Saturable core magnetometer with a parallel resonant circuit in which the W3 DC level changes with a change in an external magnetic field
US5287059A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 14, 1992 |
| Grant date | Feb 15, 1994 |
| Priority date | — |
| Expiry date | Jan 14, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/04
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A magnetism detecting apparatus of this invention includes a magnetic sensor (11) constituted by a ferromagnetic core (12) and a detection coil (13) wound around the core (12), a parallel resonance circuit (15) constituted by the detection coil (13) of the magnetic sensor (11) and a capacitance element (14) connected in parallel with the detection coil (13), an oscillation circuit (18), which is constituted by an amplifier (16) to which the parallel resonance circuit (15) and a resistor (17) are connected as a feedback circuit, and the parallel resonance circuit (15), and excites the core (12) to a saturation region by using an oscillation current, and a waveform change detecting circuit (22, 24) for detecting a change in waveform of an output signal from the oscillation circuit (18). That is, the core (12) is excited to the saturation region by the oscillation circuit (18) using the detection coil (13) of the magnetic sensor (11) as part of the parallel resonance circuit (15), and an external magnetic field (H) applied to the magnetic sensor (11) is detected on the basis of the amount of change in waveform of an output signal (a) from the oscillation circuit (18). As a result, the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.