Do you need a cheap timer?

Discussion in 'General Electronics Chat' started by hp1729, Apr 4, 2016.

  1. hp1729

    Thread Starter Well-Known Member

    Nov 23, 2015
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    At the local dollar store I found a pedometer. A bouncing weighted switch note foot steps, so I removed the weighted switch and ran wires out for an external connection. It works okay on seconds or slower but isn't too good faster than that. You can't beat $1.00 for a display. Just add an oscillator for what ever you want to count. If you get one that runs on a 3 V battery you could also use it to power a CMOS oscillator.
    How much accuracy do you need in the oscillator? Counting hours, an accuracy of 1/2 hour a day means an oscillator accuracy of about 2%. Easily attainable with a 7555 oscillator.
     
  2. RichardO

    Well-Known Member

    May 4, 2013
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  3. hp1729

    Thread Starter Well-Known Member

    Nov 23, 2015
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  4. dannyf

    Well-Known Member

    Sep 13, 2015
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    a real timer is just a couple dollars, with buttons and lcd read-out.

    As to cheap calculators, they are a great source for inexpensive 8-10 digit LCD displays.
     
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