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Title: Flash protection controller

A controller provides a high voltage to maintain an electro-optic shutter in a transparent condition until a flash of light which would be harmful to personnel is sensed by a phototransistor. The controller then shorts the shutter to ground to minimize light transmission to the user and maintains light transmission at the pre-flash level for a predetermined time to allow the flash to subside. A log converter and differential trigger circuit keep the controller from being triggered by other light flashes which are not dangerous.
Authors:
 [1]
  1. (Mountain View, CA)
Publication Date:
OSTI Identifier:
863946
Report Number(s):
US 4282429
DOE Contract Number:
AT(29-1)-789
Resource Type:
Patent
Research Org:
Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA
Country of Publication:
United States
Language:
English
Subject:
flash; protection; controller; controller; provides; voltage; maintain; electro-optic; shutter; transparent; condition; flash; light; harmful; personnel; sensed; phototransistor; controller; shorts; shutter; ground; minimize; light; transmission; user; maintains; light; transmission; pre-flash; level; predetermined; time; allow; flash; subside; log; converter; differential; trigger; circuit; controller; triggered; light; flashes; dangerous; trigger circuit; light transmission; light transmission; predetermined time; ash level; controller provides; determined time /250/