a crazy, but possibly useful idea.

Toby woodman

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I know I'm making up a few new ideas here but stick with me, and let me know if you have any input. On my hunt for a low-maintenance and easy form of transportation. I use my bike for my main transport, I don't like remembering to charge or faffing with quality chineesium alloy parts, and I love the smell and running of an engine. I think I want to go electric for the drivetrain, but not use batteries, they are expensive, they lose performance as they discharge, and need replacing every so often. I have a small 850-watt generator, which is easily small enough to mount in the frame. I can find a brushless motor wheel for cheap which looks to be alright in quality. Does anyone know how to link the two together, the wheel will draw about 800watts at max, but I won't be traveling that fast all the time. How can I make this work?
 
If you rectify AC Voltage you get a DC voltage of .637 times the AC. Assuming its 120 volt output, the dc will be 76.44 volts dc. That is within the range used by 72 volt ebikes.

If its 220volt only there isn't an easy way out here.

@bakaneko has done a hybrid build.
 
Is this 850 watt generator outputting AC or DC voltage? If so, is it also already regulated to a specific voltage? I assume it is a 110VAC, but you never know unless you ask.

What you want to do is feasible, but it all depends on what you are starting with.
 
850wt generator? I assume pedaling will power this. At various speeds the output will vary greatly. Hub motors rely on a constant v/amp supply to work efficiently. Have you thought of this?
 
850wt generator? I assume pedaling will power this. At various speeds the output will vary greatly. Hub motors rely on a constant v/amp supply to work efficiently. Have you thought of this?
Nah, he wants to do a fuel/electric hybrid similar to a Train locomotive from what I can tell. The fuel engine is tied to a generator and motor power is supplied by increasing load on the generator and RPM on the diesel engine. It's not overly complicated, but does require a fair bit of math. Even if a constant voltage is required the engine and generator combination can be run at different RPM to increase amp output.


The biggest issue, honestly, is going to be the output of that 850W generator. Not accounting for any losses along the way, that little generator could supply the right amperage for about a 750W motor at 48V, with a little left on the table. Not too bad, but it won't be a rocket ship either.
 
its a 230 volt with a maximum of 13 amps. I am looking into ways to invert the current to dc, and get more amps with less voltage.
 
Be interesting to watch your progress, keep us updated please. Hope it works out.
 
It would need to be a fan cooled engine running at full crack- and thats going to be loud.

The most cost effective, compact way of doing this is getting 24V alternators with V-belts and are self-exciting.

A single 24V alternator can provide 1000W at about 26V for about $90 (71GBP)
 
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