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  1. J

    What should I look for in a breadboard to buy one?

    Breadboards are fairly cheap, so you can look in a lot of places. I have two. One I bought at radio shack for about $23, and another (twice as big as the one from Radio Shack) that I got from Jameco that was twice as big, and a few bucks less. Throw in a set of really nice jumper wires, and...
  2. J

    its been kind of .....DEAD lately...

    Sorry to hear about the cold. Here in Arkansas it is NICE. 63 degrees F today. Happy New year!
  3. J

    12 Key Matrix Encoded Keypad Question

    Does anybody have a good circuit diagram for how to hook up a matrix encoded keypad. It doesn't have to be 12 key, that's just what I have. If, say, you have one for a 16 key, I can extrapolate. I am trying to get this sucker breadboarded and it's driving me crazy. I's appreciate any help. Just...
  4. J

    I see the pic compiler flow chart basis

    I agree that systems which produce code are error prone and tend to have a bit too much trust put into with them (usually by the bean counters). You da man....
  5. J

    I see the pic compiler flow chart basis

    Actually, $690 is a lot to pay to program PICs, considering they only cost a few bucks each. Oh, wait, you were being sarcastic. That's so funny!
  6. J

    My first project

    I figured the 6-8V running into the 7805 in the picture should be more towards 8V than 6V :->. I've not worked with the LM2931. The most common type of +5VDC regulator I've seen is the 7805 (276-1770 from Radio Shack). But, like you said, the 7805 won't work with less than 7VDC input. The...
  7. J

    Voltage

    Nicely stated. My point exactly. It is a "difference." Which means its nature is inherently linear (and thus requires two points in space).
  8. J

    I see the pic compiler flow chart basis

    This looks interesting. Another "code without code" type of development system, right? I wonder how well it works...
  9. J

    My first project

    I'm with gogo2520 on this one. You should only need one battery to power the 7805 regulator, which will provide a steady 5V to your PIC. The output i/o pins on the PIC will provide the necessary voltage to drive the LEDs, right? Just make sure to put an appropriately sized resistor in series...
  10. J

    Cold Heat Soldering Tool

    I've heard that it takes a fair bit of pressure to activate the mechanism, which makes it difficult to use for some delicate operations.
  11. J

    Voltage

    You pose an interesting question. Is there a potential difference even if I don't measure it (by connecting a Voltmeter to two points in the circuit and measuring the difference between the two points)? I guess the answer, from a quantum mechanics standpoint would be, well, maybe. But, unless...
  12. J

    Making LEDs turn on at a certain resistance

    I don't know where the original came from, but I just selected the "
  13. J

    site is useless

    I think some people just like to start arguments... not a single reply from this guy to the responses to his allegations that this site is useless...
  14. J

    Voltage

    Voltage is not the number of electrons in a block of conductive material (nor the energy contained within them). It is a *potential* (as you mentioned) for those electrons to flow, which, by definition, means it MUST BE measured relative to some other point. Unless compared to some other...
  15. J

    difference between negative supply and ground???

    Oh great, audioguru, please lend us your wisdom and expand on your comments. An op am relies on differential voltage (so that it may amplify accordingly), but please explain how to supply a "negative" voltage to any given circuit (and what that means). This concept has eluded me as well. Thanks.
  16. J

    MAKE Magazine

    I've noticed that too. But not only that, it seems that the more rural areas have the least up-to-date satellite photos based on recent expansion in Little Rock that is not reflected in the photos, and comparing that to more urban areas like, say, the Atlanta metro area. And areas of forrest...
  17. J

    MAKE Magazine

    That's neat. And so is google Earth. I must have spent 4 hours the first night I installed it looking up the addresses of different people I know.
  18. J

    MAKE Magazine

    I requested and got the Digikey catalog one time in the mail. It was a little overwhelming. Thanks for the links. btw - AR is Arkansas, Arizona is AZ. It's a common mistake.
  19. J

    MAKE Magazine

    I appreciate the reply. I have only built one of the projects (Issue #2 - Mousebot), but had to get the parts from two different places because of price. I got the motors from Solarbotics, and everything else from Jameco. (Jameco didn't have motors small enough to fit in the mouse case.) So I...
  20. J

    Need help deciding on a multimeter

    I'm a fan of the Radio Shack 29 Function DMM. It does everything I need. But if you want a cheap Capacitance meter, Radio Shack has a 49 function DMM that supposedly checks  capacitance within a certain range. But if you want to go that far, get yourself a good LCR meter.
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