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  1. audioguru2

    500W_inveter

    Hi Ren, The Mosfets operate linearly in that sine-wave inverter. Therefore they get hot. Really hot. The inverter's efficiency isn't good. 200W in for 100W out. It doesn't need the frequency accuracy from an old MM5369 to make a crystal oscillator, any square-wave 50Hz or 60Hz oscillator will...
  2. audioguru2

    need a circuit diagram

    Is that TV so old or poor quality that it doesn't even have a tuner? You could take the tuner and modulator from an old VCR. You won't like the poor picture quality. A TV with an s-video input provides a much better picture.
  3. audioguru2

    Flyback driver experiments

    Yeah, more and more torches are made with special LEDs that operate at 5W. In the past month, the price for high power LEDs dropped to half, and in March a new one will be announced and their prices will drop again. Their battery lasts much longer than a torch with a globe that wastes 90% of its...
  4. audioguru2

    Adapting a 220V transformer to 240V?

    Hi Zeppelin, The voltage difference is less than 10% so I don't think there will be a problem. If you are worried about it, you could add a 20V transformer in series with its primary, wired in the opposite polarity to reduce its voltage to 220V. I thought England changed their mains voltage to...
  5. audioguru2

    Flyback driver experiments

    My ultra-bright LEDs light me up pretty well, but I think 1 million volts will light me up better.
  6. audioguru2

    0-30 Vdc Stabilized Power Supply

    You can use two 1 ohm/5W resistors in parallel, or two 0.22 ohm/5W resistors in series. Ten 4.7 ohm/1W resistors in parallel and many other combinations.
  7. audioguru2

    Flyback driver experiments

    Man! 1 million volts is a lotta volts.
  8. audioguru2

    Need help in using Darlington Pair IC ULN2003A

    You forgot to say what is going wrong. You forgot to attach a schematic of how they are connected together. You forgot to say the current drain or resistance of the relay coils, and the power supply's current capability. Did you forget to connect the ULN2003A COM pin 9 to the relays' +6V supply...
  9. audioguru2

    0-30 Vdc Stabilized Power Supply

    Can't you buy resistors with 5% tolerance? Is there only one reasistor value you can't find? Which one in the circuit?
  10. audioguru2

    capcitive touch sensor

    You still didn't include a link to the project you are talking about. On the projects index page, right-click on its English version and left-click Copy Shortcut. Then left-click in your reply and right-click Paste.
  11. audioguru2

    0-30 Vdc Stabilized Power Supply

    The voltage adjust pot is P1 and the current adjust pot is P2. Pots are made with a 20% tolerance so if their values are 20% low then the voltage or current max will be 20% high unless a trimpot (small preset pot) is added in series to increase the total resistance to the correct value.
  12. audioguru2

    need a circuit diagram

    You're going to make a TV transmitter? You're going to make a TV?
  13. audioguru2

    Switching polarity of motor

    There will be a huge current surge and mechanical jolt if the motor's direction is changed suddenly. It is best to stop the motor before reversing it.
  14. audioguru2

    Digital radar speedometer

    Here's the other one:
  15. audioguru2

    data sheets for BC337,1N4002..ETC

    www.datasheetcatalog.com is the 2nd one on my list. I think I found an old Sanyo hybrid audio amp there. It had hundreds of Watts of output and I wonder if they made any.
  16. audioguru2

    Flyback driver experiments

    I can picture millions of people flying to work in those things, with their hair standing up from the high voltage and their HV wires all tangled up! ;D
  17. audioguru2

    data sheets for BC337,1N4002..ETC

    www.datasheet.com doesn't work.
  18. audioguru2

    capcitive touch sensor

    Hi Ksp, You didn't provide a link to the project so I guess it is this Touch Switch one: http://www.electronics-lab.com/projects/sensors/002/index.html It doesn't have a schematic, just a pcb layout drawing. The text explains about how its flip-flop works pretty well.
  19. audioguru2

    data sheets for BC337,1N4002..ETC

    I go to www.google.com sometimes for datasheets for transistors and ICs but mostly to www.datasheetarchive.com for nearly everything. I go to www.digikey.com to find capacitors and resistors and use Digikey's links to the manufacturers where they have datasheets.
  20. audioguru2

    0-30 Vdc Stabilized Power Supply

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