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Struggling to do my own ELectronic Stuff?

Discussion in 'General Electronics Chat' started by fouadalnoor, Jun 19, 2011.

  1. SABorn

    SABorn New Member

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    What resistors?
     
  2. fouadalnoor

    fouadalnoor Member

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    The Pull up ones. I get how they work, I just dont know how you know they have to be say 10k or 5k.. how do you calculate that?
     
  3. fouadalnoor

    fouadalnoor Member

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    Can you guys please double check my circuit one last time. After this check I will be ordering it from PCB Train so hopefully I haven't made an obvious mistake.

    Thanks! (the circuit is attached to post #80)
     
    Last edited: Jul 23, 2011
  4. dave

    Dave New Member

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  5. SABorn

    SABorn New Member

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    The Lm311 has no connection to pin 3 ???

    I have not worked with the LM311 so i am unsure if pins 5 and 6 (Balance and strobe) require to be tied high or low or are able to be left floating as you have them, although a quick look at a data sheet shows them not included in some circuit examples so think you can leave them floating.

    As for the pullups the picaxe manual recommends 4K7 to 10K as you dont want to be to low in resistance as its a waste of power that needs to be sunk, then you dont want too high of impedance either.

    Pete.
     
  6. fouadalnoor

    fouadalnoor Member

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    Well pin3 on the PIC is supposed to be the "switch" that will turn the device ON. Its supposed to be connected to the gas nob and as it moves around the pin would go LOW (I need to change my program accordingly...)

    Basically I want pin3 of the PIC to be HIGH when the nob is at it's initial position, but as soon as I turn it around it will go LOW (I will do this mechanically...its a little hard to explain..)
     
  7. SABorn

    SABorn New Member

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    You didnt read correctly............I said pin 3 of the LM311..................
     

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  8. fouadalnoor

    fouadalnoor Member

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    ahh...yeah your right! I forgot to actually connect pin3 to the resistors...

    Its not fixed and attached.
     

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  9. SABorn

    SABorn New Member

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    Now you have removed the pull down resistor from the PICAXE PIN3 creating a dead short when the switch is pressed.
     
  10. fouadalnoor

    fouadalnoor Member

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    haha, yeah well spotted (what was I thinking?!). So I am guessing a 10k pull down resistor on the third pin is okay?
     

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    Last edited: Jul 24, 2011
  11. SABorn

    SABorn New Member

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    That looks better, i see no more obvious mistakes.
     
  12. fouadalnoor

    fouadalnoor Member

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    Right, neither do I... I shall order it now I guess.
     
    Last edited: Jul 25, 2011
  13. fouadalnoor

    fouadalnoor Member

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    Okay, its ordered.. £56.47 from PCB train. Hopefully it's okay.
     
  14. SABorn

    SABorn New Member

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    WHAT????? 56.47 ??? bloody hell!!! i know now why i make my own boards, Gee you could have set up a nice little board making hobby kit for that.

    If you were a little closer i would have made the board for you in less the 20 minutes for about 2 quid.

    You could of had 10 boards made and fully assembled with parts, including postage, in China for less than what those sods are charging you to make 1 PCB.

    PS:- think they should change their name from PCB Train to PCB Bandwagon!
     
    Last edited: Jul 25, 2011
  15. fouadalnoor

    fouadalnoor Member

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    haha, I KNOW (and I'm a student as well...) I WILL buy all the stuff and start making my own boards soon enough (I want to get this project quickly out of the way so I can make room for other things :) )
     
  16. fouadalnoor

    fouadalnoor Member

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    Hahah, you know what! Next time il just pay YOU to do it (better than paying some random company...)
     
  17. SABorn

    SABorn New Member

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    Considering the amount of time it has taken you to design the board, i could have made it and posted it by the imperial fleet with captain Cook and you would have had it by now.

    Then again the exersize was to get you to learn a little of how to design a board, and not to break any speed records.
     
  18. fouadalnoor

    fouadalnoor Member

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    Haha, yeah I am quite the noob when it comes to all this stuff so its been an invaluable experience! After I finish this project I will probably do something a little more complex and hopefully will do it better/more efficient!
     
  19. fouadalnoor

    fouadalnoor Member

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    oh...now they want me to give them the " Gerber files" so I need to convert the files that I have (which is'nt easy..). I was thinking, how about I just pay you for the shipping/materials and you make it for me? I would much rather that then pay some company... whatcha think?
     

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