Inferential temperature measurement of an electrochromic device

A process for driving an electrochromic (EC) device comprising:

• applying a driving signal to bleach or color the EC device, wherein initially the driving signal has a voltage amplitude that is harmless to the EC device at any temperature;
• measuring a first voltage amplitude of the driving signal applied to the EC device;
• measuring a second voltage amplitude of the driving signal applied to the EC device;
• measuring a first current amplitude of the driving signal applied to the EC device;
• measuring a second current amplitude of the driving signal applied to the EC device;
• determining a voltage amplitude difference between the first voltage amplitude and the second voltage amplitude;
• determining a current amplitude difference between the first current amplitude and the second current amplitude;
• determining a first resistance from the voltage amplitude difference and the current amplitude difference;
• determining a second resistance by subtracting a third resistance from the first resistance, wherein the third resistance is a static resistance of the EC device that is static relative to temperature change of the EC device;
• and
• adjusting the first and second voltage amplitudes to a maximum amplitude that is harmless to the EC device at a present temperature that is inferred from the second resistance.