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Disturbance Sensor

• Simple circuit for laptop computers, portable devices, etc. for detecting change in location (i.e. rotational movement). The HMC1021S is placed on a horizontal circuit board in a magnetically clean area.
• 10-bit to higher ADC's recommended for best resolution. Software should allow for slow drifts in value, but trigger for disturbances if sudden value changes in many ADC counts.
• Gain set at 200 like compass circuits, but can be from 100 to 300 V/V or wider if desired.
• Both digital and manual set pulse switches shown. NPN transistor must be high beta.
• This design can be used at 3.0 or 5.0 volt power supplies.