Patent US5703449A successfully refreshed from Google Patents.
US5703449A
Expired / Lapsed
US
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Controller for brushless DC motor without position sensor
Assignee: Seiko Epson Corp
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Filing: 1996-03-14
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Granted: 1997-12-30
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Expires: 2016-03-14
Abstract
Abstract A controller according to one embodiment restarts the motor when a commutation timing signal is mismatched with an output pattern mode. A controller according to another embodiment compares the motor speed with the reference signal to change the chopper frequency in accordance with the compared value. A controller according to still another embodiment continuously changes the chopper frequency in accordance with the motor speed. A controller according to yet another embodiment inhibits the position detection immediately after commutation in accordance with the current flowing through the motor. A controller according to another embodiment detects the position of the rotor in accordance with the waveform of the current flowing through the motor.
Inventors
- 👤 Takashi Nagate
- 👤 Akihito Uetake
- 👤 Yoshikazu Koike
- 👤 Kunio Tabata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:00
CPC Classifications
H; H02; H02K; H02K1/00; H02K1/06; H02K1/22; H02K1/27; H02K1/2706; H02K1/272; H02K1/274; H02K1/2746; H02K29/00; H02K29/06; H02K29/12; H02P; H02P6/00; H02P6/14; H02P6/16; H02P6/18; H02P6/20; H02P6/21
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
180 words
A controller for a brushless DC motor without a position sensor including an inverter for driving the motor under chopper control and utilizing a counter electromotive force generated in stator coils of respective phases as a rotor is rotated in order to detect a position of the rotor and thereby to generate a commutation signal, said controller comprising a mode detector connected to the inverter for detecting a commutation timing signal detector connected to said mode detector to generate a commutation timing signal, an output pattern mode generator connected to said commutation timing signal detector to generate output patterns of several types with which said stator coils are excited, a pattern coincidence detector connected to said commutation timing signal detector and said output pattern mode generator to detect a coincidence that signals output from said commutation timing signal detector and said output pattern mode generator match each other and a starting controller connected to said pattern coincidence detector to stop a motor drive output once when no coincidence is detected by said pattern coincidence detector and to cause a restarting.
Claim 2
Dependent Claim
180 words
A controller for a brushless DC motor without a position sensor including an inverter for driving the motor under chopper control and utilizing a counter electromotive force generated in stator coils of respective phases as a rotor is rotated in order to detect a position of the rotor and thereby to generate a commutation signal, said controller comprising a mode detector connected to the inverter for detecting a commutation timing signal detector connected to said mode detector to generate a commutation timing signal, an output pattern mode generator connected to said commutation timing signal detector to generate output patterns of several types with which said stator coils are excited, a pattern coincidence detector connected to said commutation timing signal detector and said output pattern mode generator to detect a coincidence that signals output from said commutation timing signal detector and said output pattern mode generator match each other and a starting controller connected to said pattern coincidence detector to stop a motor drive output once when no coincidence is detected by said pattern coincidence detector and to cause a restarting.
Claim 3
Dependent Claim
51 words
A controller according to claim 1, wherein said pattern coincidence detector comprises an EX-OR gate connected to said output pattern mode generator and said commutation timing signal detector and a NAND gate connected to said EX-OR gate and said commutation timing signal detector to output a signal to said starting controller.
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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) | 2000-12-29 | 2001-06-30 | 2001-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-12-29 | 2005-06-30 | 2005-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-12-29 | 2009-06-30 | 2009-12-30 | $7700.00 | Window Closed / Lapsed |