Patent US4638223A successfully refreshed from Google Patents.
US4638223A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Motor driving circuit
Assignee: Sony Corp
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Filing: 1985-05-28
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Granted: 1987-01-20
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Expires: 2005-05-28
Abstract
Abstract A voltage has a level which depends on rotational speed of a motor. The voltage is applied to the motor to energize the motor. A current through the motor is sensed. The level of the voltage is adjusted in accordance with the sensed current.
Inventors
- 👤 Shigeru Tajima
- 👤 Toshiya Nakabayashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:46
CPC Classifications
H; H02; H02P; H02P6/00; H02P6/08; H02P6/10
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
98 words
A driving circuit for a motor, comprising: (a) means for generating a control signal which depends on rotation of the motor; (b) a PWM circuit outputting pulses which depend on the control signal; (c) means for generating a voltage which depends on the pulses from the PWM circuit; (d) means for applying the voltage to the motor; (e) means for sensing a current through the motor; (f) means for controlling the PWM circuit on the basis of the sensed current and the control signal; and (g) means for cutting off dc and low-frequency components of the sensed current.
Claim 2
Dependent Claim
98 words
A driving circuit for a motor, comprising: (a) means for generating a control signal which depends on rotation of the motor; (b) a PWM circuit outputting pulses which depend on the control signal; (c) means for generating a voltage which depends on the pulses from the PWM circuit; (d) means for applying the voltage to the motor; (e) means for sensing a current through the motor; (f) means for controlling the PWM circuit on the basis of the sensed current and the control signal; and (g) means for cutting off dc and low-frequency components of the sensed current.
Claim 3
Dependent Claim
84 words
A driving circuit for a motor, comprising: (a) means for sensing rotational speed of the motor; (b) means for generating a voltage whose level depends on the sensed rotational speed of the motor; (c) means for applying the voltage to the motor to energize the motor; (d) means for sensing a current through the motor; (e) means for adjusting the level of the voltage in accordance with the sensed current, and (f) means for cutting off dc and low-frequency components of the sensed current.
Claim 4
Dependent Claim
84 words
A driving circuit for a motor, comprising: (a) means for sensing rotational speed of the motor; (b) means for generating a voltage whose level depends on the sensed rotational speed of the motor; (c) means for applying the voltage to the motor to energize the motor; (d) means for sensing a current through the motor; (e) means for adjusting the level of the voltage in accordance with the sensed current, and (f) means for cutting off dc and low-frequency components of the sensed current.
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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) | 1990-01-19 | 1990-07-21 | 1991-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-01-19 | 1994-07-21 | 1995-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-01-19 | 1998-07-21 | 1999-01-20 | $7700.00 | Window Closed / Lapsed |