Comments on: EEVblog #67 – Hacking the Princeton Tec EOS LED Headlamp with a Cree XPG http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/ No Script, No Fear, All Opinion Fri, 10 Feb 2012 14:30:20 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: cda http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-69382 cda Tue, 21 Jun 2011 12:29:10 +0000 http://www.eevblog.com/?p=599#comment-69382 Nice blog! How does the modified headlamp behave on the long run ? (batteries last the same? no heat problems for longer usage?) Nice blog! How does the modified headlamp behave on the long run ? (batteries last the same? no heat problems for longer usage?)

]]> By: Paul http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-67447 Paul Thu, 17 Mar 2011 18:09:50 +0000 http://www.eevblog.com/?p=599#comment-67447 Did you consider that a better buck converter would be worse? A "perfect" converter would maintain full light output untill you are somewhere halfway a trip in a dark cave and then suddenly die completely. An even better converter (such as this one) would keep an even light output untill the bateries are almost flat and then slowly get dimmer. And you'll think "Well, I didn't get as much light on my last trip, maybe I'll put some fresh bateries in it. It also would have been nice if you did a measurement on the sleep current. The headlight I use has a real on/off switch and I use it on about 2 or 3 trips per year. I think I replaced the bateries only once in the 5 to 7 years I have this light. Did you consider that a better buck converter would be worse?

A “perfect” converter would maintain full light output untill you are somewhere halfway a trip in a dark cave and then suddenly die completely.

An even better converter (such as this one) would keep an even light output untill the bateries are almost flat and then slowly get dimmer. And you’ll think “Well, I didn’t get as much light on my last trip, maybe I’ll put some fresh bateries in it.

It also would have been nice if you did a measurement on the sleep current. The headlight I use has a real on/off switch and I use it on about 2 or 3 trips per year. I think I replaced the bateries only once in the 5 to 7 years I have this light.

]]> By: EEVblog http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7829 EEVblog Mon, 29 Mar 2010 06:09:04 +0000 http://www.eevblog.com/?p=599#comment-7829 I didn't bother, I just the whole assembly sit loose in the housing. The battery door takes care of holding it all in place, and it doesn't really pop out when I open it. Dave. I didn’t bother, I just the whole assembly sit loose in the housing. The battery door takes care of holding it all in place, and it doesn’t really pop out when I open it.

Dave.

]]> By: EEVblog http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7828 EEVblog Mon, 29 Mar 2010 06:07:12 +0000 http://www.eevblog.com/?p=599#comment-7828 No change to the reflector. I've modded both and old and new model and both gave very similar wide beam patterns. Then lens was obviously closely matched to the original LED shape and pattern. The XPG has a different shape and pattern, so obviously is not as effective with the original lens, but I do like the resultant pattern. No change to the reflector. I’ve modded both and old and new model and both gave very similar wide beam patterns. Then lens was obviously closely matched to the original LED shape and pattern. The XPG has a different shape and pattern, so obviously is not as effective with the original lens, but I do like the resultant pattern.

]]> By: David http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7719 David Thu, 25 Mar 2010 15:27:00 +0000 http://www.eevblog.com/?p=599#comment-7719 Dave, Did you do anything to the original reflector to get that flood...ish beam pattern? Was that an older design of headlamp or the newer more diffused style lens? Cheers Dave,

Did you do anything to the original reflector to get that flood…ish beam pattern? Was that an older design of headlamp or the newer more diffused style lens?

Cheers

]]> By: David http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7718 David Thu, 25 Mar 2010 15:26:40 +0000 http://www.eevblog.com/?p=599#comment-7718 Dave, Did you do anything to the original reflector to get that floodish beam pattern? Was that an older design of headlamp or the newer more diffused style lens? Cheers Dave,

Did you do anything to the original reflector to get that floodish beam pattern? Was that an older design of headlamp or the newer more diffused style lens?

