The Circuitron DT-4 provides the modeler with an ideal system for spotting a train or even a single piece of rolling stock in a hidden location. The DT-4 actually contains four completely independent detection circuits com-bined onto one circuit board. Each of the separate sections may be used alone or in conjunction with each
other at various points on a layout. The DT-4 utilizes our proven Opto-Electronic principle and provides a signal at one of the output terminals whenever the corresponding Opto-Sensor is shaded from the ambient room light by a piece of rolling stock. Independent sensitivity controls are provided to adjust each of the 4 circuits to varying lighting conditions. The DT-4 can be used for any scale and will detect all powered and unpowered rolling stock with no modifications necessary. Each output on the DT-4 provides a connection to ‘negative’ (ground) when the Opto-Sensor is covered and the output is ON. Like all CIRCUITRON Detection circuits, these outputs will each control up to 250 ma. of DC accessories or lamps. The DT-4 is constructed on a 3” x 3” printed circuit board and requires a 6 – 20 volt DC power source. For greatest stability and ease of adjustment, the power supply should be filtered or regulated.