beginner electronicsWhat Is a Photocell? Simple Light Sensor Guide
Learn what a photocell is, how light changes its resistance, and how to teach this simple sensor in a beginner STEM circuit...
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Teaching notes, project walkthroughs, and hands-on electronics guides from Gary and the Mr Circuit team.
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Updated Jun 29, 2026
light sensorHow a Light Sensor Works in a Robot
Learn how a light sensor works in a robot by measuring brightness or reflection and turning that signal into a classroom-friendly action.