III. Our Comparative Tests: Tesla Baseline, Variable Winglet Geometry 

April 29, 2002

In this section we are going to review how our empirical (experimental) tests were set up, and how any of our club members might duplicate the tests on low budgets.

In our first set of photos you can see our complete set up which includes the assembled turbine, a Hall-effect rpm sensor, a pulse conditioner, and a frequency counter. The Hall-effect sensor (Radio Shack source) reacts to a magnetic field. In our case we attached a permanent magnet to an aluminum cam plate on the end of the turbine shaft. The signal from the sensor was conditioned by 74LS132 Schmitt trigger to remove noise -- before entering the frequency counter. Our garden-variety frequency counter accurately counted pulses in Hertz (pulses/second) -- which we later converted to rpm.

 Our next photos show components sets back from our laser cutter, and how we assembled them into disk packs for our initial tests. In order to create a baseline to work from, two disk packs were assembled with identical spacing (0.125 inch) -- one modeled after Tesla's improved design, the other adhering to our improved design theory. The Tesla design was used as the baseline to compare our modifiable disk pack to. Simply put -- if spin-up runs improved over the Tesla disk pack, we were moving in the right direction. 

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