Electrochromic system with measurement of charge to be transferred
AssigneeSaint-Gobain Vitrage International
InventorsXavier Ripoche, Marc Ast
Life of this patent
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Abstract
An electrochromic system for controlling the color state of an electrochromic pane. The charge needed to obtain the desired color is determined from the discharge potential of the system and the coloration set-point. An integrator measures the charge passing through the system and compares it to the charge to be transferred. This charge is measured by a differential amplifier which compares a discharge potential measured by a capacitor with a selected color set-point.
Claims13
A method of controlling the color in an electrochromic system, comprising the steps of:
- determining the charge to be transferred as a function of the discharge potential of the system;
- measuring the charge passing through the systems;
- comparing the measured charge with the charge to be transferred;
- and
- controlling the supply of current to said electrochromic system in response to said comparing.
An apparatus for controlling the color of an electrochromic system, comprising:
- a generator selectively supplying one of two coloration voltages to said electrochromic system;
- an integrator for measuring a charge passing through said electrochromic system;
- a capacitor for measuring the discharge potential of said system;
- a differential amplifier for calculating the charge to be transferred from the measured discharge potential and a selected set-point;
- and
- a comparator for comparing the measured charge with the charge to be transferred and controlling the supplied voltage in response thereto.
Dependencies are inferred from the claim text.