US4400809A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Arbitrary drive for magnetic field waveform control
Assignee: Texas Instruments Inc
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Filing: 1981-03-02
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Granted: 1983-08-23
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Expires: 2001-03-02
Abstract
Abstract Disclosed is a method and apparatus for digital implementation and closed loop feedback of magnetic field waveforms utilizing three channels of a four channel incrementally programmable voltage source to drive field coils in each of three spatial axes, respectively. A fourth channel is utilized for signal conditioning of an output signal from a magnetic bubble memory undergoing test by injecting inverted noise to maximize the signal-to-noise ratio.
Inventors
- 👤 Robert J. Whitinger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 10:54
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/28; G01R31/2832; G01R31/2834; G11; G11C; G11C19/00; G11C19/02; G11C19/08; G11C19/085; G11C29/00; G11C29/003
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
98 words
An apparatus for controlling magnetic fields in one or more spatial axes comprising: (a) means for inducing magnetic fields in one or more spatial axes; (b) means for controlling said induced magnetic fields utilizing a set of programmed increments in digital format; (c) means for sensing said induced magnetic fields; and (d) means connected to said means for controlling and to said means for sensing said induced magnetic fields for modifying said induced magnetic fields in a closed loop feedback system such that said sensed magnetic fields are made to more closely resemble said set of programmed increments.
Claim 2
Independent Claim
98 words
An apparatus for controlling magnetic fields in one or more spatial axes comprising: (a) means for inducing magnetic fields in one or more spatial axes; (b) means for controlling said induced magnetic fields utilizing a set of programmed increments in digital format; (c) means for sensing said induced magnetic fields; and (d) means connected to said means for controlling and to said means for sensing said induced magnetic fields for modifying said induced magnetic fields in a closed loop feedback system such that said sensed magnetic fields are made to more closely resemble said set of programmed increments.
Claim 3
Dependent Claim
47 words
An apparatus as in claim 1 wherein said means for controlling the induced magnetic fields is comprised of a programmable digital computer system utilizing three channels of a multiple channel network to control the magnetic field of each of the three spatial axes independently of the others.
Claim 4
Dependent Claim
55 words
An apparatus as in claim 2 wherein said means for controlling said induced magnetic field includes: (a) means for sampling each field coil current; (b) means for comparing said current to a programmed set of waveform values; and (c) means for modifying said sampled current to more closely resemble said programmed set of waveform values.
Claim 5
Dependent Claim
37 words
An apparatus as in claim 2 wherein said means for controlling said induced magnetic field is comprised of a software programmable analog-to-digital converter interconnected between a field coil current sensing device and said programmable digital computer system.
Claim 6
Independent Claim
108 words
A method for controlling magnetic fields in one or more spatial axes comprised of the steps of: (a) programming a desired current waveform into a digital computer; (b) converting said current waveform into an analog voltage waveform; (c) amplifying said analog voltage waveform and applying it across a field coil, said coil developing an induced magnetic field corresponding to the resultant analog current waveform; (d) sampling said analog current waveform incrementally; (e) comparing said samples with said programmed current waveform; and (f) adjusting said analog voltage waveform with respect to said comparing step for the purpose of causing said sampled waveform to more nearly approximate said programmed waveform.
Claim 7
Independent Claim
108 words
A method for controlling magnetic fields in one or more spatial axes comprised of the steps of: (a) programming a desired current waveform into a digital computer; (b) converting said current waveform into an analog voltage waveform; (c) amplifying said analog voltage waveform and applying it across a field coil, said coil developing an induced magnetic field corresponding to the resultant analog current waveform; (d) sampling said analog current waveform incrementally; (e) comparing said samples with said programmed current waveform; and (f) adjusting said analog voltage waveform with respect to said comparing step for the purpose of causing said sampled waveform to more nearly approximate said programmed waveform.
Claim 8
Dependent Claim
53 words
A method as in claim 5 including the step of operating a signal conditioning feedback circuit, said circuit operable to provide incremental sampling of an output signal from a magnetic bubble memory device undergoing test, for the purpose of detecting noise therein, and adding said noise in an inverted form to said signal.
