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  1. KJ6EAD

    led lamp assembly help

    I'd suggest doing two things: first, draw out the circuit traces for a segment of the PCB to determine the actual topology and second, use the diode test feature on a meter to verify the correct polarity of one of the LEDs within that topology to extrapolate the correct polarity for the circuit...
  2. KJ6EAD

    led lamp assembly help

    Your pictures aren't clear enough to be sure but with one 75Ω resistor per six LEDs, the supply would need to be ~24V to provide a useful current level. The situation you described where an LED glowed and then died is typical of a reverse polarity overcurrent failure event. Do you have or can...
  3. KJ6EAD

    Name that switch!

    Here's the patent. https://www.google.com/patents/US4976618 There are many subsequent patents that cite it. There was a lot of research and product development that followed Kent's work which may have resulted in some other products that were simpler, cheaper or more effective. He put all of...
  4. KJ6EAD

    Name that switch!

    That's essentially what the Oral Sensor biofeedback device developed by Kent Anderson (Cycura Corp.) did. There was a molded appliance that acted as the pressure bulb and the feedback was audio. My brother worked on it's development. It was patented and FDA approved but it's no longer on the market.
  5. KJ6EAD

    I bought this at a flea market, not entirely sure what it is, help?

    What it is is DANGEROUS in your hands. I hope for your sake and that of everyone nearby, it doesn't work. Don't attach it to any power source. http://en.m.wikipedia.org/wiki/Laser_safety It's a 30mW infrared laser for fiberoptic transmission of data. Here's a data sheet for a similar model...
  6. KJ6EAD

    Looking for receptacle lube

    In addition to Hop's suggestions above, all of the following will work: dielectric grease from any electrical supplier is pretty optimal; O-ring grease from an industrial supply or auto parts store; plumber's grease (an O-ring grease) from a plumbing supply house or home improvement store; food...
  7. KJ6EAD

    Missing cord, irregular size, help?

    Your example from Amazon looks perfectly adequate except for the 2' length. I'm not sure why you think it's incorrect. Radio Shack lists several as expected, including 6100410 which is 6' long and white, but since their website sucks and no one in the store knows anything about anything...
  8. KJ6EAD

    Missing cord, irregular size, help?

    Any place that sells or services anything electronic will have them, including thrift stores for a dollar or two.
  9. KJ6EAD

    Running incandescent or halogen bulb with 2/3 or lower voltage possible?

    Don't worry too much about eye damage. An incoherent source of relatively broad spectrum such as incandescent or halogen lamps will be too hot or bright in obvious ways before they're dangerous in unseen ways. Have you tried two 20W, 12V halogen lamps in series on a 12V supply for effect. By...
  10. KJ6EAD

    Help to identify a volume knob

    Nice find. If it's a dimensional fit, it'll probably work unless the problem lies somewhere else.
  11. KJ6EAD

    Help to identify a volume knob

    These are encoders with tactile switches. This is probably the brand and basic model used but all parameters must be specified to order as they were by the manufacturer of your car stereo. As Dave said, the stereo manufacturer is your easiest source if they'll support component level repair...
  12. KJ6EAD

    Running incandescent or halogen bulb with 2/3 or lower voltage possible?

    Probably a thinner, shorter filament than is typical to save on tungsten.
  13. KJ6EAD

    Panasonic Earbud Repair

    I've posted on this topic somewhere before, either on this forum or another. If you Google "litz+KJ6EAD+headphone", you should find some relevant information. Do you have good soldering skills and adequate equipment?
  14. KJ6EAD

    Mobile phone chargers

    The most difficult ones may have some intelligence inside that will prevent you from using them as a simple voltage supply without modification, modification that's only worth attempting for educational purposes. If you run across one that has a third wire, it may be a voltage sense line and...
  15. KJ6EAD

    Mobile phone chargers

    If the charger has a USB connector, then by convention it must output 5V at a minimum of 500mA. It may output a higher current but it may only do so in negotiation with the charged device. Most of them seem to have a 1A rating on the label but I've not needed more than 500mA for any of my...
  16. KJ6EAD

    Salt lamps - what effect would the salt have on the light from incandescent bulb

    There is no elemental iron, only compounds thereof. These compounds filter out the small portion of the light from the incandescent source that are higher frequency wavelengths such as purple, blue and green, converting them to thermal energy mostly in the longwave IR spectrum.
  17. KJ6EAD

    Whack-a-mole

    Here's the old thread on this very forum where the same thing was discussed. See if that answers your question. https://www.electronicspoint.com/threads/electronic-whack-a-mole.254398/
  18. KJ6EAD

    Salt lamps - what effect would the salt have on the light from incandescent bulb

    Pure salt will tend to yellow the light a bit but since your incandescent source is rich in those wavelengths without filtration it may not be noticeable. The typical salt specimens used for lights have some iron compounds in them which will naturally filter to orange and rusty red.
  19. KJ6EAD

    Supercapacitor Based 5 minutes Fast USB Charger

    His post is titled "Supercapacitor Based 5 minutes Fast USB Charger" and his video is titled "How To Charge Your Phone in 5 Minutes…" What nuance of opposite meaning am I missing?
  20. KJ6EAD

    Toggle Switch Covers

    This is a joke, right? Even before the bankruptcy, an inquiry of this sort would be met with a blank stare or the telephonic equivalent. The parts you're looking for are called "vinyl switch caps". Most manufacturers of miniature toggle switches offer them, C & K for example. You'll probably...
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