Hi All.
I picked up a LED tail , brake light from ebay, tried it on the bike that is wired for positive earth ,no go, I then check the light on the battery , same no go when using positive earth but when I switched polarity they worked.
Does any one know how I can fix this LED light to run positive earth and work.
Cheers Drew

No LED's are earth sensitive. I don't know what bike you have, but an M20 should be Neg earth. If you have a bike with a dynamo and standard regulator (not electronic) its very simple to reverse the polarity to Neg earth......Just ask. I've just done the same on an M20 that was erroneously wired Pos earth and the guy had bought an expensive neg earth dipping LED headlamp bulb. Ron

email (option): ronpier@talk21.com

My understanding was that the LED tail and stop lights are not polarity sensitive (at least the one I bought wasn't).

The headlamps are definitely polarity sensitive (and useless by the way) and quite difficult to get positive earth 6V versions at a reasonable price.

email (option): sacombsashtrees@hotmail.com

I've bought from this guy. Lots of products and info on his website. All the bulbs are available in either pos or neg earth.
http://www.dynamoregulatorconversions.com/

Ron

email (option): ronpier@talk21.com

Hi Ron

Did you manage to test your special with an LED headlight fitted in the dark yet.

I would be interested in your results.

Mine is useless in total darkness, lots of light, but no focus at all. I have difficulty riding it at more than 10 miles per hour, if that.

Regards

Pat

email (option): sacombsashtrees@hotmail.com

Pat I've never really ridden it in total darkness, only in lit areas, where I'm more concerned about being seen than seeing. As you say, lots of bright light but as for focus, I'd need to check that out. Where I live, I'd have to ride quite a long way out of town to find unlit roads, which is nowhere I'd need to be at night. I'm basically a daytime rider but of course I've been caught in poor light or darkness on lots of occasions.

My most memorable night ride was from a pub near Fontwell in Sussex where we arrived in daylight by duel carriageway, but the pub landlord directed us back to Goodwood via pitch black lanes. I was on my WD/CO with standard bulbs and my mate Tim's G3L tail lamp had gone out. Definitely 7 miles of the blind leading the blind that night. Ron:flushed:

email (option): ronpier@talk21.com

I live about 8 seconds (at M20 speeds) from unlit country lanes...I decided to take my M20 out for a test run with the blackout mask fitted and it was bloody scary even at slow speeds..:laughing: ...

I'm confused by these posts...if LED lights are not 'earth sensitive' why are they sold as positive or negative earth?...

If the beam is so poor with LEDs it would be better to stick with the original system...With a resilvered reflector and the pre pre focus bulb set up correctly the lights aren't too bad...(without the blackout)...Ian

email (option): ian@wright52.plus.com

Hi Ian

I have not seen bi-polar (if that is the phrase) headlights, but unless my memory isn't serving me well I did buy some bi-polar stop/tail bulbs.

Why some are polarity sensitive and some not, I have no idea.....one for Noam.

Regards

Pat

email (option): sacombsashtrees@hotmail.com

I just tested two spare LED bulbs I have. One is a nice red stop/tail with rear facing white lights for number plate illumination which only works on Neg earth. The other is a simple white pilot light bulb which works Pos or Neg.......So I don't know either? I'm sure I've got one of Henk's red tail lamp LED's somewhere, but buggered if I can find it right now. Ron

email (option): ronpier@talk21.com

LEDs that work both ways can be recognised by the ac/dc name added.

Henk

email (option): ahum@quicknet.nl

AC/DC Henk? Speak for yourself. Swinging both ways:heart_eyes: Ron

email (option): ronpier@talk21.com

Swinging both ways still in Greece. The days are generally very nice but the evenings are quite cold. Luckily I don't have to sleep in my tiny caravan.

Henk.:flag-gr:

email (option): ahum@quicknet.nl

L ight E mitting D iode = LED

Diode a one way voltage sensitive resistor.

Remember diodes only let power through in one direction which is how a recti frier works.

So an individual LED only works one way.

A first year electrical engineers prac class is to INVERT a DC circuit ie switch + & -.
so it is a simple task to add some circuitry inside the bulb to invert the power.
However this cost money, reduces reliability & adds heat 3 thinks you are trying to avoid.

Most of the high intensity LED's are the CREE style and they run at 3 V or to use jargon have a 3V driver.
Thus the double dipper which has a resistor on the low beam to cut the voltage down to 3 V and on high connects both in series bypassing the resistor.

email (option): bsansw1@tpg.com.au

I am using ac/dc LED's for my BSA's for many years now and they work just fine and they are rather cheap to get.



Henk

email (option): ahum@quicknet.nl