DocumentCode
836323
Title
A Fast-Response Dynamic Lightmeter and Its Application
Author
Peterson, Wesley G. ; Wolfframm, Bodo M.
Author_Institution
Sola Electric Company
Issue
4
fYear
1971
fDate
7/1/1971 12:00:00 AM
Firstpage
531
Lastpage
534
Abstract
A dynamic lightmeter is described. It has high gain, fast response, and is linear over a range of several decades. It is useful to present instantaneous light values on an oscilloscope or average values on a dc voltmeter. The instrument uses photodiodes in a differential circuit which balances the variation of dark current with temperature. In the high-gain position the overall frequency response is 125 kHz. Its sensitivity can be varied from 2 to 20 mV/fc. The application of the lightmeter is demonstrated on a special-purpose fluorescent ballast, operating from a 25-kHz square-wave source. The meter is used to observe start and decay times and steady-state operation of the lamp. Suggestions are made for calibration of the instrument and its application for closed-loop control.
Keywords
Circuits; Dark current; Electronic ballasts; Fluorescence; Frequency response; Instruments; Oscilloscopes; Photodiodes; Temperature sensors; Voltmeters;
fLanguage
English
Journal_Title
Industry and General Applications, IEEE Transactions on
Publisher
ieee
ISSN
0018-943X
Type
jour
DOI
10.1109/TIGA.1971.4181336
Filename
4181336
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