Electronics – Report 3
Yashvardhan Singh (230959136)
Group 1 - Taskphase
Electronics Subsystem
I.
1D ACCELEROMETER SENSORS
An accelerometer is an electromechanical device that senses
the acceleration of an object. The 1D in its name refers to
One dimension. It measures motion, vibrations and shocks
and converts them to an electrical signal which can be
measured and recorded.
II.
MECHANICAL ACCELEROMETERS
Seismographs use mechanical accelerometers to monitor
acceleration along the vertical axis. It functions according to
mechanical principles and often makes use of a mass-spring
system. When the accelerometer is subjected to vertical
acceleration during movements, a mass suspended by a
spring moving in relation to the accelerometer's frame. The
vertical acceleration brought on by movement is represented
by an electrical signal that is translated from this relative
movement. This instrument is crucial to seismography
because it allows for the precise recording and analysis of
seismic events, notably the vertical ground motions that
occur during earthquakes.
III. PIEZOELECTRIC ACCELEROMETERS
A sensor that uses the piezoelectric effect to measure
acceleration in a single direction is known as a 1D
piezoelectric accelerometer. When subjected to mechanical
stress or vibrations, certain materials exhibit the
piezoelectric effect, which causes them to produce an
electric charge.
A piezoelectric substance is found inside the accelerometer.
The piezoelectric material is mechanically stretched or
deformed when the accelerometer experiences acceleration
or vibration along the axis it is measuring (often in one
dimension).
Due to the piezoelectric effect, the mechanical stress placed
on the piezoelectric crystal causes it to produce an electric
1
charge. The charge and applied acceleration are precisely
proportional.
The electronics of the accelerometer then measure and
transform this created electric charge into a digital voltage
signal.
IV.
CAPACITIVE ACCELEROMETERS
They incorporate the principles of capacitors to
They have a proof mass which is attached to a substrate and
the proof mass has sense fingers, which lies between
electrodes but never makes contact with them. This makes
up a differential capacitor. As the proof mass moves, the
capacitance between the top and bottom plate changes
which is then amplified and eventually converted to a digital
format (as seen in the block diagram) in order to use this
input data.
sensor, allowing for the calculation of the applied
acceleration.
c) Piezoresistive Accelerometers
A piezoresistive accelerometer measures acceleration using
the principle of piezo resistivity. It contains tiny resistors
that change their electrical resistance in response to
mechanical stress caused by acceleration. As the
accelerometer experiences acceleration, the resistors'
resistance changes, providing an electrical signal
proportional to the applied acceleration.
V.
OTHER ACCELEROMETERS
a) Hall Effect Accelerometers
They incorporate almost the same structure as that of a
regular hall effect setup. Apart from it, the magnets are
simply changed as to face each other and attach it to a
mechanical accelerometer, it provides everything to measure
acceleration. When the accelerometer moves upwards a hall
voltage is generated, and similarly another hall voltage
(opposite direction) is generated when it moves downwards.
b) Thermal accelerometers
A thermal accelerometer measures acceleration using the
principle of heat transfer. It typically consists of a heated
mass and a temperature sensor. When subjected to
acceleration, the mass moves, causing a change in
temperature. This change is detected by the temperature
2
• Commercially used 1D Accelerometers
AC980 Accelerometer is one of the 1d accelerometers used
commercially.
REFERENCES
[1]
[2]
[3]
[4]
[5]
https://youtu.be/OHGzvnMFH0k?si=Pi9RFCe6ATFwduqo
https://youtu.be/q4_VZte-8wg?si=2uTGJMy_gc4kECBh
https://youtu.be/i2U49usFo10?si=sKZ5UdJzxByoWDC9
https://youtu.be/KuekQ-m9xpw?si=Q-IXwmls1b9SIdRr
https://ctconline.com/datasheet?type=Sensor&prd=AC980