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A recent Engineer in Wonderland post on the Electronic Weekly Electro-rambling blog mentioned developing an LED helmet for underground cave explorers.
Whereas 'Alice' backed away from this potentially life-critical project - imagine the potential consequences of failure in critical conditions - a reader emailed to flag their own successful builds. These were based a project described on Mine Explorer - see Miles's Homemade Cree Q5 LED Super Caplamp!
As the name suggests, it's based on the Cree Q5, which produces 230 lumens of light when consuming about 3.7 watts of power. As no headlamps were available based on the new emitter, Miles decided to build his own, and he says it wasn't particularly difficult or expensive to do, but there were impressive results.
He writes:A recent Engineer in Wonderland post on the Electronic Weekly Electro-rambling blog mentioned developing an LED helmet for underground cave explorers.
Whereas 'Alice' backed away from this potentially life-critical project - imagine the potential consequences of failure in critical conditions - a reader emailed to flag their own successful builds. These were based a project described on Mine Explorer - see Miles's Homemade Cree Q5 LED Super Caplamp!
As the name suggests, it's based on the Cree Q5, which produces 230 lumens of light when consuming about 3.7 watts of power. As no headlamps were available based on the new emitter, Miles decided to build his own, and he says it wasn't particularly difficult or expensive to do, but there were impressive results.
The Base Lamp
There is no point reinventing the wheel trying to make a lighting head from scratch, so I opted for a traditional mining caplamp to be the host for my project. Originally thinking of an Oldham head, I abandoned it instead for a Youle head of around 1950's vintage. They are larger than the Oldham heads so have more space inside for the wiring and circuitry, and the reflector is made of metal rather than the Oldhams plastic. This therefore can act as a useful heatsink for the mighty Q5 LED, which gets hot!
The Battery
The battery I made myself. I took an ABS plastic enclosure and inserted into it a 4.5ah 6v Sealed Lead Acid battery. This yields 27 watt-hours, so on full whack the Q5 should light for around 7 hours on this. I could have made a bigger one but I like the small enclosure and the light weight. I could have made a very small box with six or eight 18650 Lithium Ion cells but that would have put the project cost up. I could also have used a traditional Oldham battery (4v is fine) but charging it would have been the problem as the Youle head doesn't fit an Oldham charger.
Read Miles's Homemade Cree Q5 LED Super Caplamp!
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