Ehsan Darabi

  Abstract:

  To provide a sensor for attitude determination system of a satellite, the idea came up to construct an instrument able to measure the earth's approximately constant magnetic field. There are a few procedures to get along with the matter among which the "Flux-Gate" seems most appropriate for the situation. Based on a specific viewpoint that is offered throughout the current thesis, a Flux-Gate magnetometer is divided to 3 separate issues; "Excitation Circuit", "Sensitive Part or Sensor Head" and "Output Electronic Circuit". Sensitive part composing two sets of winding known as excitation and pick-up coils beside a ferromagnetic core is supposed as our Flux-Gate's heart. Excitation circuit provides a periodic current through excitation winding and causes a regular and distinct change to core's magnetic state and also large enough to magnetically saturate the core. When saturation occurs, core's reluctance suddenly collapses and permits the external flux inside the core. Thus a periodic voltage typed signal turns up at Pick-Up coil. The finishing task is to process the picked up voltage so that both magnitude and direction of the DC magnetic field nearby the sensor head exactly measured. Also there are a few sources of uncertainty inside those three units that may cause errors to extracted DC voltage. They are briefly described in the text.

  Presentation time and place:

  5:00 P.M., Sunday, July 18^th, 2010

  Seminar Hall, Electrical engineering faculty