slow voltage fade circuit

Discussion in 'The Projects Forum' started by lefevrej, Apr 16, 2009.

  1. lefevrej

    Thread Starter New Member

    Apr 16, 2009
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    Hello- I need to create a circuit which provides a slow voltage reduction over time. This is an application which simulates a sensing device, so is very low power application. Specifically, I have a 5V DC reference voltage which I need create an output from 4.5V to 0.5V over a period of 3 hours or so. I would like to include a pot of some sort to vary the rate of decay. Could someone get me pointed in the right direction?

    jl
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    We used to do something like that for testing chart recorders. The circuit applied a slow clock to a couple of counter IC's that fed a D to A converter. Your app can reset the counters to maximum and count down at the correct rate for the 3 hour period.
     
  3. lefevrej

    Thread Starter New Member

    Apr 16, 2009
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    0
  4. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
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