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Driver lever for QCM sensor

Hi all
I think I have a interesting question about design electronic for QCM sensor
As far as I know that QCM circuit is only a oscillator circuit with the frequency output controlled by value of QCM sensor. that's all.
But problem in here is that " How can we calculate the level of voltage we must supply to QCM sensor ? " when we make a QCM circuit with any topology like: Pierce, Miller, Coppits,...

I remember that in a textbook " Crystal Oscillator Circuits", page 6 of Robert J. Matthys, he said that the driver lever for Quartz crystal depend on its frequency. Ex: 10MHz ~ 2.5 - 3V

Does anyone have opinion about this ?

Best regards

Nhan Ngo Dinh

Comments

  • Yes you are right. openQCM circuit consists of a quartz crystal oscillator circuit in Pierce configuration. The frequency output is measured by the arduino microcontroller.

    It is really interesting to calculate the voltage we must apply to QCM sensor, because it is related to the change in motional resistance of quartz crystal and then to the damping of the resonator.

    Oscillators circuit may incorporate an Automatic Gain Control (AGC) system. The AGC mantains constant the signal level of the oscillator by providing a voltage that modifies the gain of the amplifier. You can measure the level of voltage you must supply to QCM sensor by measuring the AGC voltage.

    You can read more about Automatic Gain control system in Arnau's paper "A Review of Interface Electronic Systems for AT-cut Quartz Crystal Microbalance Applications in Liquids"
    http://www.mdpi.com/1424-8220/8/1/370/htm#b69-sensors-08-00370
  • This paper is only review paper, just overall, not specific circuit. Anyway thanks so much for your feedback.
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