【Sofirn H35B headlamp upgrade】

Hello friends in BLF, this is Sofirn.
Does anyone have the H35B headlamp? How do you like it?
Recently we’ve been thinking about upgrading H35B which uses 3* SST20 LEDs+ 2 XPE Red lights

Here is our plan: :nerd_face:

  1. 2SST20 LEDS (6500K) + 2SST20 LEDS (4000K 95CRI) + 1*SST20 DR (red 660nm)
  2. one mode for 4000k leds, one mode for 6500k leds

But now we have following questions: :thinking:

  1. Do we need one mode for both of 4000k and 6500k LEDs?
  2. How to arrange these 5 LEDs? Is this ok?

image

With these various LEDs and channels, it will be difficult to design the UI.

What do you think? Are you interested in it? Feel free to leave a comment! :smiling_face_with_three_hearts:

3 Thanks

The LED arrangement is fine, but the LED choice could’ve been better. The LH351D 5000K would’ve been a better alternative for the high CRI channel. 519a would’ve been perfect but cost would go up significantly, and the LH351D is easier to drive than the 519a. The SST20 6500K is fine for the long range channel, but the SFT25R is right around the corner, and there’s these mistery chinese round die LEDs that are showing good performance. The CCT difference between the SST20 and LH351D would be smaller, and with a button press combo we could swap between the flood high CRI channel and the long range channel, with another combo for switching between white and red.

No need for a mode where both channels are active, it only makes for a more complicated UI and possibly more heat.

2 Thanks

Hello Sofirn.
I do have one of these, it performs quite good, however I personally don’t prefer cutout-reflectors for their messy beam profile and high losses in spill-light.
Of course with 5 emitters in a light like this, it’s understandable though, but it would still be great, if you could replace it with a custom TIR-lens.

To your questions /
1: I would appreciate a mode for both channels anytime, first the tint-mix should look awesome, but also more emitters means higher efficacy and thereby less heat and longer runtimes, which this light certainly needs.
And if the UI is made similar to that from the “Wurkkos HD50” for example with a “click-hold”-command to cycle the channel-modes, it shouldn’t be too complicated either.

2: The red emitter in the middle is perfect, but I think alternating the white emitters to one-up one-down for both channels would give a more balanced beam profile in case you keep the reflector, also the heat is spread a bit more evenly.

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I like the idea of a floody hi-CRI-channel and a throwy coolwhite channel. But that’s already the case in all the other multichannel-headlamps from Sofirn and Wurkkos, so to keep this a tint-mixing light would be alright.
Please don’t use “SST20”-LEDs though, the efficiency is pretty low on the 95CRI-versions. To my knowledge the “Latticepower TN3535” is also available in a 90CRI-version too that is even more efficient than the “LH351D”, but either one would be better, if cost-savings are priority. The perfect one would possibly be the “Cree XP-G4”, if you can get it in the “HI”-version without dome. It’s very efficient and throws far. Also it would be amazing for many enthusiasts if these emitters would finally be commonly available.

One more wish, many of these newer headlights have glued or maybe pressfitted bezels. Please keep the current one, just … screw it all !. It really makes for a good base for modifications. I have several “D25S” and “D25LR” with changed emitters and optics, and they are very useful. Having a more powerful alternative would be very welcome.

Anyway, thank you.

I had one of these but couldn’t stand using it. It kept on stepping down randomly even on a full charge. Also tried different batteries but it had the same behavior. Hope this is addressed with the upgrade.

1 Thank

Agreed, the use of a timed stepdown really seems inapropriate for a light like this, it should if so, only be done in large handheld flashlights with tons of thermal mass and relatively little power.
But here it either reduces power prematurely or when driven at high or turbo, it doesn’t prevent overheating as the user keeps reactivating due to completely not feeling the heat build up through the headband. This could be quite dangerous with the heat sources directly on the side of the battery and it itself strapped onto someone’s face.

Regardless of it is a timed step down or not. I kept on experiencing it within the first 30 seconds of turning it on. It felt like it was a dud or faulty code. I guess We can’t really expect too much at this price range. Never experienced this with the old D10 drivers though so who knows. Not knowledgeable enough for a proper conclusion.

Strange, could have been a one time-defect or do you know this behaviour from other lights ?.

A light I got from SZFEIC has the same irritating behavior. No other lights from Sofirn though IIRC.

5 LED is not upgrade. 7 LED is upgrade, or 9 LED even better.

1 Thank

11 would be optimal of course, like this abomination.

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On larger handheld flashlights I would indeed highly appreciate it, having more emitters for a better beam and higher efficacy. There was the “Mateminco MT07” and other Models from Noctigon and Fireflies, but today there’s barely any affordable equivalent.
I wish Sofirn would make a large Floodlight for single 26–36mm cells again, with 7–12 nice emitters under individual high quality TIR’s, and of course powered by a buck- or boost- +FET-driver with Andùril.

2 Thanks

@ Sofirn - Don’t try to pack a thousand functions into the lamp like the HS21. Take the H05A as a basis, add 5 High CRI LEDs 5000K and a constant power driver and three brightness levels. The perfect flood work lamp is ready.

1 Thank

Old comment I know, but that wasn’t a fault, that’s just the firmware on these cheap headlamps. There’s no thermal regulation, so a 30 second timed stepdown on turbo exists.