devices, means for connecting said control electrode and a selected one of said current carrying electrodes of each one of said switching transistors, a respective one of said photoelectrical switching devices and said current carrying electrodes of said control transistor across said source of direct current supply potential, means for producing a direct current control potential, means for applying selectively variable magnitudes of said control potential across said control electrode and a selected one of said current carrying electrodes of said control transistor for selectively varying the speed of said motor, means for sequentially illuminating and shading said photosensitive electrical switching devices as said rotatable shaft rotates for sequentially establishing and interrupting said energizing circuits of said motor armature coils, means for producing a regulating potential of a magnitude proportional to the speed of said motor, and means for applying said regulating potential to said control potential in an opposite polarity relationship.
Claim 2
Dependent Claim
265 words
A control circuit for adjusting and regulating the speed of a brushless direct current motor having three ''''wye'''' connected armature coils, a permanent magnet field and a rotatable shaft comprising a combination with a source of direct current supply potential, first, second and third switching transistors and a control transistor each having a control electrode and two current carrying electrodes, means for connecting said current carrying electrodes of each one of said switching transistors in series with a respective one of said motor armature coils across said source of direct current supply potential for establishing and interrupting an energizing circuit for each respective motor armature coil, first, second and third photosensitive electrical switching devices, means for connecting said control electrode and a selected one of said current carrying electrodes of each one of said switching transistors, a respective one of said photoelectrical switching devices and said current carrying electrodes of said control transistor across said source of direct current supply potential, means for producing a direct current control potential, means for applying selectively variable magnitudes of said control potential across said control electrode and a selected one of said current carrying electrodes of said control transistor for selectively varying the speed of said motor, means for sequentially illuminating and shading said photosensitive electrical switching devices as said rotatable shaft rotates for sequentially establishing and interrupting said energizing circuits of said motor armature coils, means for producing a regulating potential of a magnitude proportional to the speed of said motor, and means for applying said regulating potential to said control potential in an opposite polarity relationship.
Claim 3
Dependent Claim
235 words
A speed control circuit for adjusting and regulating the speed of a brushless direct current motor having three ''''wye'''' connected armature coils, a permanent magnet field and a rotatable shaft comprising in combination with a source of direct current supply potential, first, second and third switching transistors and a control transistor each having base, emitter and collector electrodes, means for connecting said collector-emitter electrodes of each one of said switching transistors in series with a respective one of said motor armature coils across said source of direct current supply potential for establishing and interrupting an energizing circuit for each respective motor armature coil, first, second and third photosensitive electrical switching devices, means for connecting said emitter-base electrodes of each one of said switching transistors, a respective one of said photoelectrical switching devices and said collector-emitter electrodes of said control transistor across said source of direct current supply potential, means for producing a direct current control potential, means for applying selectively variable magnitudes of said control potential across said base-emitter electrodes of said control transistor, means for sequentially illuminating and shading said photosensitive electrical switching devices as said rotatable shaft rotates for sequentially establishing and interrupting said energizing circuits of said motor armature coils, means for producing a regulating potential of a magnitude proportional to the speed of said motor, and means for applying said regulating potential to said control potential in an opposite polarity relationship.
Claim 4
Dependent Claim
235 words
A speed control circuit for adjusting and regulating the speed of a brushless direct current motor having three ''''wye'''' connected armature coils, a permanent magnet field and a rotatable shaft comprising in combination with a source of direct current supply potential, first, second and third switching transistors and a control transistor each having base, emitter and collector electrodes, means for connecting said collector-emitter electrodes of each one of said switching transistors in series with a respective one of said motor armature coils across said source of direct current supply potential for establishing and interrupting an energizing circuit for each respective motor armature coil, first, second and third photosensitive electrical switching devices, means for connecting said emitter-base electrodes of each one of said switching transistors, a respective one of said photoelectrical switching devices and said collector-emitter electrodes of said control transistor across said source of direct current supply potential, means for producing a direct current control potential, means for applying selectively variable magnitudes of said control potential across said base-emitter electrodes of said control transistor, means for sequentially illuminating and shading said photosensitive electrical switching devices as said rotatable shaft rotates for sequentially establishing and interrupting said energizing circuits of said motor armature coils, means for producing a regulating potential of a magnitude proportional to the speed of said motor, and means for applying said regulating potential to said control potential in an opposite polarity relationship.
