Robert C Burt (b. 1896), US physicist and inventor, with a photoelectric cell developed for use in burglar alarm systems. Photoelectric cells are used to convert light falling on them into electricity. In an alarm system, the absence of light falling on the cell and the resulting drop in electrical current triggers the alarm. | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / COPYRIGHT STATUS UNKNOWN / SMITHSONIAN INSTITUTION |
Taille de l’image : | 3404 px × 2573 px |
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Property Release : | Non requis |
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