A magnetic device includes first and second electrodes and a sensor stack
connected to the first and second electrodes proximate a sensing surface
of the magnetic sensor. A resistive element is connected to the first and
second electrodes in parallel or in series with the sensor stack and
adjacent the sensing surface. In some embodiments, the resistive element
is configured to generate signals related to changes in its resistance. A
controller to respond to the resistive element signals can also be
included.