Over the weekend, I made progress! My husband helped me install a digital speedometer and determine the target speeds for specific voltages. Then I pedaled for 2 hours and charged a hand-me-down iPhone (see video below).
Here are some pictures of the speedometer installation process. The gap between the sensor and the magnet was too large at first, so I cut a piece of cork to fill in some of the excess space.
Here are some pictures of the speedometer installation process. The gap between the sensor and the magnet was too large at first, so I cut a piece of cork to fill in some of the excess space.
Here are the speeds and approximate corresponding voltages (without the voltage regulator attached):
8 mph - 32 volts
10 mph - 40 volts
11 mph = 45 volts
12 mph = 48 volts
13 mph - 51 volts
15 mph - 58 volts
16 mph - 62 volts
17 mph - 65 volts
8 mph - 32 volts
10 mph - 40 volts
11 mph = 45 volts
12 mph = 48 volts
13 mph - 51 volts
15 mph - 58 volts
16 mph - 62 volts
17 mph - 65 volts
To produce 15-20 volts, one must pedal at 4-5 mph. The voltage regulator will step the voltage down to a steady 14 volts. However, I noticed as I pedaled that the green light on the inverter did not illuminate until about 4.6 mph. To charge the cell phone I tried to pedal at a steady 5 mph. Occasionally the inverter went into thermal shutdown. When this happened, the load decreased and the resistance to pedaling dropped noticeably.