Patent attributes
The force sensing dome switch is configured to simultaneously, or nearly simultaneously, close or open two separate circuits. For one of these circuits, the force sensing dome switch acts as a variable resistor whose value is controlled by applied force. Each force sensing dome switch is disposed upon a printed circuit board (PCB) comprising two separate circuits. An example force sensing dome switch comprises: a conductive dome in conductive contact with a first trace of a first circuit, the conductive dome is configured to make conductive contact with a second trace of the first circuit when pressed down; and a force-sensing resistor element positioned between the PCB and the conductive dome, the force-sensing resistor element overlays a pair of interdigitated traces of a second circuit and is configured to conductively connect the pair of interdigitated traces when pressed against the PCB by the conductive dome. The force-sensing resistor element is a layer of material whose resistance changes when force is applied.