EEVblog #67 – Hacking the Princeton Tec EOS LED Headlamp with a Cree XPG

Author: admin  //  Category: Hacking


Dave does a teardown of the Princeton Tec EOS headlamp and mods it with a new Cree XPG LED. Throw in a quick reverse engineer of the circuit, gratuitous scope shots, torturing a thermistor, a practical demonstration of why you really do need 5 multimeters on your bench, and as usual Dave finds no problems filling up 25 minutes.

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13 Responses to “EEVblog #67 – Hacking the Princeton Tec EOS LED Headlamp with a Cree XPG”

  1. tecnolover2642 Says:

    Another question, with your mod using the XP-G LED and a 350-400mA current what is the LUMEN output on HIGH now??? Also, do the cree led’s come with a star mount?? do I need to buy a star mount or can I use the stock one already in there and just remove the old LED and put the new LED on?? also,, is heat going to be an issue with 350-400 mA ???

  2. tecnolover2642 Says:

    Great video! You are amazing! My needs are the same as yours. I’d like more of a FLOOD type beam pattern. My question is: In your modded version what current draw did you acheive by changing out the R12 33ohm resistor?? 350, 400 mA?? Also, why did you put in a 47ohm ?? I thought you want a lower value resistor to get a higher current to the LED?? sorry, I’m not experienced in electronics but you said the low setting used the highest value resistor, so to incread the HIGH why use a lower?

  3. reddog694uk Says:

    WoW!! I just sat through all that vid. It kept me amazed and entertained probably because i use head lamps for work and my favourite is the Petzl Tikka XP Atex, I can’t wait for them to start using the xpg led, As i’m not confident enough to change it myself. But this guy is the biz, Well done!!

  4. THEtechknight Says:

    only suggestion i can offer is you gotta be carefull when increasing current because then you have to watch the switching transistors max ratings as far as current and power dissipation. exceed that, youll have a shorted transistor and a burned out LED. possibly backfed from the shorted transistor blowing the IC. been there, done that.

  5. Gameboygenius Says:

    19:15 – 19:55 Actually I’m guessing that they’re cutting the power at a low voltage to avoid deep discharge and consequently battery acid leakage.

  6. justinsn95 Says:

    Very nice video. Thanks for the nice tutorial on how to do this!

  7. eydryan Says:

    @chukchee your local electronics shop? you could always use those philips ones that are ultrabright, found some in my town that output 1440 lumens.

  8. eydryan Says:

    @enliteneer from what i understand voltage is constant at 3V. And intensity changes.

  9. eydryan Says:

    @slashfan1401 how hard can it possibly be to replace and LED… desolder wires; remove old LED; resolder wires :) )

  10. eydryan Says:

    Loved this Dave, perhaps one of your best videos yet mate! The whole hacking concept of it was a fun idea and watching the results and the process really made a lot of sense. Thanks a lot for sharing!

  11. 3rogueS Says:

    Brilliant, maybe not to this guy, but no doubt brilliant. As i love this headlamp as much as anyone, this video is a real treat.

  12. Afrotechmods Says:

    Great video. Power electronics is my crack.

  13. slashfan1401 Says:

    I wish you’d actually shown the act of replacing the LEDs, but that being said, this was a SUPERB video with loads of information, THANKS!!

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