Patent ID: 6535126
Filing Date: 2003-03-18
Classification: B60R,G08B

Abstract:
An electrochromic security window assembly comprising:first and second spaced transparent substrates defining a chamber therebetween, the first and the second substrates including first and second conductive coatings on respective facing surfaces thereof; an electrochromic medium contained in the chamber comprising at least one anodic electrochromic compound and at least one cathodic electrochromic compound and having reduced light transmittance upon application of electrical activation between the first and second conductive coatings above a reduction potential capable of simultaneously oxidizing the anodic electrochromic compound and reducing the cathodic compound; means for applying an electrical potential across the electrochromic medium comprising a voltage source connected in series with the first conductive coating, the second conductive coating and the electrochromic medium; and means for detecting a change in an electrical characteristic of at least one of the first and second conductive coatings and for generating an output signal in response to a change in the electrical characteristic corresponding to a break in the at least one conductive coating comprising a first sensing element connected in series with the first conductive coating and the voltage source, and circuitry for detecting an electrical condition of the first sensing element corresponding to a flow of current through the first conductive coating, for producing the output signal as a function of the detected electrical condition of the first sensing element, for comparing the output signal to a predetermined electrical condition, and for activating an alarm when the output signal is greater than or less than the predetermined electrical condition.