Completion of Lighting

Yeovil

I planned on using three LEDs as my total loading, but my battery configuration giving 10 volts output meant that my boost converter would go into direct drive when I reduced the power output if I only used three! Even though it turned it down to 350 milliamps I required even further reduction to enable me to have an emergency lighting situation, for example if I chose to cycle through the night even though my 3 W Hub dynamo would be boosting the batteries one bank at a time switchable.So I decided to bring four lights into the equation, with a small amount of testing this proved to be the answer to my battery configuration, using the trim pot I could then drop the output to about 70 milliamps which by the way was still brighter than the original lighting system.The forward voltage from memory as I believe 2.7 volts minimum, so for approximation four times 2.7 equals 10.8 volts... 10.8 volts at 70 milliamps equals about threequarters of a Watt total for the four LEDs at a minimum power level, fully sustainable as the Hub dynamo is rated at 3 WFurther testing produced:-With 4 x Seoul p4 in series using 8 AA NIMH IN SERIES led current 0.710 amps led total volt drop 13.22 = 9.3862 wattsbatt current 1.15 amps at 9.2 volts = 10.4926 wattsefficiency = 89.455 led current 0.350 amps led total volt drop 12.53 = 4.3855 wattsbatt current 0.49 amps at 9.82 volts = 4.81 wattsefficiency = 91.18Set up with two switches four power levels shorted lowest open circuit highestplus two resistors for intermediate power, four seoul p4's flashed up on high from low quite impressive!!Well pleased with the Fatman thanks George.