Cheers

]]> By: jeremy http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7661 jeremy Tue, 23 Mar 2010 13:03:31 +0000 http://www.eevblog.com/?p=599#comment-7661 One other trick that they designed into the thumbscrew: the buckle on the headband is the perfect size for turning the screw. No need for a screwdriver! (and I remember reading somewhere that this was on purpose, not just a coincidence) One other trick that they designed into the thumbscrew: the buckle on the headband is the perfect size for turning the screw. No need for a screwdriver! (and I remember reading somewhere that this was on purpose, not just a coincidence)

]]> By: Murphy http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7645 Murphy Mon, 22 Mar 2010 18:10:31 +0000 http://www.eevblog.com/?p=599#comment-7645 So what do you do to replace those welded plastic things? Epoxy? Hot glue? New plastic? Those have always bothered me. So what do you do to replace those welded plastic things? Epoxy? Hot glue? New plastic? Those have always bothered me.

]]> By: Dan http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7575 Dan Fri, 19 Mar 2010 21:39:12 +0000 http://www.eevblog.com/?p=599#comment-7575 Great blog but you missed one of the best design features of this light. The adjustment bracket on the headband is designed to be used as a screw driver for loosening the thumb screw on the battery compartment. How cool is that. Great blog but you missed one of the best design features of this light. The adjustment bracket on the headband is designed to be used as a screw driver for loosening the thumb screw on the battery compartment. How cool is that.

]]> By: Luke http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7571 Luke Fri, 19 Mar 2010 16:31:46 +0000 http://www.eevblog.com/?p=599#comment-7571 The cutting edge, most efficient LEDs always have quite a cool white tint. As the technology matures they add neutral and warm white tints. The XP-G is known to range between bluish white and greenish white currently, although the neutral and warm variants are on their way! The cutting edge, most efficient LEDs always have quite a cool white tint. As the technology matures they add neutral and warm white tints. The XP-G is known to range between bluish white and greenish white currently, although the neutral and warm variants are on their way!

]]> By: Robert http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7481 Robert Tue, 16 Mar 2010 11:52:27 +0000 http://www.eevblog.com/?p=599#comment-7481 Thanks for a good answer Jim and Erik! I look it up more on google now that I now the right name for it.. :) Thanks for a good answer Jim and Erik! I look it up more on google now that I now the right name for it.. :)

]]> By: EEVblog http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7466 EEVblog Tue, 16 Mar 2010 04:06:19 +0000 http://www.eevblog.com/?p=599#comment-7466 Thanks for the support Hoak. Yes, the video blog takes up more time than I originally thought it would, and it would probably be almost a full time job if I actually put more effort into it. i.e. actually prepare and write scripts and material, and took care in filming, presentation, and editing etc instead of my current off-the-cuff approach. Dave. Thanks for the support Hoak.
Yes, the video blog takes up more time than I originally thought it would, and it would probably be almost a full time job if I actually put more effort into it. i.e. actually prepare and write scripts and material, and took care in filming, presentation, and editing etc instead of my current off-the-cuff approach.

Dave.

]]> By: Hoak http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7426 Hoak Sun, 14 Mar 2010 08:22:48 +0000 http://www.eevblog.com/?p=599#comment-7426 I love Dave's Videos Blogs and agree this episode definitely among the 'best of' -- probably because it's both accessible and of value to wider audience. Dave is among a very small minority of people creating Video Blogs that are actually worth watching: he's well qualified with respect to what he's talking about; and his enthusiasm and presentation are fantastic -- I'm surprised networks haven't discovered him yet. The amount of time and effort that goes in to making a Video Blog is no small thing, I hope others appreciate how much goes into this. Dave reminds me of some of my best Teachers and Professors that made paying for a very expensive education worthwhile; I'd be donating to his show if I was currently employed! I love Dave’s Videos Blogs and agree this episode definitely among the ‘best of’ — probably because it’s both accessible and of value to wider audience.

Dave is among a very small minority of people creating Video Blogs that are actually worth watching: he’s well qualified with respect to what he’s talking about; and his enthusiasm and presentation are fantastic — I’m surprised networks haven’t discovered him yet.

The amount of time and effort that goes in to making a Video Blog is no small thing, I hope others appreciate how much goes into this.

Dave reminds me of some of my best Teachers and Professors that made paying for a very expensive education worthwhile; I’d be donating to his show if I was currently employed!

]]> By: BillyG http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7388 BillyG Fri, 12 Mar 2010 19:46:38 +0000 http://www.eevblog.com/?p=599#comment-7388 Dude, do you always write some blabber like this every time you see a post you don't like? Sheesh, looks like someone has breathed in too much zinc chloride at the bench. Dude, do you always write some blabber like this every time you see a post you don’t like? Sheesh, looks like someone has breathed in too much zinc chloride at the bench.

