US4449095A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process and apparatus for recording hysteresis curves of magnetic materials
Assignee: Individual
•
Filing: 1981-07-20
•
Granted: 1984-05-15
•
Expires: 2001-07-20
Abstract
Abstract A process for measuring the hysteresis curve of magnetic materials comprises the generation of a magnetic field of varying amplitude, placing the sample to be measured into that field with a measuring coil and a potential coil attached thereto, integrating the signals from those coils to provide simultaneous values of flux density B and internal field intensity H, recording and storing the B and H values and converting these values to digital units in a transient recorder in real time and then feeding these signals to an X-Y recorder, a printer or other display device at a slower rate of speed to provide a hysteresis curve, or a display of programmed values of magnetic characteristics of the sample being measured.
Inventors
- 👤 Erich Steingroever
- 👤 Dietrich Steingroever
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:39
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/12; G01R33/14
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
128 words
Process for measuring the hysteresis curve of a magnetic material comprising the steps of: subjecting a magnetic material for a period of time to an alternating magnetic field of decreasing amplitude generated by periodic discharge of a capacitor connected with a field coil; measuring the flux density B to which said magnetic material is subjected and the internal field intensity H of said material during said period of time; converting the values of B and H into digital units and recording said digital units of B and H separately and simultaneously in real time, and; retrieving from said stored units in the form of electrical signals at least one value of units for each of both B and H which were stored at a given instant in time.
Claim 2
Dependent Claim
128 words
Process for measuring the hysteresis curve of a magnetic material comprising the steps of: subjecting a magnetic material for a period of time to an alternating magnetic field of decreasing amplitude generated by periodic discharge of a capacitor connected with a field coil; measuring the flux density B to which said magnetic material is subjected and the internal field intensity H of said material during said period of time; converting the values of B and H into digital units and recording said digital units of B and H separately and simultaneously in real time, and; retrieving from said stored units in the form of electrical signals at least one value of units for each of both B and H which were stored at a given instant in time.
Claim 3
Dependent Claim
40 words
Process of claim 1, wherein said electrical signals for one instant of time are fed to a digital display to display a specific characteristic of the measured material, such as remanence B r or coercive field intensity H C .
Claim 4
Dependent Claim
36 words
Process of claim 1, wherein a succession of said signals are fed to an analog display device, such as an X-Y recorder to provide at least a portion of a hysteresis curve of the measured material.
Claim 5
Dependent Claim
21 words
Process of claim 1, wherein a succession of said signals are fed to a digital display device, such as a printer.
Claim 6
Dependent Claim
20 words
Process of any one of claims 1, 2 or 3, wherein the material being measured is a soft magnetic material.
Claim 7
Dependent Claim
27 words
Process of claim 5, which includes the step of subjecting the material to be measured to an alternating magnetic field having an adjustable curve shape and frequency.
Claim 8
Dependent Claim
20 words
Process of any one of claims 1, 2 or 3, wherein the material being measured is a hard magnetic material.
Claim 9
Dependent Claim
57 words
Process of any one of claims 1, 2 or 3, which includes the steps of subjecting the material to be measured to a magnetic field having a first polarity and an amplitude sufficient to saturate said material and a second amplitude of reversed polarity greater than the coercive field intensity J H C of the measured material.
Claim 10
Dependent Claim
38 words
Process of any one of claims 1, 2 or 3 which includes the step of subjecting the material to be measured to an alternating magnetic field having a frequency insufficient to create eddy current that could distort measurements.
Claim 11
Dependent Claim
37 words
Process of any one of claims 1, 2 or 3, wherein electrical values of said flux density B and internal field intensity H are obtained by means of sensing instruments mounted on the material to be measured.
Claim 12
Dependent Claim
158 words
Apparatus for measuring the hysteresis curve of a magnetic material, comprising: means to generate an alternating magnetic field of short duration having a high initial amplitude with a decreasing amplitude thereafter within which field a sample to be measured may be placed; measuring coil means and potential coil means, both to be attached to said sample; integrating means connected with said measuring coil means and potential coil means for converting electrical values detected by said coils into respective electrical signals indicating values of flux density B and internal field intensity H of said sample while in said magnetic field; transient recorder means having at least two channels connected to said integrating means for recording and storing said values of B and H in real time, and for converting said values into digital units; and display means connected to the output of said transient recorder means for displaying at least one set of simultaneous values of B and H.
Claim 13
Dependent Claim
158 words
Apparatus for measuring the hysteresis curve of a magnetic material, comprising: means to generate an alternating magnetic field of short duration having a high initial amplitude with a decreasing amplitude thereafter within which field a sample to be measured may be placed; measuring coil means and potential coil means, both to be attached to said sample; integrating means connected with said measuring coil means and potential coil means for converting electrical values detected by said coils into respective electrical signals indicating values of flux density B and internal field intensity H of said sample while in said magnetic field; transient recorder means having at least two channels connected to said integrating means for recording and storing said values of B and H in real time, and for converting said values into digital units; and display means connected to the output of said transient recorder means for displaying at least one set of simultaneous values of B and H.
Claim 14
Dependent Claim
30 words
Apparatus defined in claim 11, wherein said display means is an X-Y recorder for recording at a lower speed at least a portion of the hysteresis curve of said sample.
Claim 15
Dependent Claim
34 words
Apparatus defined in claim 11, wherein said display means is a printer for recording simultaneous values of B and H, or programmed characteristics of said sample derived from said values of B and H.
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) | 1987-05-15 | 1987-11-14 | 1988-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-15 | 1991-11-14 | 1992-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-15 | 1995-11-14 | 1996-05-15 | $7700.00 | Window Closed / Lapsed |