Generator Q: Hand Generator to Electric Motor Efficiency

  • Thread starter Thread starter Grabowski
  • Start date Start date
  • Tags Tags
    Generator
AI Thread Summary
The discussion centers on the efficiency of transferring energy from a hand-cranked generator to an electric motor compared to a purely mechanical system. Participants note that both mechanical and electrical systems experience energy losses due to factors like friction, internal drag, and electrical inefficiencies. While motor efficiencies can range from 80% to 95%, the overall efficiency depends on the specific configurations of the systems involved. There is skepticism about the feasibility of using motors to power each other, as this concept resembles a perpetual motion device, which is fundamentally flawed. Ultimately, practical experimentation with identical motors is suggested as a way to assess efficiency directly.
Grabowski
Messages
13
Reaction score
0
If you are turning a generator by hand that is directly wired to a electrical motor will it transfer the electrical energy produced by the generator to a electric motor more or less efficiently then with a pure mechanical system? assuming that the input energy is located away from the output such as a gear system on mechanical or circuitry/wires on electrical. So would there be more energy lose through the mechanical gears/belts or circuitry.
 
Engineering news on Phys.org
This sounds like homework.

What are your thoughts?
 
Vertical axis wind turbine boat... I've seen mechanical versions no electrical
 
""" more or less efficiently ..."

what's losses in a mechanical system? I'm no mechanical so don't know.

rotating electric machinery has losses too
friction, internal drag from windage, and electrical losses in copper and iron.

this link has a table of motor efficiencies http://www.nema.org/gov/energy/efficiency/premium/
click this line
NEMA Premium Energy Efficient Product Specification and Definition
and it'll open this pdf document

javascript:HandleLink('cpe_6667_0','CPNEWWIN:child^toolbar=1,location=1,directories=0,status=1,menubar=1,scrollbars=1,resizable=1@/stds/complimentary-docs/upload/MG1premium.pdf');

as you see they run ~80% to 95% .

square that number because you have similar sized motor and generator...

then get an estimate from a mechanical type.
 
Last edited by a moderator:
If there is a complicated or large drivetrain involved, it may well be more efficient to convert to electrical and back to mechanical, but it depends on the specifics of the systems.
 
Chain drive is pretty good.
 
I don't think my question is understood... But thanks for your time everyone...
I think the only way is to get two of the same motors, hook them up and give it a go...
 
Grabowski said:
I think the only way is to get two of the same motors, hook them up and give it a go...

Please tell me you're not trying to get them to power each other...
 
Why not? any electric motor can be used as a generator can it not?
 
  • #10
And both motor and generator are not 100% efficient. Power out of one will be less than the power put in. Total loss, the system will gradually (or rapidly) grind to a halt.
 
  • #11
Grabowski said:
Why not? any electric motor can be used as a generator can it not?

Because it sounds like you're trying to make a perpetual motion device, hoping that each motor will generate power for consumption by the other.

No offense to you, Grab, you are likely not aware of the uncountable number of people that have gone down this road ahead of you. This should be a mandatory lesson in grade school science. The number of person-hours wasted on people coming up with this exact idea and trying to bring it to life could be much better spent making some more meaningful contribution to society.
 
Back
Top