Project: TTL Logic probe.

Discussion in 'The Completed Projects Collection' started by bertus, Apr 12, 2009.

  1. bertus

    Thread Starter Administrator

    Apr 5, 2008
    15,648
    2,347
    Hello,

    Here I have designed a TTL Logic probe with pulse detection.

    [​IMG]

    I hope the drawing is clear enough.

    Greetings,
    Bertus
     
    Last edited: Apr 13, 2009
  2. electronictech

    Active Member

    Apr 1, 2009
    35
    0
    Nice circuit!
    I would have designed the circuit so that a logic low would give a '0' on the LED display, a logic high would give a '1', and a pulse would give a 'P'........also would replace the TTL with a 8-pin 8-bit micro like a 12F675 so as to make the final PCB as small as possible, also the 12F675 has a wide operating range (2.0-5.0V), so you would be able measure logic from 5V to 2V, if you use the logic circuits power supply.
    The 12F675 might work at 1.8V, but haven't tried it.
     
  3. bertus

    Thread Starter Administrator

    Apr 5, 2008
    15,648
    2,347
    Hello electronictech,

    I want to show the pulse type and not only levels H and L or 1 and 0.
    With the probe you can also detect needle pulses with mainly high or mainly low.
    The needle pulses can be only a couple of micro seconds wide, the mono flop will stretch the pulses to make them visible.

    Greetings,
    Bertus
     
    Last edited: Jan 11, 2013
  4. ericlai

    New Member

    Jul 8, 2009
    1
    0
    hello bertus, is there any simpler circuit for TTL logic probe using only leds which represents high and low........and with audio output....??? I'm designing a TTL logic probe that must have a clear visual and audio indications of high and low logics....can u help me with this???
     
    Last edited: Jul 8, 2009
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