So how many parts did you fry on your first couple of projects?

Discussion in 'General Electronics Chat' started by spinnaker, Feb 6, 2010.

  1. spinnaker

    Thread Starter AAC Fanatic!

    Oct 29, 2009
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    Just got back into building projects after about a 25 year break.

    I'm trying to build a power supply as my first project. So far I have gone through 3 PICs and 3 LCDs.

    Each time after it happened, I realized how stupid the mistake was.

    Has anyone else had this bad luck in their first couple of projects?

    Please tell me things will get better. :)
     
  2. blueroomelectronics

    AAC Fanatic!

    Jul 22, 2007
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    Why does your power supply need a PIC & LCD? Where did you get the schematic?
     
  3. n9352527

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    Oct 14, 2005
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    Must be one with digital voltage and current meter.

    I destroyed a few transistors and ICs, nothing too expensive. However I did manage to blew up a TV once, in an effort to repair it :D
     
  4. JDT

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    Feb 12, 2009
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    Things will (probably) get better.
     
  5. Art

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    Sep 10, 2007
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    I just wrecked a pic programmer kit. I really shouldn't have. I've built about three that went ok, and countless other projects.

    I wrecked the most stuff trying plans for things off the net that I didn't really understand.
    Maybe this caused me to substitute parts I shouldn't have or something like that.

    Going back even further, one of my first (if not my first) kit never worked
    (a two transistor radio). Later I had a couple fo crystal radio kits that both worked well though :)
     
  6. spinnaker

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    Because I wanted one. :) Actually, I thought it would be a good learning experience. My next project is planned to be a solar panel / light project controlled by a PIC. Thought this would be good experience and it was.

    Got the PS schematic here and modified it. Everything was turning out very nicely. It is not the design it was stupid mistakes made, working when I was tired and should have put ti away for the night. In fact both mistakes made last night were just that, which really makes me made.

    The first PIC / LCD pair Ill, chalk up to inexperience. But the two last night was just a plain dumb mistake, which makes me angry. :)
     
  7. spinnaker

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    Yikes! I guess it could be worse. ;) Actually when I fried the chips this time I was worried I blew the programmer too. But so far it looks fine. I have a demo board that I need to test.
     
  8. Wendy

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    Mar 24, 2008
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    I'm not sure, let me check the brand on my thumb.

    Yep, fried a 2N2219A for sure.

    Basically when I started out it was transistors, lots and lots of transistors, with an occasional IC (555, 741, 7400 series chippie) thrown in.

    Did you know when a transistor is scorching hot it will leave a reverse impression of the markings on whatever flesh you are dumb enough to touch it to?
     
  9. Art

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    Sep 10, 2007
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    Lol, but could the brand really last that long?

    While we're going there... who picked up the soldering iron by the shaft thinking it was turned off
    and got that welt across the palm of their right hand? :D
     
  10. Wendy

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    Mar 24, 2008
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    Uhh, yeah, that would be me, working on my first VOM kit, looking at the kit thinking where I was gonna solder next and not looking at my hand. Only it was my thumb and forefinger. I remember the bubbling when I did it (ouch).

    That brand has since been overwritten by many others. It's a miracle I have any fingerprints left.
     
  11. spinnaker

    Thread Starter AAC Fanatic!

    Oct 29, 2009
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    That is hilarious! :):):)

    Thanks you guys are making me feel better. Keep the war stories coming.

    I guess what really frosts me is I am out of PICs and will now need to wait till they come in. And we are snowed in. I can't even get out to buy my brake and some sheet metal to start on my enclosure.

    No telling when my shipment will get here with all this mess.


    Oh well I guess that means I now have time for other projects like, varnishing the hatch boards for my boat. Or maybe cleaning the house.


