Challenging Project

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Last seen: 9 months 2 weeks ago
Joined: 12/01/2019 - 05:25
Posts: 3
Location: Italy
Challenging Project

Hi, this is the first time I write here. I’m not a real flashlight nerd but I do love led and light

In past years I lurked around the forum taking advantage from the knowledge on leds and optics.
Thanks to that knowledge, I managed to retrofit an old operating stereo microscope with a cree xp-l hi led after the original alogen quarz bulb passed away.
After several years using it im pretty happy with the result.

Now in my mind is taking form another project, but I need again your knowledge.

I need a surgical compact headlight that must undergo some critical features:

Group A features are MUST:

  • uniform spotlight 5-8cm diameter@ 30cm working distance
  • compact diameter max 30-35mm or lower(better)
  • lightweight (under 50g)
  • minimum 50000 lux. @30cm
  • hours of semi-continuous usage(efficiency and/or heat management)

Group B features are DESIDERABLE but not mandatory

  • stepless dimming (rotating nob)
  • 5V powerbank operated(those which run on multiple 18650s are perfect i think)
  • no spill (or at least not a strong one)
  • Elcheapo style (there are surgical light on the market that meet or exceed some of my requests but go from a bit under 1000 to 5000€) I know we can do better!

My actual options are:

1* buy a thrower, cut off the head and add cable and battery pack (ledlenser p5?, lumintop gt nano?, others?)

2* build it from scratch, buy an LED an optic and a driver and try to put them in a case (XP-G2 dedomed? aspheric lens?, TIR?, reflector?)

for these option I really need your help because i dont know the best combination/option out there
I love diy projects though I am not very confident in electronics

3* buy one of those surgical branded light and admit defeat Crying

thank you very much in advance for your contribution Wink

Last seen: 3 months 2 weeks ago
Joined: 11/01/2020 - 05:42
Posts: 76

Sofirn HS05

Lumintop FWAA + headband

both are <50g and can be crazy bright on 14500.
though with the HS05 you’ll find an Eneloop puts out enough juce to make it become warm quite quickly, more power = more temp.
for least weight you’d go with HS05 + 1.5V lithium non-rechargeable.

you can make the beam more floody by putting DC-fix on the inside of the front glass
both should be perfectly washable with soap.
the headbands you can throw into the washing machine.

Last seen: 9 months 2 weeks ago
Joined: 12/01/2019 - 05:25
Posts: 3
Location: Italy

thank you for the input….i looked out for those two but I think them are a bit floody for my purpose and with all that power I’m afraid I cant use them for very long time (i.e. 2h of continuous output)

YuvalS's picture
Last seen: 2 days 17 hours ago
Joined: 09/26/2018 - 10:39
Posts: 558

I took a look on these commercial lights and it is ridiculously expensive with no reason.
Since you don't need waterproof at all (unless blood splashes are an issue) I don't see any problem building it yourself for a lot less money.
The only problem I have no Idea what emitter+lens combination will give you 50000 lux. @30cm but I am sure many knowledgeable guys here can answer that 
I recommend using a GoPro connector since you can buy many head harness with this connection. 

I have no idea abut surgical light but i believe color temperature and CRI are important, you may want to figure out what emitter is used in the commercial lights and use the same one.
Also I think it is more suitable to use constant current driver for this application (not PWM).

After you find the optics and emitter I am happy to help you with the physical design 

My FW repository

My BLF/OL contest entries: 7th 8th 9th 

Last seen: 9 months 2 weeks ago
Joined: 12/01/2019 - 05:25
Posts: 3
Location: Italy

Thank you.
Since my project resemble a quasi-pure thrower I was thinking about xp-g2 because has lumen has efficiency and a relatively small LES, maybe a XP-P would do better. I was thinking also that TIR could focus more light with less spill but I’m not very knowledged on them.
Let whait the experts come in.