Hands on Homework issues?

Discussion in 'Homework Help' started by pfelectronicstech, Oct 3, 2012.

  1. pfelectronicstech

    Thread Starter Member

    Jan 18, 2012
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    4
    Ok I'm in the home stretch here, just a few more exams to go before I graduate. I'm onto a hands on wiring/components parts part of the course. You have a briefcase size piece of equipment to wire parts on.

    I'm supposed to wire a IC358 dual op-amp with resistors. Three 1 K-ohm resistors and 100 K-ohm resistor with 10 microfarad capacitor too. Its supposed to make one of the LED's blink, but mine is on solid instead of blinking. I need it to blink because that is what its supposed to do, and because its a question too. They want me to record how many times the LED blinks in 60 seconds. I believe it will be 30 times, but thats just a guess. I know this hard to diagnose from where you are, but any suggestions? Thanks for any help, again.
     
  2. DumboFixer

    Active Member

    Feb 10, 2009
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    Well, supplying a schematic would be a good place to start :)
     
  3. bertus

    Administrator

    Apr 5, 2008
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  4. pfelectronicstech

    Thread Starter Member

    Jan 18, 2012
    178
    4
    I got it to blink, I finally got it. I was using the wrong resistor. Resistors are really pains in the butts to see. I have great eye sight too, lasik eye surgery a few years ago. Yellow in very hard to see on resistors. Well I got it to blink, and its around 3o blinks per go seconds. Fun doing trouble shooting on a circuit I out together. Stayed tuned guy I have LOTS, I mean LOTS more experiments to do.
    Oh by the way the schematics are in my books, how can I post them on here? I'm not the most computer savvy guy mind you, I do what I can. Thanks for the help.
     
  5. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    If you want to post the schematic from a book, you can scan it on a flatbed scanner or take a picture with a digital camera.
    In the FAQ is given how to attach it:
    Attachments and Images

    The popup will give you the maximum size you can use.

    Bertus
     
  6. pfelectronicstech

    Thread Starter Member

    Jan 18, 2012
    178
    4
    Thanks bertus, I will give that a shot if I run into more trouble. It certainly was fun troubleshooting my own work. Finding out what was wrong, then fixing it.
    I'm trying to email every electronics tech employer in my area to see if they need or will hire a junior tech that will graduate soon. No bites at all yet. Should I expect someone to take a chance on a student ET for a junior technician job or its futile till I actually graduate with a diploma? Thanks again for the help guys.
     
  7. Audioguru

    New Member

    Dec 20, 2007
    9,411
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    You get what you pay for.
    Cheap Asian resistors use cheap paint for the colour stripes. Yellow, brown and red look almost the same. Green and blue look almost the same.

    I got cataracts in my eyes so I had the foggy and yellowed lenses replaced. Now every colour is vivid and different (your old lenses probably make everything look yellowed).
     
  8. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    3,373
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    When in doubt ... break out the ohm meter. My eyesight is going bad ... as reading chips are blurry (I use reader glasses now), but I will breakout the extra magnifier if necessary and whatever meter I might need to verify components.
     
    pfelectronicstech likes this.
  9. pfelectronicstech

    Thread Starter Member

    Jan 18, 2012
    178
    4
    Thank you Joejester. Even with the magnifying glass the colors seems to be faint. The ohm meter suggestion is a good idea, thanks.
     
  10. bountyhunter

    Well-Known Member

    Sep 7, 2009
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    We used to have a lab rat named Fran who frequented electronics swap meets, had tons of resistors. I remember I needed some to build up some demo borads real fast, put them in: we always defluxed the boards using acetone. The stuff melted away all the color stripes on the resistors. Not a trace of color left, just bare naked resistors.

    They worked though.....
     
  11. bountyhunter

    Well-Known Member

    Sep 7, 2009
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    Funny how many resistors I find "out of spec" when I do that. I have a set of .01% tolerance resistors to keep my meters calibrated, but a lot of 5% resistors I check are out of tolerance spec.
     
  12. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    take them back. but be sure your meter has a dated calibration sticker on it.
     
  13. Audioguru

    New Member

    Dec 20, 2007
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    I like the "resistors" that have a single black band. Their resistance is always extremely accurate.
     
  14. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    I'm sure there will be a lawyer looking to make a name for themselves will sue for false advertising.
     
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