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  \___ \ | '_ \ | | / __|| |/ / / _ \| '__|/ __|| '_ \  / _ \ / _ \  |_ \
   ___) || | | || || (__ |   < |  __/| |   \__ \| | | ||  __/|  __/ ___) |
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Snickersnee3: Aaron Benoy's DIY Current-Regulated 3-Watt LED Caving Headlamp
I needed a dimmable hands-free primary light that was very bright, had a
wide beam pattern, a very long runtime and cost less than $100. Since no
commercially-available headlamp fit the bill, I made my own. You can too.
This is how it'll look in the end (except you'll solder better than I do):
Polyptych of the Snickersnee3 3W LED Headlamp by Aaron Benoy. Thumbnail. Beam pattern at 1 meter of the Snickersnee3 3W LED Headlamp by Aaron Benoy. Scale in imperial and SA units. Thumbnail. Dyptych of the Snickersnee3 3W LED Headlamp circuit (disregard horrid soldering job). Thumbnail.
Allow me to address all you'll need to know to make one yourself, provided you're willing to try some elementary soldering, reading a really simple schematic (below), and ordering a few parts from the Mouser catalog. You can't do much worse than I did. Snickersnee3 schematic:  Schematic for the Snickersnee3 3W LED Headlamp by Aaron Benoy. Thumbnail. Got it? Here's your shopping list; many of these parts will be cheaper when you get around to ordering them than their price when this was written. In most circumstances and lunar phases, the Mouser catalog will be the least expensive supplier, but don't let that dissuade you from shopping around. US$ 3.03 Aavid Thermaloy TO-3 Heatsink 568403b00000 1.50 Carclo Circular LED Optic Holder 10012 2.90 Eagle Plastic Devices Project Enclosure 400-1541 3.99 Fraen Low-Profile 20mm 30° Lens FLP-HMB3-LL01-0 2.44 (4x) Keystone Densi-Pak 2AA Covered Battery Holders 2490 24.99 LEDdynamics 3021 Wide Range Power Module 3021-D-I-1000 8.75 Lumileds Luxeon III Lambertian LED LXHL-LW3C 1.60 (4x) Molex 5mm 2-Position PCB Terminal Blocks 39840-0102 3.30 Molex HCS-125 2-Circuit Plug & Receptacle 03-12-2026 3.30 NKK Miniature SPST Toggle Switch M2011SS1W01 1.79 Radio Shack Dual Mini Board 276-148 5.98 Vishay/Sfernice Cermet 5KΩ Potentiometer P16NP-5K-10-A ----- US$ 63.57 cost to build (helmet not included).
So, how does the Snickersnee3 measure up to other Luxeon LED headlamps? +---------------+--------+---------------+------+---------+----+------+----+ |LEDHeadlampName|HowBrite|Full/ExtRuntime| MTBF |Batteries|Dim?|Regul?|Cost| +---------------+--------+---------------+------+---------+----+------+----+ |ActionLight100 | /100Lm| 0.3h 480.0h | 500h|2x CR123A| y | y |$240| |Krem |5W/120Lm| | 500h|4x AA | y | y |$ 70| |Nova |5W/120Lm| 3.5h 20.0h | 500h|1x FX-ion| y | y |$350| |SS Procedure |5W/120Lm| n/a 1.0h | 500h|1x 72250 | NO | NO |$685| +---------------+--------+---------------+------+---------+----+------+----+ |Snickersnee3 |3W/ 80Lm| 24.0h 72.0h |20000h|8x AA | y | y |$ 64| +---------------+--------+---------------+------+---------+----+------+----+ |2630 HeadsUP |1W/ 30Lm| 3.0h 24.0h |10000h|3x AA | y | y |$ 60| |Argo |1W/ 30Lm| 1.0h 6.5h |10000h|3x AAA | y | y |$ 60| |Cyba-LiteXtreme|1W/ 30Lm| 7.0h 14.0h |10000h|3x AA | y | y |$ 64| |ECO |1W/ 30Lm| 15.0h 96.0h |10000h|4x AA | y | NO |$ 80| |EOS |1W/ 30Lm| 6.5h 57.3h |10000h|3x AAA | y | y |$ 39| |PrimeLite A |1W/ 30Lm| n/a 15.0h |10000h|3x AA | NO | NO |$ 79| |Yukon HL |1W/ 30Lm| n/a 35.0h |10000h|3x AA | NO | NO |$ 60| |Zenix |1W/ 30Lm| n/a 15.0h |10000h|3x AAA | NO | NO |$ 45| |Zenix IQ |1W/ 30Lm| 8.0h 30.0h |10000h|2x AA | y | y |$ 48| +---------------+--------+---------------+------+---------+----+------+----+
(Read blanks as unknown; underlines the worst and bold the best. Note that all commodity batteries are considered equal and proprietary battery packs are considered lame; both represented here are expensive and won't come with a charger. I don't appreciate vendor lock-in.)
