US3727012A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Calibrating a carrier erase magnetic tape analog recording system
Assignee: Texaco Inc
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Filing: 1971-11-19
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Granted: 1973-04-10
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Expires: 1991-11-19
Abstract
Abstract Herein disclosed is a system for increasing the temperature range of magnetic tape analog recording systems by periodically interrupting analog signals being recorded and introducing fixed calibration current levels proportional to the analog voltage across the recording head.
Inventors
- 👤 P Cox
- 👤 A Richter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:25
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/02
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
296 words
A system for recording an analog signal, comprising means for receiving said analog signal, means for providing direct current calibration signals, first switching means connected to the calibration signal means for sequentially passing the calibration signals in a predetermined order for a predetermined time interval, said first switching means includes a plurality of relays each relay having a coil and receiving a different calibration signal and being controlled by a control signal applied to its coil, so as to pass the calibration signal during the presence of the control signal and to block the calibration signal during the absence of a control signal, means for recording a signal on a magnetic medium, second switching means connected to the analog signal receiving means, to the first switching means and to recording means for passing a received analog signal to the recording means for a second predetermined time interval and for blocking the received analog signal during the first predetermined time interval while passing the calibration signals, passed by the first switching means, to the recording means; and means connected to the first and second switching means for controlling the first and second switching means, the control means includes means for providing timing pulses, a counter connected to the timing pulse means and counting the timing pulses, means connected to the counter and to the first and second switching means for decoding the count in the counter to provide a plurality of outputs as the control signals, one output occurring during the second predetermined time interval and is applied to the second switching means while the other outputs are provided as the control signals which occur at different times during the first time interval and applied to the different coils of the relays in the first switching means.
Claim 2
Independent Claim
296 words
A system for recording an analog signal, comprising means for receiving said analog signal, means for providing direct current calibration signals, first switching means connected to the calibration signal means for sequentially passing the calibration signals in a predetermined order for a predetermined time interval, said first switching means includes a plurality of relays each relay having a coil and receiving a different calibration signal and being controlled by a control signal applied to its coil, so as to pass the calibration signal during the presence of the control signal and to block the calibration signal during the absence of a control signal, means for recording a signal on a magnetic medium, second switching means connected to the analog signal receiving means, to the first switching means and to recording means for passing a received analog signal to the recording means for a second predetermined time interval and for blocking the received analog signal during the first predetermined time interval while passing the calibration signals, passed by the first switching means, to the recording means; and means connected to the first and second switching means for controlling the first and second switching means, the control means includes means for providing timing pulses, a counter connected to the timing pulse means and counting the timing pulses, means connected to the counter and to the first and second switching means for decoding the count in the counter to provide a plurality of outputs as the control signals, one output occurring during the second predetermined time interval and is applied to the second switching means while the other outputs are provided as the control signals which occur at different times during the first time interval and applied to the different coils of the relays in the first switching means.
Claim 3
Dependent Claim
86 words
A system as described in claim 1 in which the first means includes a plurality of different valued resistors receiving a direct current voltage, a plurality of switching devices, each switching device being connected to the decoding means, to a different resistor and to the recording means and controlled by one of the outputs from the decoding means to pass a direct current voltage from the resistor to the recording means during a predetermined time period of the first predetermined time interval as a calibration signal.
References Cited (Backward Citations)
US3275757A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-09 | 1976-10-09 | 1977-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-09 | 1980-10-09 | 1981-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-09 | 1984-10-09 | 1985-04-10 | $7700.00 | Window Closed / Lapsed |