pm generator off a scooter?

[john j]

Very often I read about homebuilders in need of a low rpm generator. When I had this small scooter, I noticed that, when trying to jumpstart it, the lamps would start glowing at zero mph. I understand this is low voltage power. But as I want to use my power for heating, (through the bulbs) this is hardly a problem.

Do I get this wrong? If I want to charge a battery, I guess I will need a voltage regulator? Any ideas (make, model etc)

John, you may need to post a clarification comment here. I cannot quite understand your question. I reread it several times and cannot quite tell what you actually are asking? Heat from bulbs apparently is involved. No prime mover is cited. Are you going to drive it with hydro, Wind, falling planes? We don't know.

[dnix71]

Sounds like a moped with a magneto. I had one in college maaaany years ago. Riding mowers with a battery start have the same arrangement. Not very efficient, but it runs the lights and keeps the battery topped off.

[Jeff]

Hmm, don't understand exactly what this is about either.

But, the subject line is exactly what I'm thinking of doing. I have a 24v electric scooter. I've found the motor (when the brushes were good), would put out 13-14 volts when driven at a reasonable RPM. Since the brushes are shot, I was thinking of making a PM generator out of it. Since the coils are already wound, why not eliminate the brushes, and tie the wiring up to whatever output I need? In other words, make the central shaft stationary, and rotate the outer casing?

[john j]

Ok, I´ll try to post more clearly. I´m building a vawt. And, looking for a generator, the idea of taking one from a scooter came up. I had several of these things, maybe 20 years ago. Still being sold today. Now chinese. The generator on these is really simple. A flywheel with pm. A coil for high tension to sparkplug. A coil for low tension for lights.

From low tension coil power goes dirctly to handlebar switch, and to the headlamp.

If engine is moving slowly, lamps are not really bright. If you go downhill it´s bright. If you dont want lights you just turn it off. Stone simple.

So the questions are: Why not use this system. Without voltage regulator if you want to produce heat with your bulbs. With some sort of voltage regulator if you want to charge a battery.

The system will probably need some sort of gearing up. I plan om using a narrow v-belt.

I know that a v-belt is not efficient. And I want to build a better alternator later.

But it would be nice to see all this spinning giving a little power. Also to keep spirits up.

[Norm]

If you want to see wind spinning a generator

just hook a 2 blade PVC 3ft. diameter to the

crank of a handcrank LED light plenty of light

....as long as the gears hold ....you won't want

too much wind....probably even need a good

furling system later

 on....about 5 minutes of

150 rpm will keep the light lit for about

 half-hour

[electrondady1]

hello john,

it's good you posted this in your own thread.

you must build an alternator to suit your mill or a mill to suit your alternator .

it will make a big difference on start up if your building a mill that is a drag type

or a lift type.

i am sure what your are suggesting will work

but,

the power of your vawt is directly related to the swept area .

it will give you x amount of torque at x rpm

you can go direct drive using lots of mags/coils

or use a pulley to overdrive a smaller alt. with fewer mags and coils.

the coils in that bike magneto will be wrapped around an iron laminate core.

when at rest they may be in a position were the the mill must over come the attraction of the magnets to that iron core in order to begin turning.

in addition , what ever ratio you decide on for an over drive must be overcome by the

start up torque of the mill .

now add the fact that your alternator will be under an electrical load even at start up and you will see that it may take a very large mill to begin turning .

lets assume that your mill does have enough start up tourgue to over come all this.

as the wind puts more energy into your mill the you must add more electrical load

in order to keep the mill speed down.

or you must  build it strong enough to run free with only a small electrical load.

[john j]

Thanks for taking your time guys. I dont have the brains to figure these things out. My strong side is finding some bits, and trying it out. I´ve tried to figure the output of my vawt. Came to 30-50watt at 10 mph wind. This generator from a scooter will take 8000 rpm or more. And my vawt is doing 30-90 rpm running without load. I will try and put it together. I´ll keep you posted. Check my pics if you like.

[electrondady1]

one thing you could try is a dc fan motor as used in a car heater.

[melder215]

i tried the 24 volt dc electric scooter motor.  heavy electric braking.  but very little voltage at the low rpm i get out of a 2 blade 8inch pvc design.  less than 1.2 volts dc.  allways twice that ac.  tried voltage doubliers with no result.  

my main windmill is a 130vdc treadmill motor, and i only get 6vdc/12vac with average winds.  am i stuck trying to gear this up, no direct drive for me? 3 blade 30+- inch long 8 inch diameter pvc blades.  slow wind.  

 

[ghurd]

The blades are too long.  Maybe try 42" dia.

G-