I forgot about rectifying! Yes, looks like I need six half-watt LED's instead of one 5W. Are there any white LEDs unhappy with ac that I need to be wary of?
Don't have enough magnets to double up, but I can reduce the gap a little and get 2V/coil @ 1100 rpm, 6.8 volts/leg switching to star. That gives a 600 rpm cut-in instead of 1100. Looking around, some of the smaller half watt leds have lower voltage that the luxeon, like about 3.2V instead of 3.5V. That drops it to about 500rmp cut-in, assuming the leds are happy with AC.
A little off topic, but what's the best way to reduce rectifier losses? I noticed that schottky diodes have low losses when partially loaded (.3V @ 1/10th load, .6V at full load, for example). Do all rectifier diodes exhibit a lower voltage loss at partial loads or is that a schottky thing? Looking through digikey data sheets looks like low voltage/high amperage schottkys have the lowest voltage drop. Is that a valid technique to reduce losses; oversize the amperage capacity but not the voltage rating?
