Magnetic flux measuring apparatus by hysteresis characteristic type digital FLL using counter system for squid
US7248044B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 1, 2006 |
| Grant date | Jul 24, 2007 |
| Priority date | — |
| Expiry date | Dec 1, 2026 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S505/846
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In a SQUID magnetometer, high resolution, a high slew rate, and a high dynamic range are achieved without using expensive circuit components having a large number of processing bits and enabling a high speed processing operation. A digital FLL circuit using a double counter system is provided. This circuit utilizes two or more counters, for example, a change range counter in a digital FLL for carrying out a processing operation at a high speed and a reproducing counter in a control/measuring computer. In addition, in the present invention, hysteresis characteristics having a 1Φ0 positive margin is used. That is, a change of a state of a magnetic flux is counted by means of a counter. At the time of this change, control is made so as to track a different channel between cases in which a magnetic flux increases and decreases, thereby stabilizing the control.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.