FW3A, a TLF/BLF EDC flashlight - SST-20 available, coupon codes public

I didn’t have the graph earlier, but here’s how the latest thermal test looked.

This started adjusting from the highest current-regulated level, which measured about 1100 lumens or close to 3 Amps. Output stabilized at about 7 minutes. I haven’t tested it on full FET yet, but I suspect it will probably need some changes in the response curves to make it react faster.

Wow TK,the UI looks amazing. Thanks for the table and graph. Great work. Looking forward to playing with the light and using it as my EDC.

Pepinfaxera, can you put me down for a second light please.
Thank you

Do you know at what temp about it stabilized at?

For testing purposes, I set the limit intentionally pretty low. I was aiming for a stable level of about 200-400 lumens, and … that’s what I got. I think I told it that the ambient temperature was 20 C, and set the limit to 43 C, but I don’t remember exactly.

I wanted it to exceed the limit pretty easily and then step down somewhere slightly above the 1x7135 level. I could have set the limit much higher, but that makes the regulation problem easier to solve… and I wanted to see how it behaved on a harder setting.

Next I need to do full FET testing, since it’s the next step up in difficulty.

Looks like it worked as intended. Be interesting to see what it would do around 55c limit. What can the components tolerate? Typically up around 100c right?

I expect that turbo will overshoot the temperature limit before the light can settle to a stable level, so I wouldn’t put the limit too close to the hardware’s maximum tolerance.

The thermal sensor is inside the tiny85, which doesn’t have a great thermal path to the emitters. The measurements lag behind by quite a bit, so the response is lagged too. It tries to compensate for this by guessing where the temperature will be in the future, but that doesn’t entirely eliminate the problem. So the actual temperature goes higher than the limit at first, if the power is turned up high enough.

The firmware won’t allow a limit higher than 70 C… but it lets the user calibrate the sensor, so it’s not very hard to bypass that limit.

On a related note, that could potentially save a bunch of button presses while configuring things. If you tell it room temperature is 1 click (1 C), and then set the limit to only 1 click (30 C + 1), it’ll effectively have the same results as if you set room temperature to 20 C and the limit to 50 C. But the tempcheck mode will display numbers about 20 C too low.

I do not see him registered

In for one

Your name is already there nº 332 from The Miller list

A second unit?

Your name is already there nº 332 and 999

Updated list : … Post moved to Page 130 , FW3A, a TLF/BLF EDC flashlight - SST-20 available, coupon codes public - #3870 by pepinfaxera

Short list, Last requests .

I do not see him registered

Add me to the list please

I’d like it to blink on C

I vote for all A, B, C, and D.

I find the blinks very useful and not obtrusive at all.

There seems to be a lot of differing opinions about the blinks. Would it be feasible to have toggles for the various blinks in settings?

Thanks for all your attention to detail. This UI is looking amazing.

I think that the C blink should be before the end of regulation so we have time to stop while still in regulation.

Could you register my interest for 2 units please?

I’ve made my mind, I’m in for one unit

Hmm. Do you think votes should be limited only to people who are on the interest list?

Blink option running vote tally…

As a reminder, the options are: (where in the ramp to blink)

  • A. Floor
  • B. ~150 lm, level 65/150
  • C. ~1000 lm, level 130/150 (highest regulated level)
  • D. Ceiling


  • A: –7
  • B: 3
  • C: 14
  • D: 3

19 votes:

I’ve been saving each vote as sort of a trinary variant of Approval voting… capital letter for +1 point, lower-case letter for +0, letter omitted entirely for –1. Originally I had planned on doing regular Approval voting, but Pulsar expressed a lukewarm opinion about option C so I added a state between “approve” and “disapprove”.