Ok lets assume there is small DC motor being used as generator, it out puts ~90V when being spun at 9000 rpm. It can handle a 3-5A load. Now lets assume you need to drive something that is 24V and around 10A, or better still more than one 'thing' from this source.

What is the best way to approach it?

A couple of things to keep in mind..... The 'thing' being driven isnt a constant load, but the max load is 10A. This is mainly a build rather than a buy situation. So how would you tackle it?

 

Standard SMPS. Most units with the universal 85 - 250 VAC input rating will run just fine on 90 volts DC input at or near their rated capacity.

I've played with many that ran fine down to around 40 VDC inputs before they lost output voltage regulation at partial loads.

 

Ok next question.

Now we have the output.......... How would you go about distributing this to 4 other 'things' that need the same? Still using 1 90V DC motor as the source. Best I could come up with was a Capacitor bank and kind of PWM the supply to each 'thing' in quick turn.

Weight might also be an issue, the motor (90V), weighs in at 350g. The goal is under 1KG for everything.

 

Or taking the 90V and stepping up, storing in a cap bank then stepping down to each 'thing'.