Did you ever wonder how your roomba avoids the walls and furniture? You can thank the humble electromagnetic proximity sensor, which is able to detect the presence of nearby objects without any physical contact.
Electromagnetic proximity sensors play a key role in your life, whether you realize it or not. From the car alarms that wake you in the night to the aforementioned robotic vacuum, you likely come into contact with some kind of proximity sensor every day.
A capacitive proximity sensor (via Digi-Key)
In Short : This type of proximity sensors transmit an electromagnetic or electrostatic field and detect the physical presence of an object based on changes in that field. For example, proximity sensors located along most rollercoaster tracks measure position and speed of the cars, keeping everyone on the attraction safe and allowing ride operators to time the next set of cars.
Selecting the Right Sensor : Different targets demand different sensors. Inductive sensors, for example, are best for sensing metal objects where capacitive sensors can also detect things like liquids and plastics. Each type of sensor requires different information and provides different outputs, and it never hurts to ask for advice from others who’ve worked with similar sensors before you make a purchase.
Endless Possibilities : There is literally no end to what can be done with electromagnetic proximity sensors. Home alarm systems rely on proximity sensors, as do motion-activated lights. On the TechXchange forum, one user pondered using a proximity sensor to sense whether the grain-based feed in his downspout was running low. An aviation enthusiast considered adding them to the wings of his plane to prevent damaging the wings while moving the plane from its hangar.
Want to learn more or need help selecting the right proximity sensor? Post your ideas and questions on the TechXchange forum.
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