Radiant energy – Photocells; circuits and apparatus – Photocell controls its own optical systems
Patent
1991-03-25
1993-10-12
Nelms, David C.
Radiant energy
Photocells; circuits and apparatus
Photocell controls its own optical systems
250214B, 250214RC, G01J 132
Patent
active
052528170
ABSTRACT:
A power supply circuit for a liquid crystal welding lens or shutter develops a relatively low voltage AC signal for driving or powering the liquid crystal shutter to the clear state and two relatively higher or larger magnitude AC electrical signals for initially driving the shutter to the dark state and then for maintaining the shutter in the dark state; a variable frequency circuit for varying the frequency of the driving signal to the shutter to minimize power usage in the dark state and to avoid flicker in the clear state; and power saving and battery level indicator features are included.
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Fergason Jeffrey K.
Fergason John D.
Le Que T.
Nelms David C.
OSD Envizion Company
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