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sensors etc.

Discussion in 'Mathematics and Physics' started by PG1995, May 30, 2014.

  1. Pommie

    Pommie Well-Known Member Most Helpful Member

    Mar 18, 2005
    Brisbane Australia
    A voltage divider with a smoothing capacitor can be sampled very fast. The acquisition time is the time it takes to charge the internal 10pf capacitor. When it is in parallel with a much bigger (10uf) cap it charges very quickly. An opamp is not needed.

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  2. flatfootskier

    flatfootskier Member

    Jan 11, 2007
    Here's where I make a fool of myself maybe...anyway here goes, in the interest of learning.
    Potential divider 100k and 20k
    30V worst case input delivers 5v, ignoring input impedance of ADC. consumes 250uA = 7.5mW
    Small capacitor across the ADC input, determined by the required response time.

    That said, I think this is possibly a moot point for this design - the voltage or current from the panel is predominantly determined by the load connected to it, assuming its being used to harvest energy, rather than just drive an ADC. There's some great heliostat designs using LEDs as photo detectors, which tell the panel which way to drive, assuming that's the application.

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