I am looking to put a LED taillight on a '78 Honda XL250S to get a bit brighter of a light out back for night driving... I am not running a battery and it is a 6 volt system... It seems like all the LED tail lights are 12 volt but with the low amp draw of LED it seems like it should be workable. Anybody know what I would need to do to make this work?
superbrightleds sells 1157 volt bulbs in 6, 12, and 24 V versions http://www.superbrightleds.com/more...ulbs/1157-led-bulb-dual-intensity-19-led/508/
No, it would apply 6 volts on each if 12 volt were applied to each end. They'd be dimmer, but it'd work.
umm....no...the OP said his bike has a 6 volt system and you said to use two 12 volt LED bulbs in series...if that were done each bulb would only see 3 volts and would not work at all. If you meant to wire two 12 volt bulbs in parallel that would not work in a 6 volt system either.
I found the OP's question interesting, as I have an 83 XR500 with a 6 volt system. The OP is looking for more brightness by using an LED bulb, but the superbrightleds 6 volt bulb is 19 lumens. A standard incandescent 6 volt bulb is 21 lumens (a standard 12 volt 1157 is 32 lumens). Things are better in the 12 volt LED area, where 60 to 140 lumen bulbs are available. It looks like a 6 volt LED bulb will be a bit dimmer than the incandescent, but I think it would be more vibration-proof.
hmmm, interesting! they do have choices on color, a red bulb might be more visible than white through the lens. Also this guy sells complete 6 volt LED lightboards to fit within taillights, could go with that or build something similar http://www.norbsa02.freeuk.com/goffyleds.htm
The light that is on there from the last owner is a single filament marker light that is very small. Even though the LED has 2 less lumens, it is projected in a 15 degree path so I think it will project better than an incondesent that is 2 lumens brighter but puts the light out in every direction. I was also thinking the LED may keep the light brighter at idle with its low amp draw since I am not running a battery.
Another thing to consider: If you use a red or amber or any other coloured lens with a white incandescant you will block all the light that isn't the right wavelength(s) so not all the lumens will be radiated. LED lights through clear lenses radiate close to 100%.
It should be added that both Paul Goff and Superbright LED sell stop/tail solutions that radiate red light rearwards and white light downwards, so your local official pedant can't nail you for inadequate number plate illumination.
I installed a 12 volt LED 1157 board type tail light (red LED bulbs) in my 85 Yamaha TT600N, no battery. Normal voltage with the magneto is to run between 7 and 17 volts. After two years of riding I have had no problems with the lamp. It seems to almost at bright at idle as at high RPM's. To mount the circuit board I cut a wedge of wood, using hot melt glue I secured the wedge to the back of the light assembly, plugged in the 1157 socket which I glued below the LED circuit board. I than glued the circuit board to the wedge of wood. So far it has stayed together for 2 years of trail riding with out the hot melt glue coming loose. Before the conversion to LED lamp I was burning out an 12 volt 1157 lamp every time I rode the bike. LED are very forgiving for incoming voltage. I like the LED board in the Yamaha so much I converted my 95 R100GS to LED. Removed the old plastic chrome plated (most of the chrome had flaked off) reflector and install a wooden shim and glued it together. Around 5000 miles and it is still in place and working. I do have one white LED point down on the plate. If I was going to make the conversion again I would install three white for plate illumination. One works but three would work better.
