to voltage setting to use it is safer to set slightly on the low side. This is based on the fact
that as your panel heats up the maximum power point voltage will drop. Also the slope of
the panel power curve is not as steep on this side of the power peak, meaning any errors
in setting results in a smaller power loss.
Be careful to set operating voltage correctly (ie. slightly below the maximum power
point of your panel)
Mr Stan Woithe has tested the electronics systems available and concluded there is very
little difference between them. I expect his report will be posted on the South Australian
web site by now.
SETTING YOUR ELECTRONICS:
It is possible to select a compromise voltage setting that will keep your panel power
within about 3% of maximum over light level variations from 20% to 100% provided
you maintain the same panel temperature at the start of each race.
This means effectively (provided you are prepared to accept a small power drop) you can
preset your electronics and not need to re adjust it over the course of a days racing.
See Appendix N for details.
Since November 2010 the Automax electronics unit has been commercially available It
automatically sets to the maximum power voltage and tracks that voltage as it changes.
This totally removes the need to ever adjust the electronics.
HOW DO THE ELECTRONICS SYSTEMS FUNCTION:
The following description of the electronics systems typically in use is only a simplistic
overview. The various manufacturers have detailed descriptions of their particular units,
refer to these for full details.
This description only covers the units I have measured. There are others out there that I
have not either seen or tested. Listed below are the units I have tested
Engelec Max 4
Scorpio
Easymax III
Automax (became available late 2010)
Box Hill High School versions 1,2,3 and 4.
The best general description for the units that I can give is Input Controlled DC to DC
down Converter.
What does this really mean?
It means that the input voltage is controlled, that is held constant at the value you have
set which should be just below the maximum power voltage of your panel. An electronics
unit that automatically tracks the solar panel`s maximum power voltage was put on the
market in November 2010.
By holding the solar panel at its maximum power voltage all the power available from the
solar panel is being fed to the motor at all times irrespective of sun level motor speed or
load. Whereas without an electronics unit the power fed to the motor is often below the