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Taking a White LED Lamp Forward. Stuart France. The 1998 version. 24 Nichia 5mm white LEDs Current controlled DC-DC step-up Oldham or CEAG headpiece Continuously variable brightness knob or 2-position pilot-main setting 3 x NiMH 18650 battery in Petzl box
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Taking a White LED Lamp Forward Stuart France
The 1998 version • 24 Nichia 5mm white LEDs • Current controlled DC-DC step-up • Oldham or CEAG headpiece • Continuously variable brightness knob • or 2-position pilot-main setting • 3 x NiMH 18650 battery in Petzl box • originally 6 volt Kirby kidney pack on lead
Has anything happened in the past 10 years? • Microprocessors costing 50p • Software seen as an asset not a risk • Battery technology advances • Powerful single die white LEDs • Lenses for the above • LED torches become consumer item
Updating the lamp spec • 3 x 3W Cree modules run at 2W (from Tesco) • 3 x P4 in triple lens dichroic unit also possible • Push-button on-off • Brightness knob • Current controlled step-up to about 10 volts • Microprocessor for: • Power on/off function • Battery voltage measurement • Battery state LED signalling • Green, green-red, red, flash main beam, force off, when: • 100-50%, 49-20%, 20-10%, 10-0%, 0% left
CEAG caplamp shell • Totally waterproof • no charger keyway, no rotary switch • IP68 push button, IP68 brightness knob • IP68 metal cable gland, siliconed inside • Tall bezel for dichroic lamp modules • Black sleeve to stop scatter • Nitrile rubber o-ring
Li-ion battery pack • Two 18650 cells, nominal 8V 2.5AH • Off the shelf £20 charger from CPC • Metal battery box, ends sealed with PU • Over-current cut-out • Two pin connector • spare line socket acts as a blanking plug • Attaches with super-velcro to flat area cast on rear of helmet
Push Button • 3-second push to power on or off • Bicolour LED in middle shows for 15 secs after power off to indicate battery level • visible in cave when reflected off a hand
Brightness knob • Gives 6-to-1 power ratio • Suits small and large passages
Software • PIC12F675-04I/P (DIL8 package) • Easily reworked for other battery types • Battery monitoring can be disabled by jumper which allows any battery <10 volts to be used in an emergency • It will then deep discharge a Li-ion pack, and ruin it, but extract all the energy