Controlling dynamic systems by measuring the short circuit current of a photovoltaic generator

A window shade assembly, comprising:

• a roller shutter apron,
• a photovoltaic generator, connected to said roller shutter apron,
• a battery being supplied with electrical energy by the photovoltaic generator and supplying said roller shutter apron with electrical energy, and
• a control module based on sunlight,
• wherein said photovoltaic generator is electrically isolated from said battery,
• wherein the isolated photovoltaic generator has the short circuit current,
• wherein said control module determines said numerical value being based on at least one reading of short circuit current and corresponding to the reading of the short circuit current,
• wherein said control module compares said numerical value determined with at least one reference threshold value,
• wherein said roller shutter apron is controlled by said control module, when said numerical value corresponds to a value range limited by the at least one reference threshold value, said roller shutter apron having a configuration corresponding to said value range, and
• wherein said control module comprises:
• means for electrically isolating the photovoltaic generator from the battery;
• means for taking a reading of a short circuit current of the photovoltaic generator;
• means for determining a numerical value corresponding to at least one reading of the short circuit current;
• means for comparing said numerical value determined with at least one reference threshold value;
• means for controlling an isolating means, said means for determining the numerical value, and said means for comparing;
• and
• means for controlling roller shutter apron according to a result of comparison between said numerical value and the reference threshold value.