- Solar Panel voltage, current and ability to easily reconfigure them,
compatibility with motor - Motor characteristics required. Voltage, RPM range, efficiency, power and
compatibility with solar panel - Correct gear ratio to match loads, and the ability to quickly change ratios as
sun levels change
A few words on gear ratios:
Sometimes it may not be possible to obtain the exact gear ratio required by changing
gears alone. There is always the option of arranging your solar panel wiring so it can be
reconfigured in series and parallel to change the output current and voltage. This will
change motor torque and RPM. This change can be accomplished quickly by the flick of
a switch.
Do not forget changing wheel diameter, this is commonly used as an alternative method
to changing gears, it achieves the same result as changing gear ratios. Remember to
readjust the guides to suit the new ride height.
DYNAMOMETER TEST RESULTS:
Below are graphs of dynamometer test results. NOTE: All Sun levels referred to are
based on full Sun in December here in Melbourne NOT AM 1.5 which will be the 100%
Sun level used in future ie. Feb 2010 onwards.
The tests were conducted with a Faulhaber 2232 6 volt motor powered by a Solarex SX
10 panel configured either with all cells in series, 2 lots of 2 strings of cells in series then
paralleled and 4 strings of cells in series paralleled. These configurations giving exactly
the same power but at different voltage and current levels.