The electrochromic (EC) mirror utilizes a proprietary electrochromic chemical placed between two conductive layers and glass panels. When a voltage is applied to these conductive elements, the current flow through the chemical causes it to change in color and darken. Electrically, the electrochromic mirror behaves like a very large capacitor, typically greater than 1 F, as well as a small shunt resistance. The total capacitance measured largely depends on the total area of the mirror.

Figure 2-10 shows the EC mirror driver schematic.

Figure 2-10 Electrochromic Mirror Driver Circuit