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  1. KJ6EAD

    soldering small SMT resistors, capacitors and transistors, I can't get them flat

    I've had success reworking chip capacitors using hot tweezers and holding the component tight to the board with a pick.
  2. KJ6EAD

    LED Light Box Troubleshoot

    Where did you get this circuit design? What is the theory of operation?
  3. KJ6EAD

    soldering small SMT resistors, capacitors and transistors, I can't get them flat

    Hold the part down with the tips of your tweezers or a pick while tacking. Dry tack. Wet tack. Bump tack.
  4. KJ6EAD

    what every good moderator needs ;)

    Clever. I see you have the high-strength nutter immobilizer.
  5. KJ6EAD

    Circuit design procedure

    Starting with episode #221, David Jones has been going through the design process in some detail for a lab power supply on his EEVBlog. http://www.eevblog.com/
  6. KJ6EAD

    Nuclear Plant help

    By the way, I'm not just some guy looking stuff up on Wikipedia. I used to make the moderator tubing that surrounds the fuel pellets in fuel rods.
  7. KJ6EAD

    What is with these kids today?

    I'm very good at ignoring requests for help that have elusive titles, bad or incomplete problem statements, txt spk or smell like homework. I have been collecting all their "thanks in advance" without helping. :D My favorites are the ones that start all humble like "I'm a noob and know...
  8. KJ6EAD

    Nuclear Plant help

    Not really. Nuclear fuel rods in a light water reactor are not just fancy immersion heaters. Read or at least skim the Wikipedia article. Here's a little sample: "Heat generation The reactor core generates heat in a number of ways: * The kinetic energy of fission products is converted to...
  9. KJ6EAD

    Nuclear Plant help

    http://en.m.wikipedia.org/wiki/Nuclear_reactor#_
  10. KJ6EAD

    circuit board testing ?

    You need to do the same kind of test as before on another large bridge rectifier (BR3), a small round one (BR2) and a voltage regulator (U4).
  11. KJ6EAD

    Problem with test wiring for DIY ipad dock

    You probably need to put some voltage on USB pins 2 & 3. http://www.ladyada.net/make/mintyboost/icharge.html
  12. KJ6EAD

    MAKE: Electronics Ex. 10 Help Needed

    I don't know what Ametron has in stock. Why don't you ask THEM.
  13. KJ6EAD

    circuit board testing ?

    Yes. The same area covered in photo six in the first set of ten. It just needs better light and focus at the board level. There's a three-terminal device in a TO-220 package and what look like two bridge rectifiers that I'd like to identify.
  14. KJ6EAD

    HelpAChinaMan.com

    This is a bad idea. http://www.moviewavs.com/php/sounds/?id=gog&media=WAVS&type=Movies&movie=Office_Space&quote=worstidea.txt&file=worstidea.wav
  15. KJ6EAD

    buss fuses

    Oh, yeah. They very well may be. If that's the case, disregard my prior admonition.
  16. KJ6EAD

    buss fuses

    You can't safely use a 32V fuse but you could use a 125V if you see one. Usually they're 32V or 250V. What type/size are you trying to replace?
  17. KJ6EAD

    circuit board testing ?

    There are a few more components to check but I can't read the identifiers on the silkscreen so I'll have to download one of your photos and draw circles around them.
  18. KJ6EAD

    circuit board testing ?

    I've been reviewing some of our earlier results. Can you unsolder the SCR and test it again out of circuit?
  19. KJ6EAD

    circuit board testing ?

    I don't like the reading on D5 but it could be an in circuit effect. Can you unsolder and lift one lead to isolate it and test again?
  20. KJ6EAD

    circuit board testing ?

    And another optocoupler (Sharp PC817), U6 pins 3 & 4.
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