Abstract: In a friction-fusion apparatus a solid state control circuit including a triac connected in series with an electric motor, and a control circuit connected across said triac including a resistor and a capacitor and a diac connected between the junctions thereof and the gate electrode of the triac. A voltage control circuit across the capacitor normally limits the voltage across the capacitor to an amplitude insufficient to trigger the diac and is operative in response to a manually actuated switch to increase that voltage, thereby triggering the diac and rendering the triac conductive to operate the motor for a selected time interval.