Build A 12volt Generator

A

AssembleThis

New Member
Building a 12volt generator should not be that hard. If you have a burnt out magneto then you have what you need to start building your own. The object is to have more AC than the say 13 or 14 volt DC supply you need. So I'm going to keep winding coils until I make one with the sweet spot of 18 to 20volts AC. As you see in the picture the magneto on the left is the new generation type with no white wire or 6volt coil. The center one is the old type showing the 6volt coil. The one on the right is a stripped magneto that's ready to be modified. Since no two engines are alike you need to measure the distance from the right side of the magneto on your engine to the right side wall. This will tell you how much clearance you have to work with. The first cut you make is that one but you don't cut through all the plates. The very top plate do not cut, that's the bracket that will hold the generator in place. I'm going to be using 28 gauge magnet or coil wire for my first coil. If I find that's too thick to get the needed voltage then I'll go to 30 gauge. I've decide to use fiberglass as my coil form, since I also do auto body work I have tons of it laying around. You want 1 layer of material on the plates before winding. Do not allow the coil to touch the plates. On the left or right as well. Gasket material is also an option. I'll be winding my coil like an hour glass since I'm using a pull starter on my engine. Clearances are very important.
Leave about 3" of wire hanging when you start your coil, this will have a brass or copper lug soldered to it as the ground. You don't want anything touching that coil I cant stress that enough, so check then check again before you start winding. I will post on this again after I've wound my first coil and tested it.
http://i.imgur.com/QlXf8fV.jpg
So stayed tuned to the AssembleThis channel!
zpt
 
We'll be interested to see what you come up with. Charging batteries from the engine is always something a lot of us would find attractive.

I run 12 volts systems on my bikes using an SLA battery. Charging it is simple and easy with a battery charger in my garage but to keep it charged from the engine would make it better. So far I haven't found anything that works well.

Good luck.

Tom
 
2door said:
We'll be interested to see what you come up with. Charging batteries from the engine is always something a lot of us would find attractive.

I run 12 volts systems on my bikes using an SLA battery. Charging it is simple and easy with a battery charger in my garage but to keep it charged from the engine would make it better. So far I haven't found anything that works well.

Good luck.

Tom
Click to expand...

How many amp hours are you using for the 12VDC? I'm looking to run LED stop light, turn signals, flasher and headlights on mine.

Do you store the battery in a battery box? Where do you install it on the bike?
 
Hmmmm Has there been any progress with your winding? Like what gauge wire and how many turns - or footage. how many volts at what amperage? Or are you still in the testing stage?
 
yes boxcar I have seen those. But will it work on the HS142 4 stroke? looks like it is for a 2 stroker, and would be hard to find a place to mount on the 4 stroke. different flywheel.
 
Good point. I guess I missed the 4 stroke part..... Silly me...
I think if I were trying to run a Generator / alternator on a 4 stroke, I'd belt drive a Mini 35 - 40 amp Bosch or Denzo .... I know it's overkill but they are very small , available and pretty cheap.
I'v run them on many custom applications.
 
It's more than likely just a rectifier . It'l convert the AC output from the mag to dc.
Kind of an expensive set up.....
 
boxcar said:
It's more than likely just a rectifier . It'l convert the AC output from the mag to dc.
Kind of an expensive set up.....
Click to expand...

I just want a coil on core to get the 12 volts i need. For a 4 stroke HS142-f
The part I am assuming is the part that has all the copper windings creating a current when the magnets swing past it making at least 12 volts at maybe 1 to 2 amps. that should be plenty for front and rear LED's . well if it supplied around 7 or 8 watts would be good.

abiker made one a few years ago, but never knew if he has finished making them or where to get one of his?

The full wave rectifier part I can make with four diodes, and regulate it all with a couple resistors and a zener diode.
 
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