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ERIC Number: EJ926907
Record Type: Journal
Publication Date: 2011-Mar
Pages: 4
Abstractor: As Provided
Reference Count: 11
ISSN: ISSN-0031-921X
The Light-Emitting Diode as a Light Detector
Baird, William H.; Hack, W. Nathan; Tran, Kiet; Vira, Zeeshan; Pickett, Matthew
Physics Teacher, v49 n3 p171-174 Mar 2011
A light-emitting diode (LED) and operational amplifier can be used as an affordable method to provide a digital output indicating detection of an intense light source such as a laser beam or high-output LED. When coupled with a microcontroller, the combination can be used as a multiple photogate and timer for under $50. A similar circuit is used as a data logging system for a mirror galvanometer, providing a record of changes in the Earth's magnetic field as small as a few nanotesla (nT).
American Association of Physics Teachers. One Physics Ellipse, College Park, MD 20740. Tel: 301-209-3300; Fax: 301-209-0845; e-mail:; Web site:
Publication Type: Journal Articles; Reports - Descriptive
Education Level: N/A
Audience: Teachers
Language: English
Sponsor: N/A
Authoring Institution: N/A