Whats the most effiecient motor to use as generator?

[bigmark1972]

I have been working on a project recently where I want to turn a stepper motor via an air turbine to generate power. It works pretty well I have 160vdc @ .14 amps on one of my steppers and this is more than enough power for the circuit it needs to run. My question is this, is the stepper the best (most efficient) way to generate power or would some of you use another method perhaps brushless DC or induction motor?

My power needs are somewhat small 20-30 watts but I would like to generate it in the most efficient way possible any RPM is possible but I would like to stay below 2k if possible just for bearing life, balance issues etc.

Input appreciated.

 

[OperaHouse]

4400 RPM!!!!! Not exacty a little windmill in the back yard.

 

[itsmoked]

UKpete: Glad to have helped.

Opera you took a turn off the road back there... bigmark has always been talking air turbine-proportional valve controlling the air. I would not take this to mean a windmill.!

 

[bigmark1972]

3.8:1 Planetary Gearbox

[purple]You guys are on to me, this lil bugger would bring the rpm's down nicely.[/purple]

Elegant overkill! 32mm long (1-1/4" excluding shaft), 29.5mm diameter (1-3/16") outer body CNC machined from barstock, glass-filled nylon gear ring with 3 carbon-steel gears, 4mm output shaft supported by two ballbearings, mounting screws

No, it's not for a windmill, it is to be used in an industrial product I am developing and hope to market.

 

[bigmark1972]

I may or may not use a GB I have to do some calculations on torque and cfm required before I decide that.

It's on it's way I'll keep this thread updated.

 

[itsmoked]

Gearbox.. eeeeeuu. Just my opinion.

 

[bigmark1972]

I agree the motors on its way not the GB.