]]> By: Michael Thompson http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7387 Michael Thompson Fri, 12 Mar 2010 16:28:48 +0000 http://www.eevblog.com/?p=599#comment-7387 WOW Nice job! I love hardware hacking, and when I saw what you were doing I had to check it out. Man, what excellent results too! A more even and "floody" kind of light really is much more useful in more generalized outdoor situations and this does the trick! Add to that perfectly logical reasons to own more meters and this whole thing is just absolute WIN! As always you rock, Dave! WOW Nice job!

I love hardware hacking, and when I saw what you were doing I had to check it out.

Man, what excellent results too!
A more even and “floody” kind of light really is much more useful in more generalized outdoor situations and this does the trick!

Add to that perfectly logical reasons to own more meters and this whole thing is just absolute WIN!

As always you rock, Dave!

]]> By: GuShH http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7368 GuShH Fri, 12 Mar 2010 00:10:42 +0000 http://www.eevblog.com/?p=599#comment-7368 I'm looking forward to more entries per week and Dave sharing more tips, perhaps starting a few community projects as well. There are some interesting fellas around eevblog, so it wouldn't go to waste at all. I’m looking forward to more entries per week and Dave sharing more tips, perhaps starting a few community projects as well. There are some interesting fellas around eevblog, so it wouldn’t go to waste at all.

]]> By: GuShH http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7367 GuShH Fri, 12 Mar 2010 00:08:44 +0000 http://www.eevblog.com/?p=599#comment-7367 Clearly LED technology is way over your head buddy. You're ignorant, at best. The point of this blog entry is to share a thought or two on consumer products, personal choice and how to enhance them should you need to, theres no holy grail -- you're expecting too much from a blog, clearly you need to get out more and live -- theres a world out there, experience it for once. Jeez... Clearly LED technology is way over your head buddy. You’re ignorant, at best.

The point of this blog entry is to share a thought or two on consumer products, personal choice and how to enhance them should you need to, theres no holy grail — you’re expecting too much from a blog, clearly you need to get out more and live — theres a world out there, experience it for once.

Jeez…

]]> By: Nico http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7359 Nico Thu, 11 Mar 2010 19:58:23 +0000 http://www.eevblog.com/?p=599#comment-7359 Awsome blog. I love you 'teaching' blogs in the sense of when you explain stuff and why you think it was designed as it is, it's pros and cons etc... This is so useful especially if you do electronics mainly as a hobby and not as a professinonal. Thanks Awsome blog.
I love you ‘teaching’ blogs in the sense of when you explain stuff and why you think it was designed as it is, it’s pros and cons etc…
This is so useful especially if you do electronics mainly as a hobby and not as a professinonal.
Thanks

]]> By: Maverick http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7357 Maverick Thu, 11 Mar 2010 19:19:14 +0000 http://www.eevblog.com/?p=599#comment-7357 If your into this sort of modding you should check the candle power forums. Its a forum of flashlight nerds who do nothing but this sort of thing and I really do mean nothing but. If your into this sort of modding you should check the candle power forums. Its a forum of flashlight nerds who do nothing but this sort of thing and I really do mean nothing but.

]]> By: Eric http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7334 Eric Thu, 11 Mar 2010 03:52:50 +0000 http://www.eevblog.com/?p=599#comment-7334 Can you put up a white board shot on how you chose your resistors? Fantastic video! I love when you show me how to do something or explain a design. Can you put up a white board shot on how you chose your resistors?
Fantastic video! I love when you show me how to do something or explain a design.

]]> By: Eric http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7333 Eric Thu, 11 Mar 2010 03:25:31 +0000 http://www.eevblog.com/?p=599#comment-7333 Yeah, Like Jim said, instead of packaging the chip on a surface mount or dip package, it's packaged under that blob on the board. This cuts out the middle man when you're making a million of something. Yeah, Like Jim said, instead of packaging the chip on a surface mount or dip package, it’s packaged under that blob on the board. This cuts out the middle man when you’re making a million of something.

]]> By: pghpete http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7332 pghpete Thu, 11 Mar 2010 02:01:21 +0000 http://www.eevblog.com/?p=599#comment-7332 @eraser Wow. How did I not make that connection!? DOH! @eraser Wow. How did I not make that connection!? DOH!

