Abstract: A combustion-powered tool having a workpiece contacting element movable relative to the tool as the tool is depressed prior to firing includes a spark unit having a high voltage spark supply for providing an ignition spark, a printed circuit board having a first portion configured for receiving and being electrically connected to the high voltage spark supply, and a second portion configured for receiving and being electrically connected to both an actuator switch and a trigger switch, the switches and the spark supply being electrically connected so that to enable firing, the workpiece contact element actuates the actuator switch, which then enables activation of the trigger switch. A unitary actuator has a fixed end, a movable end engageable by movement of the workpiece contact element and a middle portion for engaging the actuator switch upon movement of the movable end caused by depression of the tool against a workpiece.