A simple proximity infrared detector circuit

This is a simple circuit for proximity infrared detector, based on proximity sensor? Infrared. The applications of this circuit are the most diverse. From placing them on the front door to prevent people from parking in front of the track, to even placing them on the back and front of the car to warn other drivers if they get too close to the park.

Circuit operation is based on emitting an infrared light signal that bounces off a nearby object and is received by another component. Upon receipt, the system detects proximity to the LED output which is activated (lights up).

This integrated circuit is a tone generator/decoder and serves the needs of this design well. Both photodiodes and phototransistors are placed in a suitable way to improve the range. Available range with simple LED reflector is meters. A distance of five meters can be covered using a convex lens. It is convenient to sacrifice some range but place a UV filter that does not let the phototransistor (receiver element) shine with sunlight.

The power supply for this circuit can be anything between 5 and 9 volts.

Driving an external circuit will be enough to replace the LED with an optocoupler that is controlled by its internal transistor circuit.