I am currently undertaking a project where we will be using a PMDC motor as a generator to supply a power of less than 20W to power LED's within a rotating sculpture.
I have found that the type of motor I should be looking for should have a low RPM rating at a high DC voltage e.g. 300RPM @ 30V.
I really seem to be struggling to find any motors of this rating. The closest I got was a motor with 3500rpm @ 24Vdc which cost $30 NZ and then a motor that was rated 3040rpm @ 48V but it is $267. I am pretty sure I could create a gearing ratio of 2:1 and I only require 12V. So with the 3040rpm @ 48V motor that would be 380 rpm @ 12V which sounds OK.
So I am wondering is it possible to use a geared motor as these are cheaper?
I have seen some geared motors with the following ratings:
max speed = 190rpm, Max Torque = 100nMn, Supply Voltage = 24Vdc and $124.00 with a 20:1 gear ratio. (May Be a little to low RPM?)
No Load Speed = 530rpm, Stall Torque = 110nMn, Supply Voltage = 24Vdc and $149 with a 20:1 gear ratio.
Any help would be greatly appreciated, Regards Brent Wilson mystiquesbs@gmail.com
