Cannot get a 555 timer chip to work on a breadboard

Discussion in 'Homework Help' started by J_Rod, Nov 4, 2014.

  1. J_Rod

    Thread Starter Member

    Nov 4, 2014
    109
    6
    The chip I am trying to use (picture with astable mode diagrams):
    http://www.555-timer-circuits.com/operating-modes.html
    Here is my breadboard so far with this timer 555 chip:
    555 circuit.jpg
    I want to use astable mode, but am unsure how to proceed. I want to drive a clock pulse to some
    D flip flops on the breadboard. No one ever taught me how to hook up capacitors and resistors on the breadboard and I am no self teacher. I used a logic probe, but there is no pulsing output at pin 3 like I think there should be, just low voltage. For R1: 220ohm, R2:100k ohm, C: 10uF, second capacitor: 0.01uF. Again there is no output at all, low voltage, and also 220ohm resistor is heating rapidly.
    Any help is greatly appreciated!
     
  2. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
    2,809
    834
    It looks like both legs of the 0.01uF capacitor are in the same row, effectively shorting it out. Hard to tell from the picture.
     
  3. ericgibbs

    AAC Fanatic!

    Jan 29, 2010
    2,503
    380
    hi.
    I agree with 'dj', pin #5 is at oV, due to the cap... sharpened your image.
    E
     
    J_Rod likes this.
  4. J_Rod

    Thread Starter Member

    Nov 4, 2014
    109
    6
    How should I rewire the circuit? I tried to follow the diagram from the site. I may try to remove the smaller capacitor, then, as well.
     
  5. MrChips

    Moderator

    Oct 2, 2009
    12,446
    3,361
    Remove that yellow wire on pin-5 of the 555 timer and see if it works.
     
  6. Alec_t

    AAC Fanatic!

    Sep 17, 2013
    5,800
    1,104
    Try swapping the two resistors over.
     
  7. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    3,373
    1,159
    Attached is one way. I'll look at your picture closer to check for errors.
     
    J_Rod likes this.
  8. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    3,373
    1,159
    This is how you made the circuit.

    Note that I had to use three wires to make it from pin 2 to the timing capacitor where you just looped over to it.

    You have the 220 resistor going from pin 7 to ground.

    on edit, added your picture ... just the 555
     
    Last edited: Nov 4, 2014
    J_Rod likes this.
  9. J_Rod

    Thread Starter Member

    Nov 4, 2014
    109
    6
    Oh my gosh, thanks so much this solution works! It's so cool because I used the logic probe to check and it is switching at pin 3 from high to low.
     
  10. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    3,373
    1,159
    Your wiring and eventual troubleshooting, is made easier IF you route your wires neatly.

    That is the lesson you just learned.
     
    J_Rod and atferrari like this.
  11. J_Rod

    Thread Starter Member

    Nov 4, 2014
    109
    6
    Yeah, definitely will need to make my board neater for future projects. I try to reuse wires so I don't cut them up too small, or bend the edges at right angles, but I guess that's fine to bend them like that so they are lower to the board?

    This might belong in another thread but it's related... so, all rows on the breadboard in between positive and negative columns are like a single wire? Also, why do we have to place DIL chips across the gap between the rows? Is it because there cannot be multiple inputs to a pin?
     
  12. MrChips

    Moderator

    Oct 2, 2009
    12,446
    3,361
    This is the connection pattern on your breadboard:

    [​IMG]
     
    J_Rod likes this.
  13. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
    2,809
    834
    J_Rod likes this.
  14. J_Rod

    Thread Starter Member

    Nov 4, 2014
    109
    6
  15. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    3,373
    1,159
    J_Rod likes this.
  16. J_Rod

    Thread Starter Member

    Nov 4, 2014
    109
    6
Loading...