US3887844A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Overcurrent protection circuit for a brushless direct current motor
Assignee: Pioneer Corp
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Filing: 1973-12-12
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Granted: 1975-06-03
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Expires: 1993-12-12
Abstract
Abstract Hall elements are used to control the energization of the driving coils of a brushless D.C. motor. An overcurrent in any one of the coils is detected by a resistor which produces a voltage which is delayed and then applied to a switching circuit which interrupts the control current of the Hall elements, thereby interrupting the driving coil current and stopping the motor.
Inventors
- 👤 Masayuki Yoshida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:53
CPC Classifications
H; H02; H02H; H02H7/00; H02H7/08; H02H7/0833
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
205 words
An overcurrent protection circuit for a brushless direct current motor including a rotor having at least one pair of magnetic poles and a stator including at least a pair of driving coils for rotating the rotor, said protection circuit comprising: a. driving circuit means for alternately supplying current to said driving coils; b. magneto-electric converting means for controlling said driving circuit by means of its output voltage, said output voltage varying in Accordance with the variation of the magnetic field generated by said magnetic poles of said rotor; c. a resistor connected in series with said driving coils and developing a voltage proportional to the current flowing through said coils; d. delay circuit means for delaying the voltage developed by said resistor; and e. switching circuit means, switched and latched when the output of said delay circuit increases to a predetermined level, for directly interrupting the operating control current of said magneto-electric converting means and for continuing the interruption even when the output of said delay circuit falls below said predetermined level, thereby turning OFF said converting means and interrupting the current flowing through said driving coils, said switching means being connected in series with the operating control current path for said magneto-electric converting means.
Claim 2
Dependent Claim
205 words
An overcurrent protection circuit for a brushless direct current motor including a rotor having at least one pair of magnetic poles and a stator including at least a pair of driving coils for rotating the rotor, said protection circuit comprising: a. driving circuit means for alternately supplying current to said driving coils; b. magneto-electric converting means for controlling said driving circuit by means of its output voltage, said output voltage varying in Accordance with the variation of the magnetic field generated by said magnetic poles of said rotor; c. a resistor connected in series with said driving coils and developing a voltage proportional to the current flowing through said coils; d. delay circuit means for delaying the voltage developed by said resistor; and e. switching circuit means, switched and latched when the output of said delay circuit increases to a predetermined level, for directly interrupting the operating control current of said magneto-electric converting means and for continuing the interruption even when the output of said delay circuit falls below said predetermined level, thereby turning OFF said converting means and interrupting the current flowing through said driving coils, said switching means being connected in series with the operating control current path for said magneto-electric converting means.
Claim 3
Dependent Claim
205 words
An overcurrent protection circuit for a brushless direct current motor including a rotor having at least one pair of magnetic poles and a stator including at least a pair of driving coils for rotating the rotor, said protection circuit comprising: a. driving circuit means for alternately supplying current to said driving coils; b. magneto-electric converting means for controlling said driving circuit by means of its output voltage, said output voltage varying in Accordance with the variation of the magnetic field generated by said magnetic poles of said rotor; c. a resistor connected in series with said driving coils and developing a voltage proportional to the current flowing through said coils; d. delay circuit means for delaying the voltage developed by said resistor; and e. switching circuit means, switched and latched when the output of said delay circuit increases to a predetermined level, for directly interrupting the operating control current of said magneto-electric converting means and for continuing the interruption even when the output of said delay circuit falls below said predetermined level, thereby turning OFF said converting means and interrupting the current flowing through said driving coils, said switching means being connected in series with the operating control current path for said magneto-electric converting means.
Claim 4
Dependent Claim
205 words
An overcurrent protection circuit for a brushless direct current motor including a rotor having at least one pair of magnetic poles and a stator including at least a pair of driving coils for rotating the rotor, said protection circuit comprising: a. driving circuit means for alternately supplying current to said driving coils; b. magneto-electric converting means for controlling said driving circuit by means of its output voltage, said output voltage varying in Accordance with the variation of the magnetic field generated by said magnetic poles of said rotor; c. a resistor connected in series with said driving coils and developing a voltage proportional to the current flowing through said coils; d. delay circuit means for delaying the voltage developed by said resistor; and e. switching circuit means, switched and latched when the output of said delay circuit increases to a predetermined level, for directly interrupting the operating control current of said magneto-electric converting means and for continuing the interruption even when the output of said delay circuit falls below said predetermined level, thereby turning OFF said converting means and interrupting the current flowing through said driving coils, said switching means being connected in series with the operating control current path for said magneto-electric converting means.
Claim 5
Dependent Claim
42 words
An overcurrent protection circuit as defined in claim 1 wherein said magneto-electric converting means comprises Hall element means for controlling the current supplied to said driving coils, switching circuit means is connected in series with the operating control current path for said.
References Cited (Backward Citations)
US3757185A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |