building a 555 hysteretic oscillator

Discussion in 'The Projects Forum' started by hillshaveeyes57, Sep 27, 2012.

  1. hillshaveeyes57

    Thread Starter New Member

    Sep 12, 2012
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    the schematics are right, but i'm not getting anything! yeah, this is my first project and i messed up a lot of times but the last few, i've gained a little more insight as to how it works and i'm still not getting my leds to flash OR even light up. i was thinking maybe i either wore out the protoboard (i used oversized hookup wire the first few times then downgraded to something smaller that fit into the slots better) or that my components are incorrect, or i fried something, even though i replaced the capacitor, pentometer, and 555 twice.

    i'll try to post some pics of the project later.
     
  2. Dodgydave

    Distinguished Member

    Jun 22, 2012
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    Schematic and pictures please....
     
  3. tracecom

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  4. help_mum

    New Member

    Sep 13, 2012
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    Why don't you get LTSPICE or one of the others and run your circuit on it then move to the Bread Board, Hase saved me hours of work and cost of parts.

    H_M
    Beginner
     
  5. hillshaveeyes57

    Thread Starter New Member

    Sep 12, 2012
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  6. tracecom

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    Where's the 555?
     
  7. hillshaveeyes57

    Thread Starter New Member

    Sep 12, 2012
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    it fell out right before i took the pics and i just accidentally left it out.

    the breadboard was kind of loose because the first hookup wire i used was a higher guage...almost too big for the slots.

    think i should return the breadboard cause it might be FUBAR?
     
  8. hillshaveeyes57

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    Sep 12, 2012
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  9. tracecom

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    Apr 16, 2010
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    I don't know about returning it, but it's probably ruined. Even the wire in the pictures looks too big. I don't use wire bigger than 22 awg.

    Just for reference, here's my version of the circuit you are trying to build. It works.
     
  10. hillshaveeyes57

    Thread Starter New Member

    Sep 12, 2012
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    i thought the wire was too large but was going to try to get away with it. that and i cheaped out and didn't buy a wire cutter and the ends were kind of crap when i was hooking it up. i'm returning it, getting some smaller guage and i'll give your design a try too. i know there's more than one way to skin it, but i'm still new at this whole thing. thanks so much for the feedback.
     
  11. hillshaveeyes57

    Thread Starter New Member

    Sep 12, 2012
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    about your design though if i start trying to assemble it.
     
  12. Wendy

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    Mar 24, 2008
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    A side comment, the pictures are pretty accurate. The wires lay flat, the components are flush.

    You will find in this hobby neatness is critical. It makes errors easy to spot, it prevents things like short. I have several kit boxes I put my project parts in, just because they are completely reusable.

    I will rebuilt this project and take pictures, to show what I am talking about. Like I said, this project is verified, and is very repeatable. I went to a lot of effort to make it so. The pictures will be on file for future use, so they will be available for other use. I am a devote pack rat.
     
  13. Audioguru

    New Member

    Dec 20, 2007
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    Ho, ho, hee, hee.
    Sorry but I always laugh when I see your messy tangle of wires that are much too long on a protoboard.

    Of course the contacts are ruined.
     
  14. hillshaveeyes57

    Thread Starter New Member

    Sep 12, 2012
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    the wire is 22 ga i think. fits into the holes fine, comes out fine. a csr at radioshack told me that it might just be having trouble making it through the circuit cause my wires are too thick. is that possible?

    i hooked it up on fresh breadboard last night and did everything right and all i got was the two leds to light up. excuse my language but i'm really pissed. i don't think i've ever had this much trouble with anything. i'm just angry as hell about the pentometer not working. i've bought two tried both. the capacitor is fine.
     
  15. hillshaveeyes57

    Thread Starter New Member

    Sep 12, 2012
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    yeah. i guess it is pretty funny. do you think too much wire could have something to do with the pentometer not registering?

    dammit to hell i just want it to work already!!!!
     
  16. hillshaveeyes57

    Thread Starter New Member

    Sep 12, 2012
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    and bill if you do decide to rebuild it will you please take pictures and post? thanks.
     
  17. Wendy

    Moderator

    Mar 24, 2008
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    Guaranteed, I would have done it already except I have misplaced most of my short breadboard. I'm going to run to Tanners or the Shack and pick up a few more. I'll take lots of pictures.

    This thread shows a few of my kit boxes.

    http://forum.allaboutcircuits.com/showthread.php?t=68676
     
  18. tracecom

    AAC Fanatic!

    Apr 16, 2010
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    No. Don't forget that many of the CSR's at Radio Shack were at Shoe Carnival last week and will be at Pets R Us next week.
     
  19. Audioguru

    New Member

    Dec 20, 2007
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    Your wiring is too messy for us to see if THIS IS CONNECTED WRONGLY TO THAT.

    The potentiometer is supposed to be a variable resistor. When it is 10k ohms then it charges and discharges the capacitor slowly so the LEDs blink back and forth slowly.
    When it is zero ohms then the 10 ohm resistor charges and discharges the capacitor very quickly then both LEDs appear to be on all the time.
     
  20. tracecom

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    Apr 16, 2010
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    AG may have hit on the problem. In order to use the potentiometer as a variable resistor, you can connect the wiper (middle terminal) to one of the other terminals (either one.) Then, use the two end terminals as shown in your circuit. See if that is the problem.
     
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