]]> By: Eraser http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7331 Eraser Thu, 11 Mar 2010 01:38:46 +0000 http://www.eevblog.com/?p=599#comment-7331 @pghpete The hackaday article links back to EEVblog... @pghpete

The hackaday article links back to EEVblog…

]]> By: UrbanMonkey http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7329 UrbanMonkey Thu, 11 Mar 2010 01:00:38 +0000 http://www.eevblog.com/?p=599#comment-7329 Looking forward for more blogs like this one. Something a little more technical would be nice as well. Looking forward for more blogs like this one.

Something a little more technical would be nice as well.

]]> By: pghpete http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7328 pghpete Thu, 11 Mar 2010 00:14:11 +0000 http://www.eevblog.com/?p=599#comment-7328 Dave, This is something I thought you would be interested in... I also would like to know if it really would work. Perhaps you should try it! :) http://hackaday.com/2010/03/10/50mhz-to-100mhz-scope-conversion/ Regards, pghpete Dave,

This is something I thought you would be interested in… I also would like to know if it really would work. Perhaps you should try it! :) http://hackaday.com/2010/03/10/50mhz-to-100mhz-scope-conversion/

Regards,
pghpete

]]> By: pghpete http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7327 pghpete Wed, 10 Mar 2010 23:49:15 +0000 http://www.eevblog.com/?p=599#comment-7327 @billyg Nice try, troll @billyg Nice try, troll

]]> By: Jim http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7322 Jim Wed, 10 Mar 2010 20:58:38 +0000 http://www.eevblog.com/?p=599#comment-7322 Robert, The device under the 'blob' is a bare chip wire bonded direct to the PCB. See for example http://www.tutorialsweb.com/smt/smd-components/chip-on-board.htm Google "Chip on Board" for more information. Jim Robert,
The device under the ‘blob’ is a bare chip wire bonded direct to the PCB.

See for example http://www.tutorialsweb.com/smt/smd-components/chip-on-board.htm

Google “Chip on Board” for more information.

Jim

]]> By: BillyG http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7319 BillyG Wed, 10 Mar 2010 18:22:51 +0000 http://www.eevblog.com/?p=599#comment-7319 Another lame video from Dave. tsk tsk. LEDs? WTF man, this place is turning into hackaday. First dave was crushing on the arduino, then he shilled for microchip pic products. Now he's playing with LEDs. It's all down hill from here. Most people would spill a little bit from a 40Oz bottle of malt liquor for all the dead homies, dave would just pull the leds out his bug box and stick them in a block of cheddar cheese. Another lame video from Dave. tsk tsk. LEDs? WTF man, this place is turning into hackaday. First dave was crushing on the arduino, then he shilled for microchip pic products. Now he’s playing with LEDs. It’s all down hill from here.

Most people would spill a little bit from a 40Oz bottle of malt liquor for all the dead homies, dave would just pull the leds out his bug box and stick them in a block of cheddar cheese.

]]> By: Pjn http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7316 Pjn Wed, 10 Mar 2010 16:33:52 +0000 http://www.eevblog.com/?p=599#comment-7316 If you are interested in very wide beam headlamps/flashlights (120 If you are interested in very wide beam headlamps/flashlights (120

]]> By: Adam http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7315 Adam Wed, 10 Mar 2010 16:24:10 +0000 http://www.eevblog.com/?p=599#comment-7315 Awesome, this was most informative. Please do more like these. Awesome, this was most informative. Please do more like these.

]]> By: John R http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7313 John R Wed, 10 Mar 2010 13:55:40 +0000 http://www.eevblog.com/?p=599#comment-7313 The XP-Gs are only just becoming available in warm/neutral white colours. The XP-Gs are only just becoming available in warm/neutral white colours.

]]> By: Robert http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7310 Robert Wed, 10 Mar 2010 11:27:11 +0000 http://www.eevblog.com/?p=599#comment-7310 Nice episode! :) I have a question thought, I've always wondered about these on chip ICs that looks like they are melted onto the board. Are they "normal" surface mounted ICs under there? Do they use a standard PIC,AVR,MSP430 under there or is that some ASIC? Nice episode! :)

I have a question thought, I’ve always wondered about these on chip ICs that looks like they are melted onto the board.

