fluxgate

Motivation Recently, I began a project to build a (reasonably) accurate 3-axis magnetometer. One of the challenges in building a magnetometer is calibrating it with a known magnetic field. Creating a known magnetic field requires using a calibration coil with a known current flowing through it. If you want to make multiple (and consistent) measurements, it is very convenient to have the current under computer control…and that is where the Programmable Current Sink (PCS) got its’ start.

The ionosphere and geophysics have always been “hobbies” of mine. Recently, I began a project to build a 3-axis magnetometer. The first iteration of this project uses FG-3+ fluxgate sensors available from FG Sensors. These sensors are very similar to the sensors once produced by Speake & Co (long out of business). The FG-3+ sensors output a variable period square wave based on the magnetic field strength and direction. The frequency of this square wave typically ranges between 40kHz to over 120kHz.