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  1. KJ6EAD

    Need help with implementing electronic die features please

    Take a look at how the Velleman MK152 is clocked. It spins down slowly then stops and fades to black after a delay. http://www.vellemanusa.com/downloads/0/minikits/manuals/manual_mk152.pdf Here's my short video of the MK152 in operation.
  2. KJ6EAD

    how can i find led specs

    You can set up a 20mA constant current source and measure the Vf. If you've got a 20 - 30 Volt supply, you can run several LEDs together in a series string on a breadboard to measure them. Be sure you have a 20mA current then measure the individual voltage drops.
  3. KJ6EAD

    help me make led lamp like this

    9.6V, (2 X 3.3V + 3V headroom).
  4. KJ6EAD

    help me make led lamp like this

    Use an LM317LZ in constant current configuration to drive each series string of 2 LEDs. Use a 68Ω resistor as the control for the LM317. The schematic is in the datasheet.
  5. KJ6EAD

    lights synchronized with music

    For color organ type applications it's best not to have the filter Q too high to avoid dead gaps between bands.
  6. KJ6EAD

    556 clock problem

    Both. See page 10 of the 555 datasheet under "Additional Information".
  7. KJ6EAD

    James Bond CIA Gadget Challenge

    Your friend will win because he'll require you to build and demonstrate the lethality of the device to prove it works.
  8. KJ6EAD

    556 clock problem

    The supply is on pin 14, not 1 and it's 5V. The 556 is not designed to operate from a supply less than 4.5V. The configuration shown in your fuzzy picture is a typical astable for a 555. You need to look at the data sheet (link below) for the 556 to get the pin numbers straight. Two 4.7k...
  9. KJ6EAD

    556 clock problem

    What voltage divider? There usually isn't one in this type of circuit. Are you referring to the charge/discharge timing resistors? Show your schematic.
  10. KJ6EAD

    minimising cb radio

    The longer wavelengths of CB are more readily attenuated by the building and the shorter wavelengths used for mobile phones penetrate the various spaces between attenuating materials better. The wavelength of CB is something like 37 times longer than mobile phone wavelengths, about like the...
  11. KJ6EAD

    Replace Switch on circuit board question

    I've drawn you a picture, two actually.
  12. KJ6EAD

    LED Light Box Troubleshoot

    Tangible results and the realization that you've expanded your knowledge and skills beyond previously assumed limits should be a sufficient pride preserver. Post a link here to a short video of your completed project if you can when it's done.
  13. KJ6EAD

    LED Light Box Troubleshoot

    The light ones are the more modern switch mode power supplies. They are more efficient and usually well-regulated so use that. The older electromagnetic power supplies will often run several Volts above their nominal rating when lightly loaded which could shorten the life of your LEDs.
  14. KJ6EAD

    LED Light Box Troubleshoot

    Yes, as long as the 12V supply is reasonably well-regulated. Is it light and sort of flat or squarish and heavy? You will now be hit on... er... receive 86 friend requests from nerds.
  15. KJ6EAD

    LED Light Box Troubleshoot

    That's exactly how they're wired, small bused sections. They were originally designed to be installed as backlights in signage as a replacement for neon so they had to be easily field configurable by installers on ladders and bucket lifts. You're right but the MK103 and the MK186 both use a...
  16. KJ6EAD

    LED Light Box Troubleshoot

    Don't bother. Use the MK186. See my edited post above.
  17. KJ6EAD

    LED Light Box Troubleshoot

    Velleman MK186. http://www.vellemanusa.com/products/view/?id=525680
  18. KJ6EAD

    LED Light Box Troubleshoot

    I'd advise you to use a real sound to light circuit design and stay far away from "destructables". You're risking serious damage to your stereo, MP3 player or whatever you're using to light up a few LEDs. I see the writer of that destructable hasn't responded to you or anyone else having...
  19. KJ6EAD

    soldering small SMT resistors, capacitors and transistors, I can't get them flat

    The videos I linked previously SHOW correct methods. Here are more: Hot tweezer component removal. 0402 installation. 0603 installation. 0805 installation. 1206 installation.
  20. KJ6EAD

    electonics quiz. cant figure this out can you guys help

    No, because you have to do your own homework to learn.
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