Disclosed herein is a system for controlling “on”/“off” functionality of an auxiliary device including a circuit designed to monitor physical rotations. The device will activate or deactivate when predetermined rotations are sensed by the circuit within a specific time period. The circuit can be used on high vibration tooling such as grinders and saws due to its resistance to relatively large vibrational noise. The circuit also includes a current sensing device to determine when the auxiliary device draws too much current. When an over current situation is measured, the circuit will automatically shut down to protect the device's electronic components. This control system can be implemented in new device designs, or installed as a retrofit control mechanism to existing commercially available devices.