Power Generator Experiment

   Have  you ever wondered how  a hand crank  generator works?  I know I have wondered about it few times. Luckily  for you, I had to opportunity to learn how they work and actually test the theory of a lab experiment .

   Lets start with the basics; the principle behind a hand crank generator is  Faraday’s Law.  Faraday’s Law states that changing magnetic fluxes through coiled wires generate electricity (currents and voltage).  The greater is the change in magnetic flux, the greater are the currents and voltages. The change could be produced by changing  in the magnetic field strength, moving a magnet toward or away from the coil, moving the coil into or out  of the magnetic field, rotating the coil relative to the magnet,etc.  For this lab we shaked a tube which has a magnet that will travel back and forth through a coil of wires (see image below); and like we just learned the moving magnet through the coil will produce a change in the magnetic field which will result in  a voltage.

   Our voltage was measured and recorded with the LEGO mindstorm. The use of this program allowed us to  transfer the data that was obtained into an Excel spreadsheet.  We performed this experiment 4 times;  each time  decreasing the tube’s shaking speed. We expected that   the faster we shaked the tube(results in a greater number of shakes), the greater will be the generated voltage and vice versa.

   One  more thing that I believe is worth mentioning; is that the data acquired by the software consisted of 30 data points per run. These numbers  were squared and added all together; this process is also know as the sum of squares method. The reason we did this is because this method  provide a quantity that can used in describing how well a model, often a regression model, represents the data being modeled. The table of results that I am showing below only provides the final quantities after this modeling method was applied to each run

Table 1 : Final results after 4 trials  with power generator

These results can also be  represented graphically

Graph 1 : Graphical representation of  Sum squares of the voltage vs number of shakes

   From the results from above we can happily conclude that our results matched the expected outcome. The faster  the tube was shaken the higher was the voltage obtained.

I hope you enjoyed this post .