- #1

cavalierean

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Hi I am trying to calculate the efficiency of my DC motor. I know that efficiency is:

Power Out / Power In * 100

I have been told by my teacher that Power In is calculated by the following formula,

Power In = Power * Time

And Power Out is;

Power Out = Mass * Gravity * Height.

I think that there is an error here in what he has given us. First of all I believe that we need to calculate work in and work out for efficiency. To do so we would need torque and RPM calculations for Work Out? And I'm not sure about Work In. Also I believe these equations he has given us have contradictory units and hence are incorrect.

Could anyone tell me how I would calculate efficiency and what equations would I need for In and Out values. And if it was torque and RPM what equation would I use, using these two to calculate the Out value.

Thanks,

Power Out / Power In * 100

I have been told by my teacher that Power In is calculated by the following formula,

Power In = Power * Time

And Power Out is;

Power Out = Mass * Gravity * Height.

I think that there is an error here in what he has given us. First of all I believe that we need to calculate work in and work out for efficiency. To do so we would need torque and RPM calculations for Work Out? And I'm not sure about Work In. Also I believe these equations he has given us have contradictory units and hence are incorrect.

Could anyone tell me how I would calculate efficiency and what equations would I need for In and Out values. And if it was torque and RPM what equation would I use, using these two to calculate the Out value.

Thanks,

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