I took antique lanterns and converted them to use modern CREE super bright leds, rechargeable batteries, and in-housing storage for solar cells. This all started when I discovered led emitters were only 75 cents OR $2 soldered onto an aluminum heat sink.
LARGE SOLAR LED LANTERN Found lanterns on ebay. Cree XP-G 105 Lumen CREEXPG-WW105 Warm-White 1-Up Indus Star LED 1x 5.5v 320mA Solar Cell 1x USB Charging Circuit 1x 6,600mAh 3.7V Lithium Ion Battery 1x 1N4001 Diode 1x Lithium Battery Charge Controller
Used a SP4T Potentiometer with resistors to reach the desired lumen settings. 1 - ON 2- 3.0V - 350mA - - 2.30ohms - 94 lumens 3- 3.2V - 700mA - .714ohms 4- 3.3V -1000mA - .400ohms
Resistor Value = Battery Voltage – LED Voltage / LED Current. So for me it was 3.6V-3.0V=0.6V, 0.6V/.350A = 2.3 ohm (96 lumens) Power Rating of Resistor = Battery Voltage – LED Voltage X LED Current For me this was 0.6V*.350A= .21Watts. You should use a resistor with a higher power rating for a safety factor.
SMALL SOLAR LED LANTERN Neutral-White Luxeon LXM3-PW51-90 Rebel Emitter 1x 6V 80mA Solar Cell 3x 1.4V NiMh rechargeable batteries wired in series 1x 1N914 Diode
4.2V-3.0V=1.2V, 1.2V/.350A = 3.40ohm (90 lumens)
Solar Cell connects via 2.5mm jack and stores in lantern. Cell has magnets added to the back to that it is held in desired location (lantern top) while charging.
Ryan
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