Circuitron #800-5202 DT-2 Bi-Direction Grade Crossing Detector ModuleThe Circuitron DT-2 is an advanced, integrated circuit design, logic type detection unit for grade crossings. The DT-2 operates on a photoelectric principle with tiny Opto-Sensors that mount between the ties. In addition, the DT-2 incorporates track polarity detection for bi-directional applications and will provide fully automatic operation for all scales utilizing 2 rail DC operation. This advanced circuitry closely duplicates prototype grade crossing action. The DT-2 can also provide bi-directional operation for AC or command control track power, however, the train direction must be manually set from the panel. The output terminal on the DT-2 provides a connection to ground (-) when the train is detected. The output can control any DC powered device with a current draw of 250 ma. or less. The DT-2 does not include crossbuck flashing circuitry. A Circuitron FL-2 or FL-2HD should be used along with the DT-2 for a complete installation (sold separately)