The There Are No Stupid Questions Thread

I agree. That happens far more than DUI of substances.

Yep. The extra middle men and the state all need to take a piece now. However, growing it is relatively easy, given how cannabis is like a weed. I’ll bet growing it without a license to do so is considered a crime, but in very small quantities (for yourself and friends, not for resale) I doubt police could be bothered.

My brother is enjoying and using the lights we got him for his B-day (M3-C, FC11) but he’s still looking for one that’s shaped like a Sofirn SF47 He doesn’t actually want an SF47 because he thinks the beam is too floody. And he doesn’t want a mult-switch design. (ruling out the SF47T)

Put plainly, he’s looking for:

  • 2 x 21700 in series (for form factor reasons)
  • smallish head/reflector (approx 2 inches)
  • somewhat focused beam (I think he hates flower petal beams too)
  • single button interface.

Im looking at picking up a D4SV2. Probably the dual channel version.
Its not going to be half as bright as the regular D4SV2 (using four of the same LED) is it?

Edit: Dual channel 5000k LH351D’s vs a single channel with 4 x 5000k LH351D’s

If I were to decide I dont like the 2nd channel very much, and end up primarily using it on the LH351D channel. Would I be gaining or losing anything compared to the single channel 4 x LH351D’s?

I think It would be nice to have the W1’s in the second channel, but also think its possible it wont be as useful as Id like.
Curious if I should just write that idea off now and go for a single channel with 4 x 5000k LH351D’s.

Is it safe to use my Alonefire X28 flashlight as a charger for my QB 26800s?

What would happen if a nonchargeable lithium or alkaline AA battery was charged in an AA charger? Would it blow up? Would it charge? I assure you I have no intention of doing it. AA’s are cheap. Just wondering.

My dad (an electronics technician and raido operator for nearly 50 years) used to recharge dead batteries that he brought home from work. I don’t remember if they were zinc-carbon or alkalines, but I know he had modified his chargers.

For the record, he was born in 1933, and grew up on a farm during the depression. So, he was what you might charitably call a cheapskate.

Also, wikipedia says about alkalines:

and Quora on recharging zinc-carbons

Without going into the details as this was sooo many years ago; Ray-0-Vac had these “Renewal” chargers for alkalines. Got one for AA and sure enough recharged some cells. And as stated in the above quote from manithree, didn’t fully bring back the capacity. Also, not all Alkalines would work. The older models of Duracell would, but they changed the chemistry (wouldn’t want to kill a very profitable disposable product line, would you?). These newer batteries wouldn’t do anything - no leakage nor any heat.
It was said the charge profile was a square form with periodic ‘rest’ periods. Either pulsed or other. Not well understood at the time.

Using a standard NiCad/NiMH charger I wouldn’t attempt. I’ve had so many leaky Alkalines that these “destroyers” are my main reason to convert about anything to Li-Ions.

Yeah, back in the day, there were “battery fresheners” that would indeed force back something of a charge to fading cells.

But cells had thicker walls back then, so even completely spent they’d rarely leak. C-Zn cells sometimes, alkalines rarely(!!).

Today’s “efficient” cells use so little material in the walls that it’s a race between developing a hole and thus a leak, or someone tossing moribund cells.

And alkaleaks are… alkaleaks.

And to add to those lines

Can’t fathom why manufacturers make modern-day meters with a 2.8 Volt threshold. Can’t use Laddas (NiMH).

Just found a small 13 x 48mm Li-Ion cell buried within a disposable Vape Mod – chucked alongside the sidewalk. Seems to be able to charge. Will be looking into adding a charging board and 3-volt regulator. It would fit in one of those meters, and then bypass the auto-off function (user selectable from the ‘ON’ button sequence).

I have some spare 219b and I am thinking about reflowing in a SP36 BLF.
Zeroair says the FET is about 13A so it should be fine right?

I see ”16.2+” in Zeroair review with sofirn cells (60mΩ) and LH351ds, 219bs having lower Vf will pull more current, and if quality cells (e.g GAs 30mΩ) are used then even more current, I’d say it will be too much for 219bs.

I will just be using Sofirn cells which shouldn’t last 16a for long. As long as 219b can survive that then it should be fine right?

No elbow room.

You would have to change the sense resistor, the light has glued driver – can’t take pics.

Ah, I see what happend. I was reading 1lumen’s review instead of zeroair. Zeroair has the Anduril 2 driver. On 1lumen’s review and it says

“Bottom of ramp (moonlight): 2.5mA
Top of ramp: 4.38A

Turbo:
Sofirn Cell: 10.9A
30Q – 11.9A

The light seems to cap out at the ~12A mark which may be a hardware limitation”

I took a plunge and tried it this morning. I reflowed sw4500k and it’s working. Visually, the SP36 on step 7 is about the same as a D4V2 SW4500k (9a, turbo, floody) from 20 feet away. I will have to wait for night time for wide area test. The first revision SP36 hardware limitation became a feature. Maybe that’s why it’s heating up faster than expected for its mass. Now I just need to find a way to diffuse the beam even more.

Yeah, sometimes it’s “go or bust”. Nichia’s 219b has a reputation for being low Vf. It may deter the life of the LED, but as you seem to grasp that the battery doesn’t always deliver those Amps, may just work out.

Still, if you draw 16 Amps at the tail, you’d be pushing those LEDs at the very max. May not burn out immediately, but will eventually fail.

Now that the dust has settled a little, just how good is the Nichia 519a emitter? Do they match the output of the LH351D emitters while having better R9 and tint?

Is it harmful to ceiling bounce UV light without safety glasses? Do I have to watch out for mirrors in the room? I will be using the Wurkkos WK30 365nm.

The prescription is to not have the light shine directly into the eye(s) or on the skin.
It’s not a laser. Any reflected UV or indirect exposure is relatively safe – not prolonged though.

Is Simon’s 12- and 13-group biscotti-like firmware open source?

If so, where is the source repo?

No. No idea who he uses to make and program all his drivers now but doubtful they’d give up their work freely. You could always message Simon and ask if sharing it is possible.