Photovoltaic powering and control system for electrochromic windows

A device for modulating the transmission of light from a light source, comprising:

• an electrochromic element having light transmissivity that is variable in response to an electrical current;
• and
• at least one photovoltaic cell electrically connected to said electrochromic element for providing said electrical current to said electrochromic element in response to light from said light source incident on said cell;
• said photovoltaic cell being manually mounted with respect to a side of said electrochromic element opposite said light source, whereby the amount of light transmitted through said electrochromic element comprising a portion of said light incident on said photovoltaic cell is variable.

A device for modulating the transmission of light, comprising:

• an electrochromic element for varying transmission of light, said element having a first lead and a second lead;
• at least one photovoltaic cell for providing electrical current in response to incident light from said light source, said at least one photovoltaic cell having a first lead connected to said first lead of said electrochromic element, and a second lead connected to said second lead of said electrochromic element;
• and
• a shunt resistor connected to said first and second leads of said electrochromic element whereby a portion of said current from said photovoltaic cell flows through said shunt resistor without flowing through said electrochromic element.

A device for modulating the transmission of light, comprising:

• an insulated glass unit having a sealed interior;
• at least one photovoltaic cell mounted in said interior of said insulated glass unit for providing electrical current in response to incident light;
• a modulating circuit in said interior of said insulated glass unit connected to said at least one photovoltaic cell for modulating an output of said photovoltaic cell;
• an electrochromic element mounted in said interior of said insulated glass unit and connected to said modulating circuit, for varying the transmission of light through said insulated glass unit in response to an output from said modulating circuit;
• and
• a remote control system for remotely varying the output of said modulating circuit, said remote control system comprising a user input unit outside said insulated glass unit and electrically unconnected to said modulating circuit, for user control of said electrochromic element.