Bonjour,
s'il vous plait quelqu'un peut m'aider a comprendre le fonctionnement de ce type de capteur?
<<Its working principle is as follows:
Signal Source outputs a high-frequency carrier-wave signal that loads on the
pole-boards of the capacitor transducer. When the ground is still, the
acceleration input is zero and at that time if the mechanical zero-position
adjusting is good enough, the mid pole-board should be in the right center
between upper and lower pole-boards and therefore the output voltage of the
accelerometer should be zero too.
When the ground is moving, the comparative displacement between mid
motionless board and upper & lower boards that fastens the end of the reed
happens, which leads to the departure of mid board from the center of upper and
lower boards, and meanwhile an AC signal the frequency of which is the same as
that of carrier wave will be sent to the input end of amplifier 1 and output to
demodulator after it is amplified.
The demodulator completes the synchro demodulation and filtering towards input
AC signal according to synchro signal from signal source and at last gets an
output signal that is proportional to the departure displacement of capacitor poleboard
from the central position.
In order to improve the performance of elastic oscillation system formed by reed
and upper & lower capacitor pole-boards, part of the electronic signal is taken
out from the output end of the accelerometer and loads to the feedback coil
through feedback loop. The feedback coil is connected to the capacitor poleboard
and placed within the magnetic field produced by permanent magnet.
The current in the feedback coil produces the force that is against the motion of
the pole-board under the action of the magnetic field, which therefore changes
the performance of the mechanical oscillation system and makes the closed-loop
mass to meet the demands of prospective performance.>>
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