Hi I have a 100cc china bike that has two wires, they obviously are from the stator for a lighting option and I have powered a headlight. The light got brighter as revs increased and then at a point the bulb melted from the excessive power. I am not 100% sure on the device I need to install to regulate the power coming out to stay at 12 volts, please help, I want to power a headlight. Thanks.