Circuitron 5201 DT-1 Grade Crossing Detector All Scale

The Circuitron 5201 DT-1 is an amazing all-scale grade crossing detector. It's a bi-directional detection circuit made for DC track power. Whenever a piece of rolling stock covers one of its Opto-Sensors, it gives an output. You don't need to modify the rolling stock at all. There are four Opto-Sensors, with 2 used for each travel direction. The two Opto-Sensors for each direction are wired in series, and there's a single sensitivity control for each direction to adjust according to different room light levels. The DT-1 connects to the track to figure out track polarity and only activates the Opto-Sensor set for that travel direction. This makes sure the output turns off right after the last car clears the crossing in either direction. The circuit board is 2” x 3” and needs a 10 - 18 volt AC or DC input to work properly. Using a filtered DC source will make the unit a bit more stable and easier to adjust. The output connects to the common or ground (-) side of the circuit and can control DC powered loads up to 250 ma. Note that the DT-1 can't detect a short train or single locomotive if it's between the Opto-Sensors, so the output will be off when the train is in that position. You can add an optional 3rd sensor to each side if you want, which will cut the minimum train length in half.

Using the Circuitron 5201 DT-1 is quite straightforward. First, connect it to the track to determine the track polarity. Then, the detector will automatically activate the Opto - Sensor set for the correct direction of travel. When a rolling stock passes over an Opto - Sensor, it'll give an output. You can adjust the sensitivity for each direction using the single sensitivity control to adapt to different room light. For power, you can use a 10 - 18 volt AC or DC input, but a filtered DC source will give you a more stable and easy - to - adjust performance. Just keep in mind that if a short train or single locomotive falls between the Opto - Sensors, the detector won't be able to detect it and the output will be off. If you want to detect shorter trains, you can add an optional 3rd sensor to each side. To maintain this detector, keep it clean and avoid exposing it to extreme temperatures or moisture. Regularly check the connections to make sure they are secure.