Variable-speed trigger switch having a conductive elastomer

An apparatus comprising:

• a motor;
• a trigger assembly including a trigger member and an elastomer member mechanically coupled to the trigger member and moveable along a movement axis, wherein the elastomer member includes an electrically-conductive non-planar surface;
• a controller configured to operate the motor;
• and
• a circuit board oriented substantially perpendicularly to the movement axis, the circuit board including a plurality of conductive tracks facing the non-planar surface of the elastomer member and coupled to a resistor divider having a divider output, wherein the plurality of conductive tracks include a plurality of ring-shaped or arcuate tracks arranged substantially coaxially with the movement axis of the elastomer member such that, as the elastomer member moved in the direction of the circuit board, a variable number of the plurality of conductive tracks is progressively engaged by the non-planar surface of the elastomer member, providing a current path from the elastomer member to the divider output of the resistor divider through a corresponding variable number of resistors in the resistor divider,
• wherein controller is configured to vary a speed of the motor based on the output of the resistor divider.