Patent ID: 7817326

Claim:
An electrochrome element driver for supplying electrical power to an electrochrome element, comprising: an amplifying circuit having an amplifying circuit control input for controlling a supply current flow to the electrochrome element, an amplifying circuit feedback input and an amplifying circuit output; a variable resistor element having a first resistor terminal, a second resistor terminal coupled to the amplifying circuit feedback input and a resistor control terminal for controlling a resistance of the variable resistor element, the resistor control terminal being coupled to the amplifying circuit output, wherein the first resistor terminal is coupleable to a power source and the second resistor terminal is coupleable to a first terminal of the electrochrome element such that a supply current path to the electrochrome element through the variable resistor element is formed; and a control loop capacitor coupled to the resistor control terminal for effecting a stable behavior of the supply current flow to the electrochrome element in the supply current path.