Glazing unit security system

A motor vehicle glazing unit security system comprising:

• a glazing unit mounted in a motor vehicle and comprising a tempered glass pane having a surface;
• a glazing pane breakage detector assembling comprising:
• first and second electrically conductive bus pads of electrically conductive material at spaced locations on the surface of the glass pane;
• first and second upstanding electrical lead attachment tabs secured in electrical contact onto the first and second bus tabs;
• an electrically resistive trace on the surface of the glass pane, formed of electrically resistive material different from the electrically conductive material of the bus pads, establishing an electrical interconnection between the bus pads having a non-short circuit resistance value;
• and
• security circuitry electrically connected to the detector assembly via the upstanding electrical lead attachment tabs, for sensing and responding to a change greater than a predetermined amount in the resistance value of the resistive trace.

A motor vehicle glazing unit security system comprising:

• a glazing unit mounted in a motor vehicle and comprising a tempered glass pane having a surface;
• a glazing pane breakage detector assembling comprising:
• first and second electrically conductive bus pads of electrically conductive material at spaced locations on the surface of the glass pane;
• and
• an electrically resistive trace on the surface of the glass pane, formed of electrically resistive material different from the electrically conductive material of the bus pads, establishing an electrical interconnection between the bus pads having a non-short circuit resistance value;
• security circuitry electrically connected to the detector assembly for sensing and responding to a change greater than a predetermined amount in the resistance value of the resistive trace;
• and
• multiple additional glazing units mounted in the motor vehicle, each having a tempered glass pane having a surface and a glazing pane breakage detector assembly comprising:
• first and second electrically conductive bus pads formed of electrically conductive material on the surface of the glazing pane, and
• an electrically resistive trace on the surface of the glazing pane, formed of electrically resistive material different from the electrically conductive material of the bus pads, establishing a non-short circuit electrical interconnection between the bus pads;
• wherein the security circuitry electrically interconnects the detector assemblies in series, for sensing and responding to a change greater than a predetermined value between 5 and 50 ohms in a cumulative resistance value of the resistive traces between 10 and 1,500 ohms, and the resistive traces have dissimilar configurations.

A motor vehicle glazing unit security system comprising:

• a backlite mounted in a motor vehicle and comprising a tempered glass pane having a surface;
• a backlite breakage detector assembly comprising:
• first and second electrically conductive bus pads of electrically conductive silver-filled paint material on the surface of the glass pane at a predetermined distance between 0.5 and 2.0 inches from each other,
• first and second upstanding electrical lead attachment tabs secured in electrical contact onto the first and second bus pads, respectively, and
• an electrically resistive trace on the surface of the glass pane, formed of electrically resistive polymeric material self-adhered to the surface of the glass pane and different from the silver-filled paint material of the bus pads, establishing an electrical interconnection between the bus pads with an electrical resistance value between 500 and 1,500 ohms;
• and
• security circuitry electrically connected to the detector assembly via an electrical lead attached to the attachment tabs for sensing and responding to a change in the resistance value greater than a predetermined amount between 5 and 50 ohms.