>> Under $US25 in modest quantities fully built FOB Taiwan 
>> :-)


> Maybe this is asking too much.........
> 1) What kind of permanent magnet alternator do you get 
> from Taiwan
> for $25 ? output ? and at what kind of quantities ?  1000 
> pc 10K pc ??

Spec pretty much as I said initially - see below for more 
comment:
About 300 Watts at 1800 RPM. Maybe 1500 RPM. Maybe more 
Watts.
That price is probably in the 100's to 1000's volume.
Bearing in mind that the labour content costs very little.

> 2) The 1KW alternator your friend is developing ?   Will 
> it be made
> available ? What is the voltage output curve and power vs 
> RPM ?

He would probably make it available if there was adequate 
interest. It's hard to beat Chinese purpose built equipment 
for price and his is built for a niche non alternate energy 
application. But I suspect that it would sell quite well for 
windmill and similar use.

_____

> This alternator
>
>        http://others.servebeer.com/misc/alternator.jpg
>
> has NO discernible cogging. It, and others like it, will
> turn with the slightest of input.

> ... magnetic field
> pattern is not aligned with the physical magnets.

> This alternator is capable of about 300 Watts at 1800 RPM
> but the person who designed this is about to produce a 1 
> kW
> or better unit at the same or lower RPM.

Output initially increases approx as speed^2 until iron 
saturates (at which point torque becomes ~ constant) so then 
power  increases about linearly with speed. The changeover 
point depends on magnetisation and airgap but is probably 
around 600 RPM.

So, driven from a drag rotor machine (Savonius and friends) 
this requires a bit more speed than they are happy with for 
best performance but for a lift rotor machine (VAWT Darrieus 
and HAT prop based) with quite modest Tip:wind speed ratios 
it would be a good match.

I keep not getting to trying one "lying on its back" with 3 
airfoils intended for this

    http://tinyurl.com/5cmb42

but instead standing vertically on 3 radius arms and making 
a hopefully fine imitation of a Darrieus. Maybe with a small 
Savonius on top to make it self start.




        Russell





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