555 Nightmare...lol...light stays on...

Discussion in 'The Projects Forum' started by Lineout, Jul 3, 2014.

  1. Lineout

    Thread Starter Member

    Nov 20, 2013
    64
    0
    Hi ,


    I've done this with a dozen different circuits, and none of them work.

    I have a pkg of 10 NE555's tested 7 of them in a lot of the circuits I put together, I have 3 left (555's) that I haven't taken out of the pkg yet.

    Don't know if the whole batch is bad or I just am doing something
    very wrong....

    I ordered what I think is a 555 test module from ebay, don't know if that
    will help.


    Edit: ASTABLE



    ...
     
  2. Dodgydave

    AAC Fanatic!

    Jun 22, 2012
    5,003
    745
    Ok whats the circuit your making, have you got a breadboard jig?
     
  3. Lineout

    Thread Starter Member

    Nov 20, 2013
    64
    0

    I've been using a breadboard.

    So many circuits, I don't know where to start, I think I'll youtube a
    'breadboard 555' query and copy someones exactly and see if that
    will show me anything.

    Also wonder if the whole batch could be bad, and if I need to wear
    a wrist esd strap, thought there's not mutch statice this time of year
    here.
     
  4. wayneh

    Expert

    Sep 9, 2010
    12,154
    3,061
    Take a deep breath, slow down, and show us ONE of the circuits. Tell us what the goal is (the schematic you are following), and show us a good picture or 2 of your build. Don't forget to describe your power supply.

    You can find horror stories about counterfeit ICs out there, but I would estimate the odds are very low of that being your problem. It's much more likely some simple mistake that a second set of eyes will help find for you.
     
  5. Lineout

    Thread Starter Member

    Nov 20, 2013
    64
    0
    Dead Camera.
     
  6. Sparky49

    Active Member

    Jul 16, 2011
    834
    417
    Do you need a camera to do this?

    Simply writing "Dead Camera." is going to solve nothing.
     
  7. inwo

    Well-Known Member

    Nov 7, 2013
    2,435
    315
    Here's a simple test circuit for 555.

    [​IMG]

    Good 555 = blinks
     
  8. DerStrom8

    Well-Known Member

    Feb 20, 2011
    2,428
    1,328
    Something I'd like to point out--if your resistor values or capacitor value is too low, the LED will blink so fast you won't be able to tell it's blinking--it'll just look like it's constantly on. Use the circuit inwo posted. However, 1k and 10k resistors with a 10uF capacitor will cause it to blink at around 7Hz, which may be too fast for you to tell, depending on how good your eyes are. I suggest using a 10k and 100k instead of the 1k and 10k respectively. this will blink at 0.7Hz, which will be much easier to see.
     
    Alec_t likes this.
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