Lightweight window with heating circuit and anti-static circuit and a method for its preparation

A composite transparency comprising an outer layer of rigid transparent plastic selected from the class consisting of polycarbonate and acrylic plastic having a first circuit element comprising relatively widely spaced wire runs embedded adjacent one major surface thereof, an inner layer of hard transparent plastic selected from the class consisting of polycarbonate and acrylic plastic fused to the other opposite major surface of said outer layer and a second circuit element comprising relatively closely spaced wire runs embedded adjacent the fused surfaces of said layers in spaced relation to said first circuit element in the direction of the thickness of said transparency, terminal means connected to said first circuit and adapted for connection to a ground to enable said first circuit to operate as an anti-static circuit when so connected, additional terminal means connected to said second circuit and adapted for connection to a voltage source to enable said second circuit to operate as a heating circuit when so connected.