    The amazing thing is that my DTV dish is filled with snow yet I am still getting a feed. I am trying to avoid going back out in the yard to clear it.:mad:. No I don't think so, sounds like a good weekend for naps. :)
     
  12. VoodooMojo

    Active Member

    Nov 28, 2009
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    oh, that's right...
    the Steelers are NOT in the Superbowl!!!!
    tsk, tsk...it IS a good time to nap...
    maybe next year..
     
  13. VoodooMojo

    Active Member

    Nov 28, 2009
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    seriously,
    this just happened a few days ago...
    too many wires and messy housekeeping made me cross a couple wires and it lowered the top on this diode. 1N4004

    it was so neat that I cut another diode in half and video taped it with the hand held microscope.
    It is surprizing how bright the light is just before the smoke fills the lens.
     
  14. blueroomelectronics

    AAC Fanatic!

    Jul 22, 2007
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    Sorry just had to say gotta love schematics where the author puts his face in em.
    [​IMG]
    Not sure why his head is the mains supply...
     
  15. spinnaker

    Thread Starter AAC Fanatic!

    Oct 29, 2009
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    Yeah I thought that was hilarious too. :)
     
  16. Element1

    New Member

    Feb 6, 2010
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    I fried 3 CRT TV's when I built my moded Xbox arcade when trying to hook up the modified sound system.
     
  17. VoodooMojo

    Active Member

    Nov 28, 2009
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    Quotes:
    "Sorry just had to say gotta love schematics where the author puts his face in em."
    and
    "Yeah I thought that was hilarious too. :)"

    hey brothers,
    you are making fun of one of "our own";)

    (no it's not me....)
     
  18. bluebrakes

    Active Member

    Oct 17, 2009
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    i'm guilty of silly mistakes...

    I'll spend hours on designing a pcb, checked it, double checked it. then i'll make it only to find that it blows up. why? because i mistakenly reversed some of the pins on an IDC socket or something.

    So i'm very guilty of making petty mistakes that usually ends up in smoke.
     
  19. BMorse

    Senior Member

    Sep 26, 2009
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    I have done my share of letting out the "blue smoke" out of some IC's..... here was one of my more memorable moments.... and it was even cought on video, so I left it in for laughs.... at around 0:43 seconds into the video, I was testing interrupt routines on my Pic32 development board when I touched the input to Vcc instead of ground, you can see a flash of light as a diode burned up, lol..... >> http://www.youtube.com/watch?v=32j9wORr2_k this was during the Microchip Design Challenge competition....:eek:
     
  20. SgtWookie

    Expert

    Jul 17, 2007
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    Fooling around a few months back, I managed to reverse the power and ground connections to an LM324 quad opamp on my breadboard.

    It made the prettiest jet of blue flame from the side of the package near the Vcc or GND pin; sort of like a jet engine with afterburners engaged. :eek:

    This did not-so-good things to the breadboard, which is a large and rather expensive 3M model; however it seems to just be surface discoloration and not permanent damage.

    It was one of those forehead-slapper kind of things. :rolleyes:

    I'd reoriented the breadboard numerous times trying to follow a schematic I'd thrown together in haste; and simply confused the Vcc/ground leads. It's an easy mistake to make.

    Check things over three times before you apply power. Checking things twice might not be enough; it's easy to make the same mistake twice. It helps a lot to ask someone else to look things over, as the problem/circuit is new to them, and they may see things that you completely missed - because you were overly familiar with the problem/circuit.

    If you're tired or frustrated, set your project aside for a time when you're refreshed. Enthusiasm is a good thing, but trying to go too fast (particularly when you're new) can quickly lead to disaster.

    In the supply schematic you're using, there is no "default" resistor from point C to ground. I see that as an un-good thing.

    Also, there are no resistors on the bases of the transistors. If you try to drive that circuit directly with a PIC, you will fry the I/O pins.

    The switch is shown on one side of the primary, yet the fuse is on the other side. This is not good. The fuse should be before the switch on the HOT side, and the low side of the primary should be connected to NEUTRAL.
     
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