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Output voltage of Crystal Oscillators

  1. Sep 30, 2012 #1
    I am currently building a circuit that produces a 200khz signal with a potential difference of 3 - 12 volts, depending on the force applied to a strain gauge. The input voltage is a 12V, 50hz source. With no force applied to the strain gauge, the output is to be 3V and 12V at breaking force.

    From my research I discovered that I can use a crystal oscillator to produce the 200khz signal, except I am having trouble understanding exactly how the component works and its output voltage. Should I convert the input voltage to DC, then run it through the oscillator and the voltage of the input DC will be the voltage of the 200khz signal produced by the oscillator? That is, is the voltage input the same as the output (perhaps a small decrease due to the resistance of the component) across this component?

    Thanks in advance.
  2. jcsd
  3. Sep 30, 2012 #2
    It's not what you think. It's more like a high-Q RLC resonator. It doesn't do anything unless you connect it to the right kind of amplifier. The whole thing is then a 200KHz oscillator.
  4. Sep 30, 2012 #3
    What is the standard price range on these amplifiers, and once I connect the oscillator to the aforementioned amplifier, how can I determine the output voltage? Or alternatively, is there an easier way to convert the 50hz signal to a 200khz signal?
  5. Oct 1, 2012 #4


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    Staff: Mentor

    A crystal oscillator is a transistor circuit with a dozen or so components, and including a quartz crystal in a hermetic package. Like most electronic circuits, it will require a regulated DC supply. This oscillator will in turn give a constant frequency output, of fixed amplitude. Each crystal is designed for a specific frequency and this cannot* be changed.

    You could just as easily construct a 200kHz oscillator using C's and R's around a transistor or op-amp. The crystal oscillator usually has a more accurate frequency, though, this is sometimes important.
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