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  1. J

    transformer from a UPS

    If it was a APC UPS you might drop them a note and ask them, they have been very helpful in the past in giving me information about transformers I have salvaged from their equipment.  Jim
  2. J

    16 or 24 Cannel Gang Switch

    I am assuming that MCU programming isn't what you do everyday so I suggest you take a look at a Basic STAMP or a PICAXE chip.  Through relatively minor programming you can accomplish what you are after. Jim
  3. J

    Switch operated on cellular reception

    Try searching on cell phone remote control adn you will find all kinds of hits. Jim
  4. J

    12 Volt to 220 Volt Inverter 500W

    I'm gonna ask everyone what may be a really dumb question; can I run this backwards.  In other words, connect the 220VAC and expect to get regulated 12 VDC out the other side at fairly high amperage? Jim
  5. J

    My 12 watt x2 stereo amplifier

    Good for you!  Looks nice and professional. Jim
  6. J

    120VAC to a2VDC 30A power supply circuit needed

    Thanks Guys. I don't pretend to understand how you  get from 19 VAC to 24VDC through rectification but will assume that to be true.  Modifying the transformer is really not a practical possibility.  These transformers are from UPSs so I am wondering how they do it; they provide the power to...
  7. J

    120VAC to a2VDC 30A power supply circuit needed

    120VAC to 12VDC 25A power supply circuit needed
  8. J

    VERY nub need some help on a project

    Try allied Electronics, www.alliedelec.com , they have about a million waterproof boxes in all kinds of sizes and shapes. Jim
  9. J

    Voltage Level shifting

    Try Googling 7805 voltage regulator.  This device with a few caps will control the output.  There are about a million circuits out there using it as it is very common. Jim
  10. J

    please help make a variable power supply

    The power supply will supply amerage up to it's rated amount automatically.  Amerage output is determined by the "draw" of the components or circuits that are using the power supply. Jim
  11. J

    Driving 740 LEDs with variable intensity

    I'm sorry, I'm a dummy sometimes; I forgot to include the link. http://stores.ebay.com/PHAnderson-Electronics He also has a store outside of ebay, I think. Jim
  12. J

    Driving 740 LEDs with variable intensity

    Basil, You might want to take a look at the stuff this guy sells related to PICAXE.  He has chips but, more importantly, he has prototyping boards that have a serial hookup and power supply on them so all you have to do is plug in the chip and program it.  I have bought several things from him...
  13. J

    Driving 740 LEDs with variable intensity

    I fool around with BASIC Stamps too but discovered PICAXE chips the other day and think you might want to look at them for your application.  They are SOOOOOooooo much cheaper and can be programmed using Basic.  Jim
  14. J

    Driving 740 LEDs with variable intensity

    I think the next thing she ought to be buying is about 100 8 position SIP resistors! Jim
  15. J

    white led

    I have been following this thread to see the outcome.  One thing, based on th elast drawing, that should be noted is that you are not working with 20 LED/resistor combinations in series, you are working with 20 LED/resistor combinations in parallel so you might want to rework the numbers a...
  16. J

    white led

    Plus, what is the current draw of the LED's you are using, there are a lot of different LED's out there. Jim
  17. J

    help "EtCHING technique"

    Take a look at the group linked below.  You will have to join but it is free and they don't bury yoou in spam. http://tech.groups.yahoo.com/group/Homebrew_PCBs/ Jim
  18. J

    Temperature display with ICL7107CPL

    I'm not sure you will need any caps if you are using a battery for your supply.  Perhaps others will have a comment on this. Jim
  19. J

    Highside mosfet gate spike

    Try putting a diode across the MOSFET to direct the bounce when the motor direction (polarity) changes.  Remember, the motor is just a big inductor and the change built up in it comes bouncing back when the current drops. Jim
  20. J

    Variable Power Supply

    Good for you.  Do a Google search on LM317.  This si a voltage regulator that is perfect for what you want to do.  The datasheet has some good examples in it, as I recall.  You will find a lot of hits for this part as it is fairly common. Jim
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