Homemade Proximity IR Sensors

The same technology in remote controls can make proximity sensors.

Proximity sensors detect when something comes within a certain distance, or proximity, of the device. The function of these sensors can serve several purposes for homemade devices.

Mechanics

The sensor works through the reflection of infrared (IR) light the sensor emits. When something gets close enough, it reflects the light the sensor is emitting back into the sensors, and triggers the appropriate circuits to indicate something or someone within the predefined proximity.

Construction

To build a proximity IR sensor at home, you need an infrared transmitter, a photodiode detector, photodiode amplifier and a variable threshold comparator.

Uses

Proximity sensors can be used in many projects. They are useful in home robotics projects, with the device being capable of detecting its proximity to a wall or other solid object, and for use in security systems.

References

• Explore Circuits: Proximity Sensor

Resources

• Explore Circuits: Proximity Sensor Schematic