Recent content by DIWdiver

  1. DIWdiver

    100ish watt xhp 70.2 watercooled build.

    When most people talk about a mosfet driver, they talk about a device where the fet is intended to operate like a switch, and the current is limited by a number of things, including the battery, LED, wiring, and yes, the fet. For this to work, the LED and the battery generally have to be pretty...
  2. DIWdiver

    Hole in beam 5 mm LED

    Larger LEDs typically don't have bond wires crossing over the top of the die. But I've never seen a 5mm LED that didn't have a bond wire right in the middle of the top of the die. It's not hard to see if you have good eyes or good magnification. In a fairly narrow beam LED, the bond point and...
  3. DIWdiver

    XPL vs XPL-HI

    The XP-L has a dome on it, the HI doesn't. The dome increases total light output in lumens (explanation on request), but it also magnifies the apparent size of the die. This causes a reduction in the apparent surface brightness of the die. Surface brightness, not total lumen output...
  4. DIWdiver

    RC car batteries - LiPo v Li ion, chargers

    AFAIK, cylindrical cells are either LiIon or LiFe, while soft-sided pouch cells are LiPo. If you have something else, then all bets are off. As vicv says, LiIon and LiPo are theoretically interchangeable. However, the issue is often that one doesn't physically fit very well in an application...
  5. DIWdiver

    PN2222A LED Circuit

    The '2222 is perfectly satisfactory for this application. A '3904, well, maybe if you're not picky. With 5V supply and Vf of only 1.35V, the Vcesat of an appropriate BJT (including the '2222) is almost insignificant. Whether it's 0.1V or 0.2V hardly affects the LED current. Make an educated...
  6. DIWdiver

    How to remove star

    If the existing compound is rubbery, it should be pretty easy to pop off the star and scrape off the residue. If the existing compound is pretty hard, it's probably an epoxy, and may take quite a bit more to pop off the old star. Acetone will soften or dissolve some epoxies. It takes quite a...
  7. DIWdiver

    New lifepo4 batteries

    So... Most phone and tablet batteries are pouch cells, laptops are a mix (recently mostly pouch) and until recently most or all tool batteries were cylindrical. The only fires that I hear about are in phones and tablets. Do tool fires happen and I just don't hear about them? Or are tools for...
  8. DIWdiver

    Runtime at medium power with 18650 vs CR123

    Maybe true, but you can get 95% of the maximum capacity without running them totally to the ground. And if you recharge them fairly soon, you can avoid doing too much damage. If you run the batteries down frequently, the economics are hugely on the side of LiIon. If you don't run them down...
  9. DIWdiver

    Dive Light Build

    I have an Amp1L. The cone is removable. I'll see if I can dig it out and see what it does. I bought it as a backup, and haven't really used it. It has no modes, just on and off.
  10. DIWdiver

    Cell balancing

    I think the general practice is to have a balancing charger, and a protection circuit in the pack. Done well, an active balancing circuit is a bit bulky and expensive to put in every battery pack. Buy it once in your charger and you're done. Passive balancing isn't bad, but active can handle...
  11. DIWdiver

    Please help me build a frugal caving light - driver choice?

    Okay, a few things I notice. First, I'm glad you didn't say you wanted it for cave diving. For caving, an experimental light must have a backup. For cave diving, you must consider any experimental device as useless for safety. It sounds like you use the word 'frugal' to mean you don't want...
  12. DIWdiver

    How should i ire these led lights

    It looks like he has two drivers in his kit. I think we need a bit more information about the drivers to say for sure how to wire them. Just guessing, I'd say red wire to + on the LED, blue to -. Battery input goes + to the center pad on the driver, bat- goes to outer pad. Disconnect the...
  13. DIWdiver

    is a li-po 4s 14.8v, the CHEAPEST WAY to jump start a car (with dead battery) ??

    For 18650 cells, I haven't seen super high discharge rates. But for LiPo pouch cells, I've seen continuous discharge rates as high as 85C, with pulse rates as high as 170C. If you had just a 3A-H cell, that would be over 500A! These cells would be suitable for automobile starting even if the...
  14. DIWdiver

    Soup can light, high amps with CC, is it possible?

    Yes, it's not surprising to find the driver and LEDs on the same MCPCB. No idea why there are 4 wires on each switch. Does it react differently to slight and full depression? I would guess that the multiple wires to the battery board suggest the batteries are not all simply in parallel.
  15. DIWdiver

    Soup can light, high amps with CC, is it possible?

    I'd want to measure the input voltage at the LED board to see if it is really 3V. If it is, you could put any combination of LEDs that will fit on the pads. If it's higher than 3V you'll have to map out the board to find out if the LEDs are pairs. You'd need to populate both LEDs of a pair...

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