Thread: Motor Generators View Single Post

 bistander Gold Member Join Date: Apr 2015 Posts: 1,669
The guy in the video is an idiot

Quote:
 Originally Posted by BroMikey Standard equations for calculating OVER UNITY that any Engineer is using. Motor generator efficiency can be determined through the measurements of mass rotation this weight.
Even a freshman engineering student realizes the need to use the pertinent and appropriate equations. It is meaningless to just pull out any old equations from a textbook and punch numbers into a calculator as this fellow in your video has done. A minimum level of understanding physics is needed.

He knows the mass of his rotor. The equation to find force from Mass. F = M * a. Acceleration? Just use the gravitational 9.81 m/s^2. (Which actually just yields the rotor weight). Now he has a force. He multiplies times the radius of the rotor. Bingo. He has a torque number, so he thinks. Find the next equation, power = torque * rotational velocity. Plug in a conversion of RPM to radians/second and he has 1799 watts. That's 2.4 hp. He uses that as output power from his motor to calculate efficiency. Nevermind that nothing is connected to the motor shaft, so motor output power is necessarily zero. Therefore efficiency is zero.

But apparently all it takes to convince you of OU is a video of something rotating and some flashing LEDs.

bi
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