US4138728A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic tachometer with variable bandwidth differentiator
Assignee: International Business Machines Corp
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Filing: 1977-06-29
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Granted: 1979-02-06
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Expires: 1997-06-29
Abstract
Abstract An electronic tachometer, for use in a disk drive system, to sense velocity of an accessing head mechanism relative to data tracks being accessed, comprises a first feedback loop comprising a variable bandwidth differentiator for receiving a position signal and providing a velocity signal; and a second feedback loop including the differentiator and means for supplying a control voltage to said differentiator in response to a variable velocity signal provided by the differentiator.
Inventors
- 👤 Joseph S. Tung
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:24
CPC Classifications
G; G11; G11B; G11B19/00; G11B19/20; G11B19/24; G01; G01P; G01P3/00; G01P3/42; G01P3/44
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
97 words
An electronic tachometer for sensing position and velocity of a movable device comprising: a variable gain amplifier; means for applying a position signal to said gain amplifier; a first feedback loop comprising said gain amplifier, and an integrating means coupled to said gain amplifier for providing a velocity signal indicating the velocity of said device; a second feedback loop comprising said gain amplifier, means for providing a control signal to said gain amplifier, said control signal varying with relation to variations of said velocity signal, and switching means for energizing said means for providing a control signal.
Claim 2
Dependent Claim
97 words
An electronic tachometer for sensing position and velocity of a movable device comprising: a variable gain amplifier; means for applying a position signal to said gain amplifier; a first feedback loop comprising said gain amplifier, and an integrating means coupled to said gain amplifier for providing a velocity signal indicating the velocity of said device; a second feedback loop comprising said gain amplifier, means for providing a control signal to said gain amplifier, said control signal varying with relation to variations of said velocity signal, and switching means for energizing said means for providing a control signal.
Claim 3
Dependent Claim
17 words
An electronic tachometer as in claim 1, wherein said variable gain amplifier is a two quadrant multiplier.
Claim 4
Dependent Claim
21 words
An electronic tachometer as in claim 1, wherein said integrating means comprises an resistine-capacitine network connected in said first feedback loop.
Claim 5
Dependent Claim
28 words
An electronic tachometer as in claim 1, wherein said control signal providing means comprises an analog summer, and a signal processor coupled to the output of said summer.
Claim 6
Dependent Claim
40 words
An electronic tachometer as in claim 4, including low pass filter channels coupled to the means for applying a position signal; said switching means being responsive to said low pass filter channels for controlling the signals applied to said summer.
Claim 7
Dependent Claim
20 words
An electronic tachometer as in claim 4, including means for applying a fixed reference signal to said variable gain amplifier.
Claim 8
Dependent Claim
36 words
An electronic tachometer as in claim 6, including a diode network coupled to the output of said signal processor for selectively controlling the application of said control signal and said reference voltage to said gain amplifier.
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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) | 1982-02-05 | 1982-08-07 | 1983-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-05 | 1986-08-07 | 1987-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-05 | 1990-08-07 | 1991-02-06 | $7700.00 | Window Closed / Lapsed |