Arbitrary drive for magnetic field waveform control
AssigneeTexas Instruments Incorporated
InventorRobert J. Whitinger
Life of this patent
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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.
Claims14
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.
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.
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.
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.
Dependencies are inferred from the claim text.