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  1. dave9

    Advice about MC34063 based buck converter diagram

    It could be on the same PCB as a daughter card, just put pins on your board to form a riser, solder to the I/O on the regulator board. That would work better with the one Bluejets linked than the one I linked because it would have pins on all four corners to support it.
  2. dave9

    LED TV BACKLIGHT

    1) Give it a signal then shine a strong flashlight at the screen to see if it is functional and all that is missing is backlight operation. There are probably youtube videos for TVs and/or computer monitors demonstrating this. 2) I would simply trace the circuit and observe where power (and...
  3. dave9

    question: car amplifier at home (diy)

    I feel that I have contributed enough that this is complete. How much amperage to pay for is up to you. We, another member and I have already stated that you shouldn't need hundreds of watts.
  4. dave9

    question: car amplifier at home (diy)

    Yes, it is not necessary to crank it all the way up. If you are able you might also reverse engineer the amp and change the gain on it. Ideally a full turn of the volume knob will be a full range of available output power. Granted you can artificially get that with a different resistor value...
  5. dave9

    question: car amplifier at home (diy)

    Sure but consider that he has used these in a vehicle so probably already has severe hearing loss and needs the volume. ;) Personally, I too, think shooting for lower wattage would be reasonable. I'd hook it up to an ATX12V computer PSU since I have some lying around. I also have old...
  6. dave9

    DIY bluetooth speaker

    I would own an 18V cordless tool collection and use a battery pack from that, and charge it with the intended charger. I'd buy the cheapest tool I could find with that battery interface to cannibalize it for the mechanical connection, a dead for parts tool off ebay or something from a pawn...
  7. dave9

    Difficulty measuring forward voltage for a LED

    Quick and dirty way I would do it is if it's a white LED, figure about 3.2V/die, and since 12V LED, "probably" 3 dies in series (even if there are parallel series for a multiple of 3 dies in total), then calculate for 3W or whatever your power source and/or heatsink will support. That might be...
  8. dave9

    Advice about MC34063 based buck converter diagram

    I just remembered that years ago I tore apart a Belkin F8V718 vehicle lighter outlet to phone charger adapter that used an MC34063, and had made pics of the PCB for it:
  9. dave9

    Advice about MC34063 based buck converter diagram

    I would just buy a $1 buck converter board off ebay, or aliexpress, or wherever you prefer. It will cost a small fraction of what the individual parts would cost to build your own, and save hours of time for your first try. Here is one example, there are a dozen of them that would be suitable...
  10. dave9

    Capacitor as backup to 12v train camera system power

    I would sooner use a 12V battery, so not only the step down board receives continuous power but so does the train (motor) itself, while a supercap array would be too massive and expensive to reasonably power both. Whether to use lead acid, Li-Ion, or NiMH, is a different topic onto itself based...
  11. dave9

    6v LED brighter with 3v battery

    Because when the circuit is trying to pull more current than the battery internal resistance allows, you get voltage droop. The real question is what the LED specs allow for max current, which may also depend on how well it is heatsunk (or in this case, heatsinking an encapsulated bi-lead LED...
  12. dave9

    How to power one or two of these clusters

    Although the LED page you linked has 3 different LEDs on it, all seem to have a series of LED dies internally at 300mA current, and the linked driver page also has multiple models, but all at 300mA current, so yes it appears the driver should be suitable if you pick the one with a corresponding...
  13. dave9

    Install gps tracker into working 18v lithium ion battery

    Bluetooth is far too short a range to be much good for tracking purposes... usually thieves don't stick around but if they did on a jobsite because they have to be there working, they'd probably hide their ill gotten goods in a metal vehicle which substantially reduces the effective range even...
  14. dave9

    PSU Clicking

    To back up a bit, are you sure it is the PSU clicking and not a protection circuit on the amp board? What I would do is look over the PSU board to see if it has resistors on the output to give it a minimal load. If it does, I'd try powering it without being connected to the amp board to see if...
  15. dave9

    Running cool box on my car battery

    If it is peltier based it will operate continuously at full load and struggle to do much cooling at all at only 4A, but even that might be some conservative rating. Personally knowing how little the peltier type cools, I wouldn't leave it on for a moment when the engine is off. Do, do your...
  16. dave9

    Power supply from china

    The two greatest areas of concern on this type of Chinese Junk :p are usually the switching circuit output capacitors and the fan. Lube the fan regularly or replace with a high quality dual ball bearing model at least 20mm thick. Replace the output capacitors now with quality very low ESR...
  17. dave9

    PCB Design, 12V@N*0.6A, traces, how can i make this work

    You do know that they make computer fan controllers? They're about $15 delivered for a basic no-frills bay mount style, but the PCB could be removed from the bay mount if it needs to be. Why did you write "thin trace" (on a PCB)? Merely use all available space for this trace, don't try to...
  18. dave9

    Increasing Battery life Question

    Check the current rating of the lighter output on your portable power pack, it may not be suitable, and/or if your lighter adapter plug is not high quality, it may not be suitable for the current needed. Yes you could use a portable 12V source but you'll want a switching DC/DC buck converter to...
  19. dave9

    heating element

    In my experience one of the greatest weaknesses of those Hakko clone soldering stations (outside of what a perfectionist wants, I mean to just use it to solder) is they use low quality wand wire that is prone to internal breaks. For this reason I would buy the entire wand, to get new wire as...
  20. dave9

    Door Bell Chime Transformers - UK

    With wiring already in place, I wouldn't want the extra recurring burden and expense of replacing batteries, and depending on location, distance and metal obstructions, and RF noise in the area, some wireless doorbells may have spotty results. If it is the type that is encased in a metal shell...
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