Lecture
This lecture discusses the principles behind a rain sensor used in vehicles, focusing on optical detection methods. The instructor explains the concept of total reflection in glass and how it can be manipulated to detect rain. By using a half-sphere on the glass surface, the lecture illustrates how light transmission changes, leading to a reduction in light intensity on the reflected beam. The design of the rain sensor involves sending light through the car window, where it reflects multiple times before being detected by a photodiode. The presence of rain alters the light transmission, allowing the sensor to determine when to activate the windshield wipers. The lecture also references a specific rain sensor produced by Bosch for use in Peugeot cars, highlighting the practical application of these optical principles in automotive technology.