Transcript Stuart France LED Lamp

Taking a White LED
Lamp Forward
Stuart France
The 1998 version
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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?
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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
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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