Mr.Dangerous

Hello, I have made a 12v battery pack and it has a positive and negative wire coming out of it. And I want to use it to light up my bicycle chopper's headlight. But the headlight is H4 and has 3 wires; High beam, Low beam and ground. I don't know which I should connect to negative and positive and worst of all, which wire should I exclude or how I can use it. Do I need some sort of converter maybe?

Thanks!

Moe Zhoost

You need a SPDT switch.

Mr.Dangerous

What's that? and what is it for? I can't figure it out

Tourist in MSN

There are three possibilities for how you wire it. Try all three and decide which light beam you like.

A - if you wire the high beam connection and low beam connection, the electricity goes through both filaments, but there is more resistance, less electricity flows through, that is the wrong combination of wires.

B - wire the ground and low beam connection, that is desirable on a car and probably best on a bicycle, the low beam filament has a small reflector over it so the light comes out of the lamp with a low beam pattern.

C - third option, the high beam connection and ground, you have more light scatter in all directions and this filament uses a bit more power than the low beam filament.

Use the option that you like best.

I assume you already know that you should not touch the bulb glass. The bulb gets very hot and if you had handled the glass enough to get any skin oils on it, the glass can break from the heat.

Moe Zhoost

Single Pole Double Throw. It's a switch that allows you to route current to either High or Low beam circuit depending on switch position. Or you could just wire it up simply without the switch as described by Mr. Tourist above. It all depends on how you will want to use the light.

VegasTriker

This may help.