A read head for a Wiegand wire has two C-shaped ferro-magnetic yokes in lateral alignment with one another, two magnets sandwiched between respective first and second legs-of the yokes, and a pickup coil wound on one of the legs of the read head. One magnet has a first polarity adjacent to the first...http://www.google.com.au/patents/US5898241?utm_source=gb-gplus-sharePatent US5898241 - Read head for Wiegand token