And a very unfair comparison with conventional incandescent flashlights...
+---------------+--------+---------------+------+---------+----+------+----+ |Benchmark Light|Bulb/Lm |Full/ExtRuntime| MTBF |Batteries|Dim?|Regul?|Cost| +---------------+--------+---------------+------+---------+----+------+----+ |C2 Centurion |Xe/ 65Lm| n/a 1.0h | |2x 123A | NO | NO |$101| |Economy Bright |PR/ 10Lm| n/a | |2x D | NO | NO |$ 1| |M6 |Xe/ 74Lm| n/a 1.0h | 120h|2xCR123A | NO | NO |$ 67| |MagLite 2D |Kr/ 18Lm| n/a 10.0h | 36h|2x D | NO | NO |$ 30| |MagLite 3D |Kr/ 39Lm| n/a 10.0h | 36h|3x D | NO | NO |$ 31| |MagLite 4D |Kr/ 59Lm| n/a 10.0h | 36h|4x D | NO | NO |$ 32| |Mini Maglite AA|Kr/ 5Lm| n/a 6.0h | |2x AA | NO | NO |$ 16| +---------------+--------+---------------+------+---------+----+------+----+ |Snickersnee3 |3W/ 80Lm| 24.0h 72.0h |20000h|8x AA | y | y |$ 64| +---------------+--------+---------------+------+---------+----+------+----+ Summary: The clear conclusion here is that anyone with a whit of industriousness can create a regulated, dimmable 3-Watt light for hands-free applications that:If you build one, drop me a line and let me know how it goes! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Appendix:
  1. This is a hack. I assure you I have no idea what I'm doing.
  2. This project is not for sale, and I would feel strange building to order because I am an abject amateur. If you don't have the appropriate hacker ethic to figure this out, show this design to any two-bit electrician who should be elated to part you from your money.
  3. If 8xAA isn't what you'd like to have on your head, you can use almost any combination of batteries you like. The 3021-D-I-1000 can take anything from 5VDC to 32VDC!
  4. If you simply must have the newest white Luxeon V Portable LXHL-LW6C, by all means go ahead. Bear in mind, however, that you'll be paying 130% more for a light that is only 50% brighter, requires 50% more heatsinking (24in2!), and will need to be replaced after 500 hours; 40 times sooner than the LXHL-LW3C. Also please note that the the 3021-D-I-1000 is not an appropriate power module for the LXHL-LW6C as it cannot be driven more than 700mA; use the 3021-D-I-750 instead.
  5. I challenge all the unabashed measurebators out there to check out the new BL-3000 LED arrays from Lamina Ceramics. As of this writing, no LED light remotely approaches their output of 570Lm! I have no information on their thermal management, but at the power they require (11.3VDC/26W for 5500°K, or 24VDC/28W for 4300°K) it will likely mean a pretty big heatsink. Nor for that matter do I know their MTBF, but it appears that they are burning the candle at both ends (so to speak).
  6. The design of Snickersnee3 is far too simple to patent. You may build it, change it in any way and not credit me, mock the design from the highest point in the village and burn it in effigy. The absolutely concrete demarcation is that this webpage and images are copyrighted!
  7. All necessary care was taken to safeguard the correctness and completeness of the statements made herein. It cannot be excluded that some mistakes have occurred. If you spot one, let me know.
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              (c)2004, 2005 Aaron Benoy. Violate at your peril.