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Digital frequency counter panel?

Discussion in 'Electronic Design' started by Ignoramus5533, Oct 25, 2005.

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  1. Is there some easy way to add a small LCD or other digital panel with
    a frequency counter, to a circuit? I was thinking of attaching that to
    the actual welder. I have separate frequency counters, but would like
    to know if there is an easy way to add a digital panel.

  2. Guest

    A OEM Basic stamp and a LCD work great up to 60 Khz or so, with ~1 hz
    resolution, use a prescaler before that ie divide by 10 or 100 or 3 or

  3. I see. Thanks. Well, I will wait with doing it.


  4. Depends on how accurate you need.

    You can get inexpensive (<$30) 3-1/2 digit panel-mount voltmeters, with LCD
    readout. For instance, Jameco part 108388CJ, for $13. Then all you need is
    a frequency-to-voltage converter; e.g., LM2917 and a couple of resistors and

    If you go this route, be aware that these inexpensive voltmeters usually
    need a 9v supply that is *isolated from ground* - in other words, the power
    supply ground can't be the same as the signal ground. There are various
    ways around that limitation, the easiest of which is just to use a 9v
    battery - they don't draw much current, the battery will last a long time.
  5. This is the perfect answer, thanks.

  6. Chris Jones

    Chris Jones Guest

    Someone has programmed a PIC16C84 or 16F84 to do this up to about 40MHz,
    with a standard LCD panel (anything that uses a HD44780 chip or clone
    thereof). Google for pic frequency counter. I think the ham radio people
    like them.

    I was meaning to write one that could do reciprocal counting to get fast
    updates on low frequencies but I never got around to it, partly because I
    got a very nice HP counter second hand so my motivation reduced.

  7. Jasen Betts

    Jasen Betts Guest

    where do you get stable enough parts to get 3.5 didgts precision?

  8. Just because the meter can display 3.5 digits doesn't mean the problem
    requires that much precision. The OP didn't say anything about how much
    precision he needs, but from context of other posts I'm guessing that he
    just needs to know order of magnitude.
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