Patent US3581110A successfully refreshed from Google Patents.
US3581110A
Expired / Lapsed
US
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Apparatus for evaluating signals read from magnetic medium
Assignee: GTE Automatic Electric Laboratories Inc
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Filing: 1969-02-17
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Granted: 1971-05-25
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Expires: 1989-02-17
Abstract
Abstract A two-stage transistorized, magnetic drumhead readout amplifier including a positive signal limiter and a negative signal limiter, followed by an excursion detector arranged to pass only that portion of a signal that swings from the positive to the negative direction, and then only of a predetermined magnitude. The passed signal is shaped by a monostable multivibrator prior to application to suitable logic circuitry.
Inventors
- 👤 Richard J Belcastro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:30
CPC Classifications
H; H03; H03K; H03K5/00; H03K5/01; H03K5/08; H03K3/00; H03K3/02; H03K3/26; H03K3/28; H03K3/281; H03K3/284
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
124 words
An apparatus supplied with an operating potential source connected to ground and a positive potential terminal for the evaluation of read signals corresponding to data magnetically recorded and in which an amplifier circuit means for producing amplification of read signals includes: first limiting means operative to limit said amplified signal excursion in a first direction, second limiting means operative to limit said amplified signal excursion in a second direction, and an excursion detector operated to pass a read signal only of the magnitude determined by said first and second means, said excursion detector including pulse polarizing means adapted to pass only negative-going signals, and a monostable multivibrator operated in response to a passed read signal from said excursion detector to produce a shaped pulse.
Claim 2
Independent Claim
124 words
An apparatus supplied with an operating potential source connected to ground and a positive potential terminal for the evaluation of read signals corresponding to data magnetically recorded and in which an amplifier circuit means for producing amplification of read signals includes: first limiting means operative to limit said amplified signal excursion in a first direction, second limiting means operative to limit said amplified signal excursion in a second direction, and an excursion detector operated to pass a read signal only of the magnitude determined by said first and second means, said excursion detector including pulse polarizing means adapted to pass only negative-going signals, and a monostable multivibrator operated in response to a passed read signal from said excursion detector to produce a shaped pulse.
Claim 3
Dependent Claim
48 words
Apparatus according to claim 1, wherein said amplifier includes a final amplification stage comprising an NPN transistor and said excursion detector comprises: a capacitor and resistor in series connected from said transistor emitter to ground potential and a diode with its cathode connected to ground shunting said resistor.
Claim 4
Dependent Claim
62 words
Apparatus according to claim 2, wherein said first limiting means comprises: a first and a second resistor in series connected respectively from ground to the positive potential supply with their common terminals connected to the anode of a diode whose other terminal is connected to the base of said transistor and further having a capacitor connected from said diode anode to ground.
Claim 5
Dependent Claim
28 words
Apparatus according to claim 2, wherein said second limiting means comprises: a parallel resistor and capacitor connected from the collector of said transistor to the positive potential supply.
Claim 6
Dependent Claim
28 words
Apparatus according to claim 3, wherein said second limiting means comprises: a parallel resistor and capacitor connected from the collector of said transistor to the positive potential supply.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-24 | 1974-11-23 | 1975-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-24 | 1978-11-23 | 1979-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-24 | 1982-11-23 | 1983-05-25 | $7700.00 | Window Closed / Lapsed |