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Electric motors and the conservation of energy

Taylor Tompkins
class: F211x-F04
Nov. 22, 2014

Objective: This project is going the show the isolated system of the output and input of an electric motor doing work. Testing whether or not the system conserves energy when converting electric energy to mechanical rotation.

World applications: Understanding the energy transfer within this electric mechanical system will allow for the development for more efficient electric motor circuits reducing power consumption.

Procedure:

First we need to set up an experiment that will look at both the input and the mechanical output of an electric motor. For this experiment it is done with a hanging weight on a steel pulley, then a arduino uno with data-logging is set up to read and graph voltage. For the current a fluke meter was used to measure current continuously through out the testing. This can all be seen in figure 1, 2 and 3.

Figure 1: output of experiment

Output: The photo above is the output of the electric motor notice the marked spot on the pulley that is the place where to string is attached to the weight. This was put on the side θ=0 because if the sting was placed vertical when the motor was activated it would violently yank the string and ether break it or would have fluctuating data on the data-logger. With it on the side the movement was calm and linear.

 Figure 2: measurement of input

Input: Above this is one of the components used to isolate the system on the input side. This was set up to read voltage across the motor and was programed to record voltage measurements every hundredth of a second so, cent-seconds.

Figure 3: Calibration and current measurement.

Other measurements: Above is the other equipment for measuring and calibrating the arduino and circuit set up.

Please review the equation and definition section before moving to the rest of the experiment.