Book Analog Interfacing to Embedded Microprocessors
The resulting voltage at the movable beam is
zero. When force is applied to the beam, it moves closer to one of the fixed
plates. This causes the capacitance between the movable beam and that plate
to be higher, and the capacitance between the beam and the other plate to
be lower. The result is that the closer plate couples more signal into the beam
and the farther plate couples less. The output voltage is a function of the dis-
tance the beam was deflected.
The Analog Devices ADXL05 is a typical acceleration sensor. The ADXL05
generates an output voltage that represents the degree of acceleration. Exter-
nal resistors set the output voltage anywhere between 200 mv/g and 1 v/g. The
output of the ADXL05 can be connected directly to an ADC. The ADXL05
comes in a 10-pin package.
Solid-state acceleration sensors measure acceleration in one dimension. If
you need to measure acceleration in two dimensions, you will need two
sensors
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