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  1. J

    Garage door open switch to Honeywell thermostat

    All you need to do is open circuit the thermostat control to the heater, but what exactly do you plan to use on the garage door to open circuit the thermostat control? ARe you planning on using an electrical signal or a mechanical switch to control that? What is a reed switch? edit: After...
  2. J

    Understanding stepper motors - parallel vs. series

    http://www.kelinginc.net/KL23H286-20-08B.pdf If both ways provide the same holding torque, then what would be the negatives of using series over parallel to reduce the current per phase which would also reduce heat in the driver? I am assuming that since the rated voltage and phase...
  3. J

    Surface mount heatsinks

    http://www.avayanelectronics.com/Products/AE-STPR8811/AE-MDL-STPR8811_Manual.pdf There is no specific instructions. Would it be unwise of me to use a heatsink that was glued to the top of the DRV8811 with thermal paste instead of this surface mount heatsink? From the datasheet I find it hard to...
  4. J

    led motion light

    when you take an VAC and rectify it, you must always multiply by 1.414 to get the full VDC. the equation is 12v * sqrt(2) == 12v * 1.414 http://www.play-hookey.com/ac_theory/ps_rectifiers.html You don't have both diodes forward biased at the same time do you? Can you draw us a schematic? or at...
  5. J

    Bridging a LM1875T

    http://en.wikipedia.org/wiki/Bridged_and_paralleled_amplifiers#Bridged_amplifier My guess is no http://lmgtfy.com/?q=lm1875+bridge
  6. J

    Questions about ELF. Can someone PLEASE help me!

    It seems to work so well it has deceived you from rational thought process.
  7. J

    Questions about ELF. Can someone PLEASE help me!

    Good luck with that oxymoron!!!
  8. J

    led motion light

    How many diodes are you using? Two would explain the 15Vdc, since only one dode is conducting on each pos/neg cycle of the AC. 12 * 1.414 = ~17V minus the diode voltage drop.
  9. J

    Surface mount heatsinks

    http://www.ohmite.com/catalog/pdf/d-sink.pdf How does one go about soldering these onto a pcb? My first thought was heating up the ends of the tin rods, but after looking at my boards, this is gonna be nearly impossible since I have surface mount devices within an 1/8th inch of those tin...
  10. J

    bridge rectifier project

    I don't think motors care as much about voltage as they do current. Dc fans in computers can be driven with a potentiometer at a wide range of voltages.
  11. J

    bridge rectifier project

    I thought any rectified AC signal is 1.414 more then the AC Vrms. Was unaware that you needed a capacitor for this to happen.
  12. J

    555 sequential timer circuit

    save your images as .gif's, this will allow for larger resolution photos with less overall size. If not post two pictures.
  13. J

    Sherlock Holmes - Why did the diode fry?

    You might want to double check the continuity of the bypass while your at it to make sure that is working as intended. Btw, how did you come up with comedic instead of cosmetic?
  14. J

    Need help please

    I think it has been discussed before, but running motors in series isn't the most sane idea. The way a motor acts it will cause one to spin faster then the other, both motors will need to handle twice their own current requirements as well. Those links you provided don't seem to make sense to...
  15. J

    Transmitter

    I had same thought, if it was a cell phone you seen someone use then they was doing it by bluetooth. Do a search on google.
  16. J

    Help with Leappad mains adaptor.

    The voltage is more important then the amperage rating, but that is not to say amperage is not important. You need a supply that will provide the right voltage with at least the minimum amount of current needed. Having extra current is not going to hurt anything as the device will only draw as...
  17. J

    Person needed to build a chess computer using our chess software

    Interesting idea, too bad I am unable to help.
  18. J

    Stupid question but.....help!

    I would opt for some quick disconnects. Solder two in parallel and then when you switch the batteries, the couple of seconds the new one is plugged in and the old one is removed would negate any bad effects, as even a battery needs time to heat up before it explodes. :) How long can it possible...
  19. J

    DC/DC Power Supply Help

    Seems the OP has no intention of explaining what he is really up to. I asked the same thing.
  20. J

    programming language to program hardware

    Since you can embed asm in C, my take is start out where it is easier for you. Normally this means a high level language. From there you can learn asm when you need it, then you can easily slide to all asm in the event you have to use it. Everybody thinks differently, you currently work as a...
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