US3748552A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Motor control circuit for tape drive
Assignee: Storage Technology Corp
•
Filing: 1971-07-12
•
Granted: 1973-07-24
•
Expires: 1991-07-12
Abstract
Abstract In a computer tape drive system, a fluctuating motor drive voltage is compared with a regulated voltage at the input to an operational amplifier to generate a voltage at the amplifier output for charging the coupling capacitor of a single-shot multivibrator. The single-shot period is then utilized to establish a motor drive period during which the motor drive voltage is applied to the motor. Since the single-shot period is inversely related to the voltage at the amplifier output and therefore inversely related to the motor drive voltage, any fluctuation in motor drive voltage is compensated for by a corresponding inverse change in the motor drive period.
Inventors
- 👤 W Arthur
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:30
CPC Classifications
H; H02; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/285; H02P7/29
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
187 words
A magnetic head, a capstan for driving tape past said magnetic head, a capstan motor for driving said cApstan and a single-shot multivibrator having a quasi-stable state duration determining the period during which a reverse drive is applied to said capstan motor for deceleration, the improvement comprising means for changing the duration of said quasi-stable state inversely with changes in motor drive voltage comprising: a regulated power supply providing a substantially constant voltage; an unregulated power supply providing said motor drive voltage; and a voltage comparison means having a first input, a second input and an output, said unregulated power suppy being coupled to said first input so as to apply said motor drive voltage thereto and said regulated power supply being coupled to said second input so as to apply said substantially constant voltage thereto to generate a voltage at said output directly related to the difference between said drive voltage and said constant voltage, said output being coupled to said multivibrator for biasing in a manner so as to vary said quasi-stable state duration inversely with respect to the variations in said motor drive voltage.
Claim 2
Dependent Claim
187 words
A magnetic head, a capstan for driving tape past said magnetic head, a capstan motor for driving said cApstan and a single-shot multivibrator having a quasi-stable state duration determining the period during which a reverse drive is applied to said capstan motor for deceleration, the improvement comprising means for changing the duration of said quasi-stable state inversely with changes in motor drive voltage comprising: a regulated power supply providing a substantially constant voltage; an unregulated power supply providing said motor drive voltage; and a voltage comparison means having a first input, a second input and an output, said unregulated power suppy being coupled to said first input so as to apply said motor drive voltage thereto and said regulated power supply being coupled to said second input so as to apply said substantially constant voltage thereto to generate a voltage at said output directly related to the difference between said drive voltage and said constant voltage, said output being coupled to said multivibrator for biasing in a manner so as to vary said quasi-stable state duration inversely with respect to the variations in said motor drive voltage.
Claim 3
Dependent Claim
14 words
The system of claim 1 wherein said voltage comparison means comprises an operational amplifier.
Claim 4
Dependent Claim
38 words
The system of claim 2 further comprising a feedback capacitance means for said amplifier to roll-off the voltage gain of said amplifier thereby preventing noise on said motor drive voltage from appearing at the output of said amplifier.
Claim 5
Dependent Claim
41 words
The system of claim 3 wherein said output voltage of said amplifier is directly and substantially linearly related to said motor drive voltage and the duration of said quasi-stable state is inversely and substantially linearly related to said motor drive voltage.
Claim 6
Dependent Claim
31 words
The system of claim 4 further comprising a bias network connected between said amplifier and said regulated power supply to provide a zero off-set for said output voltage of said amplifier.
References Cited (Backward Citations)
US3500163A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-23 | 1977-01-22 | 1977-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-23 | 1981-01-22 | 1981-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-23 | 1985-01-22 | 1985-07-24 | $7700.00 | Window Closed / Lapsed |