mtnbud

I recently upgraded my wheelset on my converted mountainbike with a Craigslist find. The front hub came with a Sram i-light D7. I bought a BioLogic Reecharge dynomo kit and want to make sure I wire it to the dynamo plug correctly. The wires from the Biologic Reecharge kit have the red and black wire, but the dynamo plug doesn't indicate a positive and minus side. Instead, the plug has a symbol that looks sort-of like a pitch fork on one of the sides. I need to know what the pitch fork symbol represents. Or in other words, does the red or black wire go on the pitch fork symbol side?

Thanks in advance,

Jeff

znomit

Pitch fork is the ground = black.

mtnbud

Perfect, thanks! Question answered!

noglider 

My approach is to try it one way, and if it doesn't work, try the other way. I have a 50% chance of getting it right the first time and a 100% chance of getting it within two tries.

zacster

That's actually not a good idea. Many electronics are sensitive to polarity and you could fry a device by applying it backwards.

A10K

Except for bike dynamos (actually generators) which are A/C devices and have no polarity. The polarity issue is dealt with inside the device attached.

znomit

Usually it doesn't matter but you can have problems with tail lights that use the frame as a ground.

zacster

I was speaking in general, but one area of bike lighting where polarity is important is in charging Li-ion batteries. Don't do that with reverse polarity.

noglider 

@zacster, you're right.