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  1. J

    New Member

    posting replies should be allowed as long as you have an account. Welcome!
  2. J

    Experiment 9; MAKE: Electronics

    Looks it to me as long as he is hooking up the battery correctly to the breadboard. But his picture doesn't show that. Rleo, has the most promising idea for him. Measuring the resistance across component junctions will let him know if his circuit has any possibility of working. Alfa, if he...
  3. J

    Help to Design EGR Valve Simulator- Cheater

    Well getting the circuit to wait 1-2 mins before activating is not very hard either. I wouldn't let that slow you down.
  4. J

    Making your own parts on eaglecad and using I2C

  5. J

    Making your own parts on eaglecad and using I2C

    I don't use eagle exactly, but in KiCad it is pretty easy. I doubt there is really much difference. You open the footprint model for the 26pin model and modify it to have 28 pins then save as and it should be available for selection. Have you checked youtube for any videos? I always seem to...
  6. J

    C programming on PIC16F877A

    If you blink and LED too fast it will appear as always on. I would suggest a 500mS delay to start with. You should be able to see a half second blink rate. Steve brings up a good point in his post. I tried to stay away from that atm, but here is a couple good articles that do a really good job...
  7. J

    C programming on PIC16F877A

    I also thought in the newest versions of Hi-tech compiler pic.h was replaced by htc.h, but I am unsure since I don't really use PICC very much
  8. J

    C programming on PIC16F877A

    I am curious as to why you would ask that? Is the output different? Have you tried running that code with real components to see? Above all else, you should know this answer. :) If you are looking for a straight answer you are not gonna get it from me. That is how you learn by answering your...
  9. J

    C programming on PIC16F877A

    That makes no sense(because you fail to tell us or show us what your ports are set as input/output) and you don't tell us what you expect from this code. I can't seem to understand why you keep asking the same question? There is nothing right about your question because it is barely a question...
  10. J

    problem with tip122 at high volt

    I don't know what is going on, what mode are you using to drive the motor? Is the code something you wrote?
  11. J

    problem with tip122 at high volt

    3A per phase. If I understand you it seems like both phases are energized at the same time. Do you have a schematic of the driver?
  12. J

    problem with tip122 at high volt

    I am finding it hard to understand why you need to limit the current? If you run the motor at its max current then you won't need a limit.
  13. J

    problem with tip122 at high volt

    You should be running the motor at its rated current. Otherwise at low voltages your max speed will suffer. AFAIK steppers are constant current devices or as close as possible to constant. They will work hard to try and maintain a constant current.
  14. J

    Hello Im new this is my first post, I have lots a questions.

    I am very fond of diyaudio.com if you are into do it yourself amplifier kits. When I used to visit their frequently they used to always be running bulk PCB sales/kits. Someone makes a really good design and so someone else decides to make a PCB and get it massed produce. The best part, it comes...
  15. J

    Which Dev Board to Buy?

    That is cheap for a 2650, but I never bought anything from digikey that took two weeks to get. I live in PA and receive my stuff on the order of 2 days. I have placed 3 - 4 orders and never waited more then 3 days. Their shipping is tops
  16. J

    Hello Im new this is my first post, I have lots a questions.

    I don't think pre-amps are meant to drive loud speakers, that is why they are called pre-amps and not amps. But, anyway, good work and now on to bigger things I presume?
  17. J

    C programming on PIC16F877A

    Well it clearly looks to me as though it is defining RA1 as PORTA bit 1. So that should answer your above question.
  18. J

    what happens if emitter-base & base-collector junctions are forward biased with 0.7V?

    Didn't you read that thread I linked you to? Seeing as how you have two PN junctions together but in opposite directions I don't think both junctions will be forward biased. In saturation mode, the voltage drop across the C-E junction is the resistance * current. The current will be the Hfe *...
  19. J

    does a 9V battery have a current limit?

    How come no one ever listens to me? Did I not say to measure the battery voltage with no load? Did I not say the battery has an internal resistance? I will just stop wasting my time I suppose.
  20. J

    does a 9V battery have a current limit?

    If you don't want your LED going 'poof the magic dragon' you won't try it till you get a heat sink though.
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