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Title: Flash protection controller

Abstract

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.

Inventors:
 [1]
  1. (Mountain View, CA)
Issue Date:
Research Org.:
Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA
OSTI Identifier:
863946
Patent Number(s):
4282429
Assignee:
United States of America as represented by United States (Washington, DC) SNL
DOE Contract Number:  
AT(29-1)-789
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
flash; protection; controller; provides; voltage; maintain; electro-optic; shutter; transparent; condition; light; harmful; personnel; sensed; phototransistor; shorts; ground; minimize; transmission; user; maintains; pre-flash; level; predetermined; time; allow; subside; log; converter; differential; trigger; circuit; triggered; flashes; dangerous; trigger circuit; light transmission; predetermined time; ash level; controller provides; determined time; /250/

Citation Formats

Galbraith, Lee K. Flash protection controller. United States: N. p., 1981. Web.
Galbraith, Lee K. Flash protection controller. United States.
Galbraith, Lee K. Thu . "Flash protection controller". United States. https://www.osti.gov/servlets/purl/863946.
@article{osti_863946,
title = {Flash protection controller},
author = {Galbraith, Lee K.},
abstractNote = {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.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1981},
month = {1}
}

Patent:

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