Model train Identification Circuit

This circuit is intended to be used to detect trains on a model railway track. It is partially based on designs described in past issues of Elektor Electronics. As can be seen from Figure 1, it consists of a simple infrared transceiver built around an LM358 and an NE567. With the component values shown in the schematic, it has a working range of around 40 to 50 cm. When several detectors are used, crosstalk among the detectors can be avoided by setting the frequency of the NE567 to a different value for each detector. The LED and series resistor shown at the far right can be added to indicate that a track section is occupied.