Claim 9
Dependent Claim
72 words
A method as in claim 6 wherein the step of operating a signal conditioning feedback circuit is included the steps of: (a) sampling a signal from a magnetic bubble memory device undergoing test and detecting noise therein; (b) inverting said detected noise in an incremental format; and (c) adding said inverted noise to said signal at an adjustable rate for the purpose of increasing the signal to noise ratio in said signal.
Claim 10
Dependent Claim
48 words
A method as in claim 5 wherein said step of converting a programmed waveform into an analog voltage waveform is comprised of utilizing three channels of a multiple channel digital computer system to incrementally control the magnetic field of each of three spatial axes independently of the others.
Claim 11
Dependent Claim
49 words
A method as in claim 8 wherein the step of converting a programmed waveform includes the steps of: (a) sampling each field coil current; (b) comparing said current to the programmed current waveform value; and (c) modifying said sampled current to more closely resemble said programmed current waveform value.
Claim 12
Dependent Claim
38 words
A method as in claim 8 wherein the step of converting a programmed waveform includes the step of utilizing a software programmable analog-to-digital converter interconnected between a field coil current sensing device and said programmable digital computer system.
Claim 13
Dependent Claim
91 words
A magnetic bubble memory testing method comprising the steps of: (a) programming a desired waveform into a multichannel digital computer; (b) converting signals from said computer into analog waveforms; (c) amplifying said analog waveforms; (d) converting said analog waveforms into magnetic fields; (e) sensing said magnetic fields and providing feedback to said digital computer; (f) improving an output signal from a magnetic bubble memory undergoing test utilizing one channel of said multichannel digital computer; and (g) controlling the timing of the above steps with respect to the various channels and functions.
Claim 14
Dependent Claim
91 words
A magnetic bubble memory testing method comprising the steps of: (a) programming a desired waveform into a multichannel digital computer; (b) converting signals from said computer into analog waveforms; (c) amplifying said analog waveforms; (d) converting said analog waveforms into magnetic fields; (e) sensing said magnetic fields and providing feedback to said digital computer; (f) improving an output signal from a magnetic bubble memory undergoing test utilizing one channel of said multichannel digital computer; and (g) controlling the timing of the above steps with respect to the various channels and functions.
Claim 15
Dependent Claim
25 words
A method as in claim 11 further including the step of switching programmed current waveforms in one or more channels independently of the other channels.
Claim 16
Dependent Claim
104 words
A magnetic bubble memory testing apparatus comprising: (a) a multichannel digital computer; (b) means for converting a series of digital signals into analog waveforms; (c) means for amplifying said analog waveforms; (d) means for converting said waveforms into magnetic fields; (e) means for sensing said magnetic fields and providing feedback to said digital computer; (f) a magnetic bubble memory undergoing test in magnetic communication with said magnetic fields to produce an output signal; (g) means for improving said output signal from said magnetic bubble memory utilizing one channel of said multichannel digital computer; and (h) means for interconnection and timing control of said apparatus.
Claim 17
Dependent Claim
104 words
A magnetic bubble memory testing apparatus comprising: (a) a multichannel digital computer; (b) means for converting a series of digital signals into analog waveforms; (c) means for amplifying said analog waveforms; (d) means for converting said waveforms into magnetic fields; (e) means for sensing said magnetic fields and providing feedback to said digital computer; (f) a magnetic bubble memory undergoing test in magnetic communication with said magnetic fields to produce an output signal; (g) means for improving said output signal from said magnetic bubble memory utilizing one channel of said multichannel digital computer; and (h) means for interconnection and timing control of said apparatus.
Claim 18
Dependent Claim
28 words
Apparatus as in claim 13 further including means connected to said means for converting to provide a selected one of a plurality of series of digital signals thereto.
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) | 1986-08-22 | 1987-02-21 | 1987-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-22 | 1991-02-21 | 1991-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-22 | 1995-02-21 | 1995-08-23 | $7700.00 | Window Closed / Lapsed |