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  1. dave9

    LM338 Voltage and Power Questions

    ^ Yes of course, a typical CPU heatsink could easily handle that with a fan, but it's quite lossy. What I would do is (use switchmode PSU as already suggested but keeping closer to your agenda...) try the circuit using the transformer center tap for 12V. Remember that is AC, so once rectified...
  2. dave9

    Trying to match an old terminal block

    I'd guess nothing that big is made any more, but you could include a picture in case anyone has some of those or knows more.
  3. dave9

    My air purifier fans won't turn anymore, making humming noise

    ^ I've never had that happen to any I've lubed w/o cleaning. I kinda, woulda, noticed that. The issue is not just bearing type, rather that these cheap little shaded pole motors have such a small shaft diameter and bushings, with small oil reservoirs too. Further in an effort to be even...
  4. dave9

    My air purifier fans won't turn anymore, making humming noise

    I've not noticed much difference between just oiling them and further disassembly to clean before lubing. The main difference was that they get oiled before the bushings get that far chewed up so they don't have so much play in them that the shaft wobbles and pumps the lube out faster than...
  5. dave9

    LM386 Alternative (Simple but slightly more power?)

    ^ Sure, I was assuming tiny meant smaller than a pair of 3" drivers + enclosure, like less than 400 cm^3 Sometimes finding (or making) a nice enclosure is the larger part of a project like this.
  6. dave9

    LM386 Alternative (Simple but slightly more power?)

    ^ I'm confused. Are you suggesting an attempt at "hi-fi" with slapped-together <9V setup? It's a recipe for low fi, a project to "get sound" out of it. Frankly, I don't see any point in the project at all. Tech changes, as must DIY efforts if it is to be a useful end result rather than a...
  7. dave9

    LM386 Alternative (Simple but slightly more power?)

    Given the purpose, I'd do some trolling on ebay to see what they have that's a ready made class D product. I used the word "stereo" in this search below just because it returns more hits for the bare modules, but there are some mono versions or just don't use the 2nd channel...
  8. dave9

    Coronavirus transmission prevention device.

    Giving it a few seconds of serious consideration, my hands come nearer my head quite often, but hands near my face (inaccurate proximity such as you described as "eg an amulet or neck band" ) doesn't necessarily mean I'm touching my face, let alone sticking my fingers in my mouth, nose, or eyes...
  9. dave9

    SM12 ?

    and the notes, and pictures, and ... Is this something you're building or repairing and either way, on a custom PCB where you need a certain form factor IC, or just the function of regulating from one voltage to another (12VDC?) ?
  10. dave9

    LED Light Bar Power Source and Wiring Harness

    The picture of the switch shows that pin 3 on it goes to the light. The thing you do differently is take that to the relay coil like shown on the diagram Kiwi posted. Coil pin 86 also refers to the diagram Kiwi posted, the relay pin #s on that are a very popular arrangement. If your relays...
  11. dave9

    Reducing battery charger output

    I'd measure resultant current when that is put in place with the battery fully charged already. If it's more than a couple dozen mA it is too high. Even that, maybe too high for long term storage. Even an AGM battery can have outgassing if the electrolyte is being liberated. As Bluejets...
  12. dave9

    LED Light Bar Power Source and Wiring Harness

    You'd wire it exactly as shown except pin 3 "To Light" going to both relays' coil pin 86 to have one switch operate both, and then switch pin #7 & #8 "To Ground" going to any ground, either chassis metal near the switch or wherever you joined the other grounds together like shown on Kiwi's...
  13. dave9

    LED Light Bar Power Source and Wiring Harness

    The switch "should" only be handling the relay coil current, which from looking up the part #, appears to be a bit under 200mA @ 14V, so doesn't need to be of much current handling at all, just durable enough to survive an automotive environment. Similar might be true of the wiring harness, to...
  14. dave9

    Strong slide switch

    If the switch slides too easily, all you need is a rail with mechanical detents. This is pretty easy to do, two parallel metal (or plastic if you like flimsy) plates sliding, notches in one plate, and a ball bearing with a channel behind it that has a spring to provide tension for the ball bearing.
  15. dave9

    LED Light Bar Power Source and Wiring Harness

    These types of lights with the 9V to 30V range have a buck current regulating circuit inside, so there should be no issue hooking it up to your jump starter, except that jump starters are typically not very high Ah capacity so you will have a limited amount of time to run them from it for...
  16. dave9

    Next Smoke Detector Millionaire or Not?

    Your post makes no sense. If you have to replace the battery once a year, you are the very last person who would be a candidate for a rechargeable battery.
  17. dave9

    Questions cable controls snes

    There is no forever. Follow best practices or don't but the worst thing to do is waste time while time still has its way...
  18. dave9

    Questions cable controls snes

    I know nothing about Brazilian Auto Parts stores, but any with a good stock of products should have an entire wall devoted to cleaning and conditioning products. Amazon.com.br appears to have Mother's Vinyl & Rubber Care, perhaps other suitable products too. Normally a conditioner would have...
  19. dave9

    Questions cable controls snes

    lol, I'd try the vinyl conditioner first because once you put that on, nothing else is getting into the pores. That is more of a protectant than a conditioner.
  20. dave9

    Questions cable controls snes

    You could try an automotive vinyl/rubber conditioner product, but if it's vinyl and had significant UV (sun) exposure, it may eventually crack apart no matter what you do except to avoid flexing it much.
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