Just incase you guys aren't aware. With your CT series bikes with magneto AC headlights, the lower the wattage the brighter the light. Talking here in NZ they had replaceable bulbs & probably came with a 25/25 6 volt that is. To go brighter we'd run a 20/20 or if you wanted t melt the tar seal & probably blow the bulb with big rev then go to 15/15 watt. We could getaway with 10/3 tail light as well but doubt its legal now. Our tail lights were magneto driven like the head & instrument illuminating bulbs. Stop light @ 10 watts was off the battery. Think originally ours had 21/5 in the tail--21 stop light. But anyway-- just sayin, lower wattage headlight or instrument illuminating gives brighter lights & also helps the battery get a little more charge too with lights on. Don't believe me--go try it guys. In saying that if a ac regulator has been fitted of a later IT series yamy or something then you'll be safe trying lower wattage bulbs without blowing them Only applies to replaceable bulb type but a sealed unit of original allowed wattage or 'less' wattage would be good & safe with regulator bulb saver. Hope that makes sense. Having trouble understanding it myself lol. I'm mainly referring to the guys above complaining of P/Poor lights on CT1--2--3's, or any magneto 6 volt lighting system really.

I had a chance to get out tonight in order to check out the brightness of the LED. It's pretty good but I may 'tip' the bucket up a bit . Now, if it's durable I'm all set!

I'm really impressed... and surprised that the LED works on AC.

My understanding is you would need much more current than that tiny battery could provide, and when your headlight is on all other lights would be much dimmer. Yamaha ran headlights off of the coil on the banshee twin 350s into the late 90s, but the banshee never had a battery to begin with. I'm sure someone around here has more than my highschool knowledge of electronics and can answer these questions, though.

Also, wattage of the light is the amount of energy it takes to produce a certain amount of light. So, if a 20w bulb claims x number of lumens, then when drawing 20w it will produce x lumens. It's your magneto's job to provide that wattage (thats why high revs = brighter lights.) If a 15w bulb produces x lumens as well, I believe it's simply more efficient. Regardless, your magneto obviously has less trouble providing 15w as apposed to 20w, so the bulb appears brighter.

I may be talking out of my ass on some of this, but that's how I believe it works.

A noble experiment has gone awry!

Well, I got 29 miles out of the LED then it gave up the ghost. I don't know if it was the unrectified AC power coming into it or the bulb itself. Perhaps I'll try another LED in conjunction with the rectifier and see what happens. It was very bright while it lasted!

Bummer.
Reminds me of the Lucas Electric slogan: "Get Home Before Dark!"

Lucas? Wasn't he the Prince of Darkness?!

Only until Ozzy Osborne came along .

You bad man - you've got me going down memory lane now!

Black Sabbath were the first band that I ever saw (Technical Ecstasy tour) and I was lucky enough to see him tour Blizzard of Ozz before Randy Rhoads' untimely death. What a guitarist.

Sorry, gone off topic (again!).

The Prince of Darkness! Brings me back to the days of my BSA's along with the '62 Triumph Herald and '59 Morris Mini Minor. Cool vehicles that wouldn't run in the rain.