Are they “normal” surface mounted ICs under there? Do they use a standard PIC,AVR,MSP430 under there or is that some ASIC?

]]> By: Todd Harrison http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7309 Todd Harrison Wed, 10 Mar 2010 11:07:13 +0000 http://www.eevblog.com/?p=599#comment-7309 Dave, Best blog yet! I love taking things apart to see how they work and then learning how to mod it to my own liking. You MUST do more of these videos showing your evaluation of the how the circuits work and how to measure and mod things. SUPER! Dave,
Best blog yet! I love taking things apart to see how they work and then learning how to mod it to my own liking. You MUST do more of these videos showing your evaluation of the how the circuits work and how to measure and mod things. SUPER!

]]> By: pluto http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7300 pluto Wed, 10 Mar 2010 04:58:58 +0000 http://www.eevblog.com/?p=599#comment-7300 tom, my guess is a simple FET for reasons of efficiency tom, my guess is a simple FET for reasons of efficiency

]]> By: webkraller http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7298 webkraller Wed, 10 Mar 2010 04:24:14 +0000 http://www.eevblog.com/?p=599#comment-7298 I noticed that as well, although it'd hard to tell from this recorded footage what "actual white" is since we don't have a metric for the camera's white balance. Great vid! It's always exciting to see a product reverse engineered. I noticed that as well, although it’d hard to tell from this recorded footage what “actual white” is since we don’t have a metric for the camera’s white balance.

Great vid! It’s always exciting to see a product reverse engineered.

]]> By: Sean http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7297 Sean Wed, 10 Mar 2010 03:46:21 +0000 http://www.eevblog.com/?p=599#comment-7297 I like those cree xpg leds and you should give me one. Is it just me though or did the old leds have a more neutral white compared with the cree xpg's bluish fringe when you were showing them on the wall. I like those cree xpg leds and you should give me one. Is it just me though or did the old leds have a more neutral white compared with the cree xpg’s bluish fringe when you were showing them on the wall.

]]> By: Carl http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7291 Carl Wed, 10 Mar 2010 00:01:49 +0000 http://www.eevblog.com/?p=599#comment-7291 I have to say this is my favourite blog so far, I really like the concept of taking a product finding out how it works and improving it. Although more details on the actual mod would've been great it was an enjoyable watch and I hope to see more like this in the future. Thanks Dave keep up the good work :D I have to say this is my favourite blog so far, I really like the concept of taking a product finding out how it works and improving it.

Although more details on the actual mod would’ve been great it was an enjoyable watch and I hope to see more like this in the future.

Thanks Dave keep up the good work :D

]]> By: Mark H http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7285 Mark H Tue, 09 Mar 2010 23:32:19 +0000 http://www.eevblog.com/?p=599#comment-7285 Ack! You didn't show the mod. What actual resistor value did you use on the high beam? Ack! You didn’t show the mod. What actual resistor value did you use on the high beam?

]]> By: Tom http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7284 Tom Tue, 09 Mar 2010 23:31:22 +0000 http://www.eevblog.com/?p=599#comment-7284 You draw bipolar transistors but you refer to the gate. What kind of transistor do you actually think it is? Would a synchronous converter actually be more efficient than a diode when using bipolar transistors? You draw bipolar transistors but you refer to the gate.
What kind of transistor do you actually think it is?
Would a synchronous converter actually be more efficient than a diode when using bipolar transistors?

]]> By: jon http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7283 jon Tue, 09 Mar 2010 23:29:30 +0000 http://www.eevblog.com/?p=599#comment-7283 What happened before 22:01 Dave? You suddenly look either a bit distraught or just plained knackered. What happened before 22:01 Dave? You suddenly look either a bit distraught or just plained knackered.

]]> By: EEVblog http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7282 EEVblog Tue, 09 Mar 2010 23:16:06 +0000 http://www.eevblog.com/?p=599#comment-7282 http://www.cutter.com.au/ http://www.cutter.com.au/

]]> By: Zach http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/comment-page-1/#comment-7281 Zach Tue, 09 Mar 2010 22:52:46 +0000 http://www.eevblog.com/?p=599#comment-7281 Where do you buy the cree leds? Where do you buy the cree leds?

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