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  1. dave9

    Jumper wire

    Odds are that you have something old, now unused that you can get the wire from, whether it is solid core bell wire or ethernet cable, multi-strand extension cord or appliance wire, enamelled copper windings off an old transformer, etc. I mean if you so seldom use wire that you have to buy some...
  2. dave9

    Zener Voltage Regulator to power Arduino

    I think Bluejets means to only have the USB hooked up to it, not that PSU during programming.
  3. dave9

    Capacitor Substitution

    I'd check for bad solder joints, particularly anywhere discolored from heat like those resistors you mentioned (and the transistors on the heatsink), reflow the solder just to rule it out. I'd also look very closely at the copper traces there to see if they are lifting off the PCB... your pic...
  4. dave9

    Question evaporate acids and corrosion electronics

    There is something lacking in your life to have this strange obsession with electronic degradation from common household cleaners, humidity, or other factors you have posted about previously. You need some deep introspection about why you value mere electronic items so dearly and why you are so...
  5. dave9

    Question evaporate acids and corrosion electronics

    Considering all these questions about death and decay that nobody else has to be concerned about, I am convinced you should get rid of your electronics. Too Much Work And Worry. If these fumes are not causing you severe respiratory distress, they are not at a level remotely close to harmful to...
  6. dave9

    Manual for a motherboard.

    The site merely has an expired security certificate and what is linked is a direct link to a PDF file. "Not secure" doesn't really mean anything in this context, you're not doing your banking there. :D Browsers can sometimes be too vague at explaining the situation. It's no less safe than...
  7. dave9

    Manual for a motherboard.

    Nonsense, override your excessive security. It's a valid link.
  8. dave9

    Manual for a motherboard.

    IPMSB Probably made for HP/Compaq, so being an OEM board, may not have proper/full manual (or I could be wrong, I stopped looking when I found what you sought), but this PDF appears to have the pinouts for the front panel and others...
  9. dave9

    connecting two batteries using 2 regs and one panel

    A diagram would have been better to show your setup. IF I'm following along, I'd get 30A schottky diodes, and put them on modest heatsinks. You did not list your location so up to you to find a supplier and what voltage they offer, obviously it should be a fair margin above your peak produced...
  10. dave9

    6v LED brighter with 3v battery

    ^ I like headlamps with the battery pack in the back (of the strap on your head), more balanced and don't stick out as far. For shorter term use where high brightness isn't needed, I have an ~ 80 lumen, Olight I3S, 1 x AAA (NiMH rechargeable) with the pocket clip on it reversed so it clips...
  11. dave9

    Amp repair

    It might help if you described the symptoms of what it isn't doing. Rather than test individual parts, one way to do it is think about how it works. You have power going in which you can trace with a multimeter, and signal coming from an internal source which you can trace to the output...
  12. dave9

    Charging different types of batteries ?

    ^ No, No, and No. The moment you wrote "actually" it was clear you were deluded. Don't use that word unless you want people to scrutinize what you wrote because all by itself that is a sign of delusion. The cells are 2.1V over the nominal lifespan. What some peak is when brand new is...
  13. dave9

    battery switch over help?

    It's a bit large, if putting it on the goggle housing, but would work otherwise. However I can't see the banggood pics very well but from your pic it looks like you'd be wiring it wrong. Each battery would go to the two end contacts on the switch and the center contact would go to the...
  14. dave9

    'Human body only" sensor

    There are cameras with built in firmware and software that can do human detection, but this is still cutting edge stuff and (consumer grade products especially, for the time being) are bound to have both false detections and failure to trigger human detection at odd angles and larger distances...
  15. dave9

    Charging different types of batteries ?

    Now about your other battery... escapades :eek: The screwdriver was built to a low price point with little care for battery preservation. It was not all that uncommon years ago before Li-Ion batteries, with their more demanding safety requirements, caused manufacturers to make more elaborate...
  16. dave9

    Charging different types of batteries ?

    The first charger is regulated to output 12.0V. A lead acid battery is called "12V" for convenience sake but is really a 12.6V battery comprised of 6 x 2.1V cells in series. In order to put charge in a battery you must input more than it's (present charge state) voltage, so to fully charge a...
  17. dave9

    Reducing voltage for a driver driven LED strip

    The buzzing sound is probably a resonant frequency of the inductor windings in the driver. I can't predict whether a little more or less current will help but it could. You'd change the resistance not the wattage. Another thing you can try if the driver isn't potted is open it up and lather...
  18. dave9

    'Human body only" sensor

    Heh, another one of those "I'm about to climb a mountain blindfolded, which way is the mountain?", topics. A suitably trained dog could do that, then you acoustically couple this sensor up to a bark-detector circuit. :D
  19. dave9

    Lighthouse project, flasher relay

    1) Those old solar lights probably use solar panels with a short lifespan, are not something I would design a new project around. If you want that type of panel I would at least buy new ones. 2) Those lights use a boost circuit to get that 1.5V up to the forward voltage of the (presumably)...
  20. dave9

    High current dc dc boost module circuits

    Go to ebay or Aliexpress, or whichever sites apply to your region and search for this.
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