| 摘要 |
A read head for a Wiegand Wire has a low reluctance core on which a pick-up coil is wound. The Wiegand Wires are passed over a face of the core and coil and switch state directly over the core and coil so that the change in the magnetic field is coupled to the coil to produce an output pulse. Outboard of the direction in which the Wiegand Wires travels are first and second magnets that generate the field. In contact with these magnets and bridging both sides of the coil are first and second magnetic shunt members which control and determine the shape of the field. A first magnetic shunt member has a relatively narrow bridge portion which saturates under the field involved and thus there is a large leakage field adjacent to the face of the read head for the purpose of appropriately setting the Wiegand Wires. The second shunt has a much larger bridge portion so that there is much less leakage flux. However this smaller leakage flux is in the opposite direction from the leakage flux from the first shunt. The leakage flux from the second shunt serves to establish, accordingly, a negative field having a magnitude sufficient to reset the Wiegand Wire. In this fashion the two magnets and two shunts determine the strength and configuration of the field.
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