Claim 5
Dependent Claim
260 words
A speed control circuit for adjusting and regulating the speed of a brushless direct current motor having three ''''wye'''' connected armature coils, a permanent magnet field and a rotatable shaft comprising in combination with a source of direct current supply potential, first, second and third switching transistors and a control transistor each having a control electrode and two current carrying electrodes, means for connecting said current carrying electrodes of each one of said switching transistors in series with a respective one of said motor armature coils across said source of direct current supply potential, first, second and third photosensitive electrical switching devices, means for connecting said control electrode and a selected one of said current carrying electrodes of each one of said switching transistors, a respective one of said photoelectrical switching devices and said current carrying electrodes of said control transistor across said source of direct current supply potential, means for sequentially illuminating said photosensitive electrical switching devices as said rotatable shaft rotates, a potentiometer having a movable contact, a resistor, a Zener diode, means for connecting said potentiometer and said resistor in series across said source of direct current supply potential, means for connecting said control electrode of said control transistor to said movable contact of said potentiometer, means for connecting said Zener diode in shunt across said potentiometer, first, second and third diodes, and means for connecting the terminal end of each one of said motor armature coils through a respective one of said first, second and third diodes to the junction between said potentiometer and said resistor.
Claim 6
Dependent Claim
260 words
A speed control circuit for adjusting and regulating the speed of a brushless direct current motor having three ''''wye'''' connected armature coils, a permanent magnet field and a rotatable shaft comprising in combination with a source of direct current supply potential, first, second and third switching transistors and a control transistor each having a control electrode and two current carrying electrodes, means for connecting said current carrying electrodes of each one of said switching transistors in series with a respective one of said motor armature coils across said source of direct current supply potential, first, second and third photosensitive electrical switching devices, means for connecting said control electrode and a selected one of said current carrying electrodes of each one of said switching transistors, a respective one of said photoelectrical switching devices and said current carrying electrodes of said control transistor across said source of direct current supply potential, means for sequentially illuminating said photosensitive electrical switching devices as said rotatable shaft rotates, a potentiometer having a movable contact, a resistor, a Zener diode, means for connecting said potentiometer and said resistor in series across said source of direct current supply potential, means for connecting said control electrode of said control transistor to said movable contact of said potentiometer, means for connecting said Zener diode in shunt across said potentiometer, first, second and third diodes, and means for connecting the terminal end of each one of said motor armature coils through a respective one of said first, second and third diodes to the junction between said potentiometer and said resistor.
Claim 7
Dependent Claim
246 words
A speed control circuit for adjusting and regulating the speed of a brushless direct current motor having three ''''wye'''' connected armature coils, a permanent magnet field and a rotatable shaft comprising in combination with a source of direct current supply potential, first, second and third switching transistors and a control transistor each having base, emitter and collector electrodes, means for connecting said collector-emitter electrodes of each one of said switching transistors in series with a respective one of said motor armature coils across said source of direct current supply potential, first, second and third photosensitive electrical switching devices, means for connecting said emitter-base electrodes of each one of said switching transistors, a respective one of said photoelectrical switching devices and said collector-emitter electrodes of said control transistor across said source of direct current supply potential, means for sequentially illuminating said photosensitive electrical switching devices as said rotatable shaft rotates, a potentiometer having a movable contact, a resistor, a Zener diode, means for connecting said potentiometer and said resistor in Series across said source of direct current supply potential, means for connecting said base electrode of said control transistor to said movable contact of said potentiometer, means for connecting said Zener diode in shunt across said potentiometer, first, second and third diodes, and means for connecting the terminal end of each one of said motor armature coils through a respective one of said first, second and third diodes to the junction between said potentiometer and said resistor.
Claim 8
Dependent Claim
246 words
A speed control circuit for adjusting and regulating the speed of a brushless direct current motor having three ''''wye'''' connected armature coils, a permanent magnet field and a rotatable shaft comprising in combination with a source of direct current supply potential, first, second and third switching transistors and a control transistor each having base, emitter and collector electrodes, means for connecting said collector-emitter electrodes of each one of said switching transistors in series with a respective one of said motor armature coils across said source of direct current supply potential, first, second and third photosensitive electrical switching devices, means for connecting said emitter-base electrodes of each one of said switching transistors, a respective one of said photoelectrical switching devices and said collector-emitter electrodes of said control transistor across said source of direct current supply potential, means for sequentially illuminating said photosensitive electrical switching devices as said rotatable shaft rotates, a potentiometer having a movable contact, a resistor, a Zener diode, means for connecting said potentiometer and said resistor in Series across said source of direct current supply potential, means for connecting said base electrode of said control transistor to said movable contact of said potentiometer, means for connecting said Zener diode in shunt across said potentiometer, first, second and third diodes, and means for connecting the terminal end of each one of said motor armature coils through a respective one of said first, second and third diodes to the junction between said potentiometer and said resistor.
References Cited (Backward Citations)
US3386019A
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US3250971A
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US3274471A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-30 | 1975-11-29 | 1976-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-30 | 1979-11-29 | 1980-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-30 | 1983-11-29 | 1984-05-30 | $7700.00 | Window Closed / Lapsed |