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Title: Light-operated proximity detector with linear output

Abstract

A light-operated proximity detector is described in which reflected light intensity from a surface whose proximity to the detector is to be gauged is translated directly into a signal proportional to the distance of the detector from the surface. A phototransistor is used to sense the reflected light and is connected in a detector circuit which maintains the phototransistor in a saturated state. A negative feedback arrangement using an operational amplifier connected between the collector and emitter of the transistor provides an output at the output of the amplifier which is linearly proportional to the proximity of the surface to the detector containing the transistor. This direct proportional conversion is true even though the light intensity is varying with the proximity in proportion to the square of the inverse of the distance. The detector may be used for measuring the distance remotely from any target surface.

Inventors:
 [1];  [2]
  1. (Harriman, TN)
  2. (Maryville, TN)
Issue Date:
Research Org.:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN
OSTI Identifier:
865448
Patent Number(s):
4516020
Assignee:
United States of America as represented by United States (Washington, DC) ORNL
DOE Contract Number:  
W-7405-ENG-26
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
light-operated; proximity; detector; linear; output; described; reflected; light; intensity; surface; gauged; translated; directly; signal; proportional; distance; phototransistor; sense; connected; circuit; maintains; saturated; negative; feedback; arrangement; operational; amplifier; collector; emitter; transistor; provides; linearly; containing; direct; conversion; true; varying; proportion; square; inverse; measuring; remotely; target; detector circuit; signal proportional; target surface; light intensity; reflected light; operational amplifier; proximity detector; negative feedback; detector containing; amplifier connected; direct proportion; feedback arrangement; light-operated proximity; /250/

Citation Formats

Simpson, Marc L., and McNeilly, David R. Light-operated proximity detector with linear output. United States: N. p., 1985. Web.
Simpson, Marc L., & McNeilly, David R. Light-operated proximity detector with linear output. United States.
Simpson, Marc L., and McNeilly, David R. Tue . "Light-operated proximity detector with linear output". United States. https://www.osti.gov/servlets/purl/865448.
@article{osti_865448,
title = {Light-operated proximity detector with linear output},
author = {Simpson, Marc L. and McNeilly, David R.},
abstractNote = {A light-operated proximity detector is described in which reflected light intensity from a surface whose proximity to the detector is to be gauged is translated directly into a signal proportional to the distance of the detector from the surface. A phototransistor is used to sense the reflected light and is connected in a detector circuit which maintains the phototransistor in a saturated state. A negative feedback arrangement using an operational amplifier connected between the collector and emitter of the transistor provides an output at the output of the amplifier which is linearly proportional to the proximity of the surface to the detector containing the transistor. This direct proportional conversion is true even though the light intensity is varying with the proximity in proportion to the square of the inverse of the distance. The detector may be used for measuring the distance remotely from any target surface.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1985},
month = {1}
}

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