Recent content by dave9

  1. dave9

    PCB MKL90W-02-C1 / 0500-0515-2180

    Thanks for the feedback. You might be surprised how much capacitors cost. I have them fail in all sorts of gear so just started stocking up on many different sizes of these very low ESR capacitors (I do hope that you used a major brand, very low ESR cap or it may fail again sooner rather than...
  2. dave9

    Do I need a constant current or voltage power supply to drive 12V Halogen lights?

    Yes that should work, but ideally for long life, I would want something rated for more than 5A, to power a ~3.3A load. Opinions may differ but when choosing a generic chinese PSU, I want more current margin than that, as some aren't even accurately rated in the first place. You could use...
  3. dave9

    2hp motor hums and not turning

    Is that a start/run capacitor hiding under that bulge I see on the side? If so then I'd check whether it's going bad.
  4. dave9

    How long does it take to charge a 500mAh battery with 5V 80mA?

    ^ Except you forgot the losses boosting the 3.7V battery to 5V for USB input to the phone, then the losses charging the phone battery.
  5. dave9

    Dyson V8 bypass sensors and alternative power supply

    Dyson V8's run at nominal 21V (6 cell battery) and 2800mAh, 40 min on standard mode w/o brush tool, but roughly 11 min on turbo mode. Certainly there are losses but before them that's 320W... and it's still too weak. I'd think about getting a 40V or higher, brushless leaf blower for the...
  6. dave9

    Fire alarm using a PTC as a sensor.

    There's nothing ideal about being knocked unconscious from lack of oxygen from the smoke, long before it got hot enough to set off a heat detector. Having the extra time to evacuate can be crucial. I'm sure there are some special circumstances where the opposite is true but try it for...
  7. dave9

    Fire alarm using a PTC as a sensor.

    High temperature sensing is terrible indicator of a fire, unless it's just the wax slug in a sprinkler head, activating it to save property. Smoke preceeding the temp rise will suffocate inhabitants, and the smoke is (usually) detectable using existing tech, far in advance of the temperature...
  8. dave9

    How long does it take to charge a 500mAh battery with 5V 80mA?

    There is no simple equation, because (presuming your 3.7V is Li-Ion) you're starting with a solar cell rated for max output, which you will not achieve in sequential hours over the amount of time it would take, then needing a charge controller to not damage the Li-Ion 500mAh battery through...
  9. dave9

    power supply Pace Sky Digibox 2600

    Something is not working with the image attachment view counter. I click/viewed all three images but the counter still shows "Views: 0"... after refreshing the page too.
  10. dave9

    power supply Pace Sky Digibox 2600

    What is the evidence of no longer receiving power? You'd pick a spot and trace backwards along the power path, identify faulty component, identify the type of component (suitable replacement candidates) and swap it in. Parts may be available at electronics suppliers, which ones depending on...
  11. dave9

    USB Charger and Buck converter

    You are working with a quite low, 1.7V max vDrop from your regulation circuit. I would try to find a PWM buck, current regulating driver instead of what looks like you are just setting a voltage regulated driver to "about" what the LED would need for a target current. I used to get such things...
  12. dave9

    Can this ceiling fan remote be fixed?

    ^ I think it's more likely something like a pairing code that the DIP switches set, and no the dip switches can't change the saw threshold which is just shunting to ground, but I wouldn't put too much work into this when (if you're in the US or another market with amazon or ebay available) they...
  13. dave9

    Can this ceiling fan remote be fixed?

    ^ It reads: H P303A (or maybe R303A) See this page, states 303.9MHz and you can see how this is situated in the casing: https://www.amazon.com/Ceiling-Replacement-L3HFAN35T1-FAN-35T1-L3HFAN35T/dp/B0922K9NJD The FCC pic has one that's 303.875...
  14. dave9

    Can this ceiling fan remote be fixed?

    ^ BINGO! This is an RF remote, not IR. Besides, an IR LED can't cycle anywhere near as high as ~300MHz where these operate and was stated plus the orientation of the LED, that it's just a visual indicator that a button was pressed. Stupid question but, did you check the battery voltage? Is...
  15. dave9

    Issues with replacing Dead Laptop Motherboard...

    I'd assume the new board is DOA and seek a refund.
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