Voltage Regulator for a Small Motorbike, 6V AC Current

[BoTyGuy]

I hesitate to post up on something started so long ago, but since I own a couple of these bikes, let me chime in. The ignition circuit on these bikes uses a mag coil that is grounded by a NC brake light switch to chassis ground, allowing it to create magnetic charge and power. The thing that confuses most, is the wiring from that point. For whatever reason, Gilera decided it would be fine to just use the brake light filament circuit as a substitute ground for the mag coil when the brake switch is open, therefore allowing power from the mag coil to seek ground through the brake light bulb, giving you a brake light while still providing ground to the ignition magneto coil. Great, unless you blow a bulb due to vibration, water, damage, etc. There is a clause in the owners manual which states that should the engine die when the brake is applied, replace the bulb, or repair the green wire leading to the switch. Alternately, you can just temporarily ground the switch and the engine will run. All else runs off of the lighting coil circuit for head and tail. If you translate the Italian in the schematic, yes, you will find an item marked "impedance" in the headlight bucket to help buffer and protect the lighting circuit. Hope this helps somebody. Thanks for allowing me to post up.

 

[KeepItSimpleStupid]

That came up duing the design.build process. Bad brake light, your dead in the water. Alec did a really nice job. This and the aquarium thread. The aquarium thread I think went on for more than a year. And Alec, Salty still doesn't have any fish.

An incadesent bulb is a current dependent resistor, a regulator of sorts. I have a tube tester that uses one as a fuse.

 

[gary350]

I put a 3 HP fork lift motor on a mini pike about 40 years ago. I used the starter solenoid from a 1967 chevy truck and a N.O. push button switch to make it go. Push the button the mini bike would leave without me every time. There was no way to stay on and if i refuse to let go of the handle bars mini bike would flip over backwards. Then I put the 3 HP DC electric motor with 12v car battery on a go-kart frame. I was 165 lbs 40 years ago. Push the button tires will peal in gravel or grass. Take off on cement or asphalt it was not able to throw me off but it took off extremely quick. Max speed was 25 mph the way I had it geared. It went down the street as quiet as a bicycle. It was a lot of fun. I still have the 3 hp fork lift motor and the vintage 1965 mini bike now has a 5 hp briggs engine that does 42 mph. I should sell this mini bike no one rides it anymore. Some where I may have a pic with the go-kart with the fork lift motor.

Picture #2 a Yahama RD350 engne I think it had 6 speed transmission. We were crazy and fearless in those days we had this up to 120 mph on the highway.

Picture #3 Is 8 hp engine with propeller it was slow to take off but the faster it went the quicker it picked up seed. Max speed was 47 mph.

Picture #4 A 65 hp 4 cylinder mercury outboard motor engine water cooled it does 0 to 84 mph in 4 seconds. Go-kart weights 200 lbs. Wow this was fun. This inspired a about 20 friends to all build one we races then Sat. night at the local stock car race track.

Picture #5 2 pulse jet engines total thrust 40 lbs not as crazy as I use to be never had those over 40 mph. It might do 150 on this low racer stream liner bike. I can pedal this bike 32 mph.