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  1. dave9

    PSU 5V line seemingly not performing

    Use the bottom of the PCB to trace the circuit away from the caps towards the input. Test everything in that path, and compare voltage readings to the other PSU, both when under load, connected to the system.
  2. dave9

    PSU 5V line seemingly not performing

    I would test the diode just before the 5V caps.
  3. dave9

    PSU 5V line seemingly not performing

    I don't understand your issue. Put the caps back in. Measure the 5V rail in question. Is it reading near 5.0V while connected and powering the system? Filter caps for this type of SMPS tend to be fine until they vent, particularly when not near peak load. There are exceptions but it seems...
  4. dave9

    Old module does not work

    Plug the module back in, have a helper active the headlights while you measure for a voltage drop before and after the relay contacts. If the drop is insigificant, move on to the lamp assembly. If power doesn't make it that far, move backwards on the module, then the wiring diagram towards the...
  5. dave9

    Where could I salvage an LM317 Voltage regulator?

    Thanks Harald... Then I better delete mine so it doesn't look like I'm talking to hevans.
  6. dave9

    Old module does not work

    It is usually better to *first* ask (or search for as I did to find the link below) automotive circuit questions in a forum for the respective model and generation of vehicle, where fellow owners have probably already encountered the fault once a vehicle gets older, and may have wiring diagrams...
  7. dave9

    replace a 9v power outage backup sorce

    Yeah this is the worst possible forum to have a file size or resolution limit. Far better to embed a thumbnail pic for those who don't have the bandwidth, that links to the order of magnitude larger image. If it's not a 6MP or larger image, it's an insult that wastes our time. Even a phone...
  8. dave9

    Home made battery packs

    I'm glad you're working with small alkaline batteries instead of Li-Ion, let alone AC mains power. :oops::eek:o_O
  9. dave9

    replace a 9v power outage backup sorce

    Not necessarily, I've owned several LED clocks that use one for backup, as well as a weather alert radio.
  10. dave9

    replace a 9v power outage backup sorce

    I wouldn't even bother with a charging circuit. Instead, get two 9V NiMH batteries, determine how long they last, then swap one with the other charged battery within that interval... charged externally, assuming the memory is retained as long as the unit has mains power, not completely...
  11. dave9

    PC pay Capacitor I believe to be bad. Looking for a replacement but need guidance.

    That is already a fairly tall height to diameter ratio capacitor, so the 16V cap is probably larger diameter, and may also have a wider lead spacing, 3.5mm vs 5.0mm. Since it is an older (aged) PSU, if it is not larger diameter, it's probably not a high quality capacitor. One trademark of poor...
  12. dave9

    Energy storage - alternatives to batteries

    You seem overly vague and all over the place with illogical concepts. Where do I even start? - You are trying to make a toy that nobody will use for long because it is underpowered and excessively expensive, so there is the manufacturing impact and the landfill impact. It is not appropriate...
  13. dave9

    Energy storage - alternatives to batteries

    Have you ever seen the cartoon, the Flintstones? Seems like a bad design to build a remote control car that needs electricity anyway and not use the same battery pack for propulsion when it needs to be so tiny/slow that it can run 10 minutes on 10W or less. Why are you reinventing the wheel...
  14. dave9

    Can I use a higher amperage power supply for a fan that requires much less current?

    Yes, it's the voltage that matters. Current just needs to be equal or greater than the load, with some margin for long life.
  15. dave9

    What type li-ion battery use in cordless power tool protected or unprotected

    Manufacturers of tools with user-replaceable individual cells, could go either way, placing the burden on the owner to use a protected cell, or building in a protection circuit into the tool. Tools that don't have user-replaceable individual cells, instead integrated into a battery housing...
  16. dave9

    LED slim tube LED driver replacement

    No need, replace the faulty discrete component. If you must for some reason, make your own, then you must first determine how the LEDs are arranged in a series and/or parallel arrangement, the target wattage, and then the voltage and current regulation to get there. Is it really worth the...
  17. dave9

    Wifi router does not turn on after outage (not what you think please read)

    This is practically impossible. I call shens.
  18. dave9

    Need a new multimeter - any thoughts

    This is too broad a topic for a single forum thread. Define your budget, look up what models fit within it, and check out some youtube shootout style videos that compare meters within that price point. Generally your choices are do you pay for more durability and/or safety, or more features...
  19. dave9

    Supercapacitors anyone?

    Someone has surely mentioned it already, but why don't you just tap into a circuit that is not switched off while the vehicle is cranking, or wire directly to the battery with a fuse added there if you're willing to suffer constant parasitic drain by leaving the 5V adapter plugged in, rather...
  20. dave9

    How long lifepo4 battery power tv

    We need to know exactly what this "battery" is. It cannot be just a battery and be 12V, the sum of a series of LiFePO4 will not equal 12V nominal. Further, how was the TV average wattage determined? We are left assuming things that I am not comfortable assuming, if you needed assistance...
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