Parameter Values:

The specific parameters for the exercise bike generator are fairly easy to meet. It should provide enough energy to charge a battery that can be used to charge other battery powered appliances and it should give the user some amount of exercise.  It was predicted with some preliminary motor testing that if the motor were operating at 2020 RPMs it should generate 9.85 Amps and 57.13 Watts.

Success Criteria Values:

To be considered a success during this testing aspect the exercise bike generator must produce some amount of power and charge the 12V battery in the system. Therefore the battery must exhibit higher potential at the end of the test than at the beginning. Additionally the generator must be able to adapt to different exercise platforms and not break during any of the tests.

Conclusion:

The figures that were recorded during the test exhibited much higher RPMs, much lower average current but very similar average power output. The range of RPMs in which the generator operated were between 3450-3920 RPMs. The average current that was calculated from all of the data points during the 5 minute test period was 4.16 Amps. The average power production during the duration of the test was calculated to be 59.82 Watts. The test generated .355 Amp hours for the five minutes of operation. This means that it would take approximately an hour and ten minutes to charge the 5Ah batter from no charge to full charge. For ease of comparison the predicted values versus the tested average values are listed in Figure 1. 

The generator managed to produce nearly enough energy to power a decent light bulb on the electrical end. It is possible that power output could have been optimized further by enhancing the stability of the generator. During operation of the generator it made a considerable amount of noise and vibration. During several tests the vibration was sufficient to rattle the small sprocket off the shaft of the motor. This issue was addressed with an application of lock-tight. The noise and vibration may have been due to the large sprocket being out of concentricity by .053 inches. The geometry of the frame was also skewed by the bending process used to bend the square tubing which caused the tubing to twist. This caused the leg mounting plates to be out of parallel which may have also contributed to the vibration.