Patent ID: 7446292

Claim:
An auto darkening eye protection device comprising: a shutter assembly adjustable between a light state and a dark state; and a control circuit comprising: a power supply having a voltage; a sensing circuit sensing an occurrence of a welding arc and providing an output indicative of the occurrence of the welding arc; a weld detect circuit receiving the output of the sensing circuit, the weld detect circuit enabling a dark state drive signal to be delivered to the shutter assembly; and a positive voltage generator and a negative voltage generator receiving power from the power supply and cooperating to output the dark state drive signal directly to the shutter assembly to switch the shutter assembly from the light state to the dark state upon enablement by the weld detect circuit, the dark state drive signal including a high voltage pulse followed by a stable AC waveform, the high voltage pulse being formed by a positive voltage signal and a negative voltage signal, the positive voltage signal having a magnitude greater than the voltage of the power supply.