EE 4BD4 Lecture 14

Position Sensors

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Types of Sensors• Potentiometers and linear resistors • Capacitive sensors (mm distances, e.g.

capacitive microphone)• Linear variable differential transformer (LVDT)• Hall Effect sensors• Optical encoders• Accelerometers

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Basic Approach (not direction sensitive)

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Phase –Sensitive Detector for Direction

• Excitation signal between 50 Hz and 25kHz (10 times greater than frequency of movement)

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Alternate Processing Approach

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AD598 Signal Conditioner (Simplified)

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Hall Effect Voltage VH

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Analog Devices Magnetic Field Sensor(Linear output)

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Setting Gain of the Chip

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