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  1. J

    Huge trouble driving a stepper motor with an h-bridge

    it doesn't look it, enlarge that schematic and post another picture.
  2. J

    Which online portal is best for buying electroincs?

    where are you located? The best distributor to use is the one closet that has what you want would be my guess. If you are in europe, you can only have RoHS compliant components shipped in. Places in the US might have a much more limited supply while a company in the UK would only sell compliant...
  3. J

    Huge trouble driving a stepper motor with an h-bridge

    were you using logic level mosfets? What was the voltage applied to the source/gate of the p-channel mosfet? From the schematic it looks like your p-channel mosfets are wired wrong. You need the gate to be more negative then the source for a p-channel to turn on yet you have the source...
  4. J

    Watch project for the blind

    Church? it always gets over the same time. Not sure why you would want to check the time. I am sure a library would make an exception for a blind person. Not sure what a blind person would do in a library, but ok.
  5. J

    New to this forum

    Audio you say? Have you ever visited diyaudio.com? I personally have a fascination with that site myself. I had to step away though, I was spending way too much money on kits. Like a few grand too much...
  6. J

    Which Dev Board to Buy?

    it was on ebay, you can search for sellers from certain countries. It should help you find a cheap supplier in china to buy one from. ebay has some awesome search capabilities, try them out and you will find exactly what you want for the right price. I have no idea if the seller I bought mine...
  7. J

    I am trying to save on my electric bill

    totally agree, but I hate cleaning windows. Can't see myself ever cleaning my solar panels with the amount of dirt you find in most rural areas.
  8. J

    Bridge Rectifier Help

    They rate transformers in VA because transformers don't theoretically use any power because the voltage and current are out of phase with each other. But, you figure it the same way you figure power. V * I I just doubled the current requirements and @ 24VDC that came out to ~8VA added a little...
  9. J

    Anyone know how this works?

    I think the input would the 220 in the front. Last I knew the only country that had 120VAC was the USA. The fact that it is made with korean on the front would tell me it was meant to be used in korea. It is kinda confusing
  10. J

    Bridge Rectifier Help

    2. 10VA should do it. I figured it out for 350mA, but depends on your current requirements under load. 3. 1000 - 3300uF should be more then sufficient and rather cheap at 24VDC
  11. J

    I am trying to save on my electric bill

    You need to be careful about this though. I had some people question me over something like solar power. Needless to say where I live, you would barely pay back the initial cost of a solar system before you died. I say that because the sun's power is not the same in all places on this earth. I...
  12. J

    Holding a JK Stable at Startup

    an RC circuit on the input?
  13. J

    Watch project for the blind

    so how are these pulses generated? Is there like a way to active the sequence? How will the user tell the difference between a stop and start of a sequence of pulses? I guess what I am having a hard time understanding is how the user will feel all four of the pulses at the same time and manage...
  14. J

    CDMA

    I think his question is still very valid. The code is analogous to the different languages, but how does the receiver know to distinguish between the codes? More or less if I was in a room with 10 different people speaking 10 different languages all at the same time. I would find it hard to...
  15. J

    Op Amp Slew Rate and Open Loop Frequency Response

    I don't dare to try and explain it very well, as my understanding may not be the best. But you might get better results in your research if you substituted freq for bandwidth.
  16. J

    Short on a psu LS1904006A

    it is a resistance tester that uses high voltages to test against insulation failures. In almost the exact same way as a MM works, except the megger will output +500VDC to break down weak insulation.
  17. J

    basic electronincs

    Yeah I actually downloaded the file myself. But I would really like a copy, but at over $100 dollars I am not to enthused. Seems if you can find an english version that was not meant to be sold in the USA it cost about half price, part of the reason I can't find myself paying the high price...
  18. J

    Short on a psu LS1904006A

    Man you could have totally used my megger tester. :) If you had one, you could test the other coil and it would answer your question.
  19. J

    Need help building a proportional circuit for my RC Tank

    But that design you just posted will not work the way you want it to. There is nothing variable about the design. You need to have some form of logic to do what you want. The easiest way is to use a microcontroller to wait for a specific condition and then act upon that condition accordingly...
  20. J

    Polarity tester for 9 core cable

    then wouldn't a continuity tester be ideal? take another male and female connector and wire them 1 - 1 through 9 - 9. if the cables match up correctly it would light the LED because the circuit was complete. I don't get the polarity issue...
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