US3601676A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Balance circuit for dc servos
Assignee: Information Storage Systems Inc
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Filing: 1969-08-20
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Granted: 1971-08-24
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Expires: 1989-08-20
Abstract
Abstract A balance circuit for neutralizing offsets and drift of all inputs to the summing amplifier of a DC servo including: a balance amplifier for comparing the drive signal applied to a servo controlled motor with selected inputs to the summing amplifier to determine any difference therebetween and developing a balance signal for feedback to the input of the summing amplifier which is equal to, but out of phase with the difference, and circuitry for applying the balance signal during both the fine and coarse position steps of the servo operation.
Inventors
- 👤 Martin O Halfhill
- 👤 Frank J Sordello
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:11
CPC Classifications
G; G05; G05D; G05D3/00; G05D3/12; G05D3/14; G05D3/1436
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
89 words
A balance circuit for neutralizing offset and drift in a DC servo which includes a circuit means for producing a motor position signal from a plurality of inputs to control the coarse and fine positioning of a movable load, comprising: first means for developing a balance signal from the motor position signal during the fine positioning of the load; and second means connected to the first means for holding the balance signal and applying it to the circuit means during both the fine and coarse positioning of the load.
Claim 2
Dependent Claim
89 words
A balance circuit for neutralizing offset and drift in a DC servo which includes a circuit means for producing a motor position signal from a plurality of inputs to control the coarse and fine positioning of a movable load, comprising: first means for developing a balance signal from the motor position signal during the fine positioning of the load; and second means connected to the first means for holding the balance signal and applying it to the circuit means during both the fine and coarse positioning of the load.
Claim 3
Dependent Claim
30 words
A balance circuit as recited in claim 1 including: gating means for interrupting the connection between the first means and the second means during the coarse positioning of the load.
Claim 4
Dependent Claim
35 words
A balance circuit as defined in claim 1 including: filter means for limiting the bandwidth of the balance circuit so that the second means is responsive only to low frequencies of less than 60 c.p.s.
Claim 5
Dependent Claim
41 words
A balance circuit as defined in claim 1 wherein: the first means includes comparison means for determining the difference between the motor drive signal and the inputs to the circuit means that are significant to the fine positioning of the load.
Claim 6
Dependent Claim
28 words
A balance circuit as defined in claim 1 including: control means for applying an initial approximate balance signal to the circuit means where the servo is initially activated.
Claim 7
Dependent Claim
49 words
A balance circuit as defined in claim 5 wherein: the second means includes a plurality of impedances in series with a capacitor, and the control means includes means for bypassing the impedances to reduce the time constant of the capacitor dUring a predetermined period after activation of the servo.
Claim 8
Dependent Claim
26 words
A balance circuit as defined in claim 1 including: means for loading the balance signal in one direction so that the signal has a constant polarity.
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) | 1974-08-23 | 1975-02-22 | 1975-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-23 | 1979-02-22 | 1979-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-23 | 1983-02-22 | 1983-08-24 | $7700.00 | Window Closed / Lapsed |