Description
The Circuitron 5204 DT-4 Rolling Stock Detector is a simple photocell-based detection circuit — triggers an output whenever a piece of rolling stock passes over (or sits on) the sensor location.
What it does: Uses an Opto-Sensor / photocell between the ties to detect anything that blocks the ambient light — locomotives, cars, even an out-of-track derailment. Outputs a logic-level signal that can drive Circuitron flashers, the BR-3 bell, relays, or trigger automation.
- Detection method: Photocell / Opto-Sensor (between-ties)
- Output: Logic-level — drives flashers, bells, relays
- For: Industrial-spot detection, hidden-track occupancy, simple yard-arrival triggers
- Circuitron SKU: 5204 (Walthers 800-5204)
Tip: Cheaper than the DT-2 / DT-3 for situations where you just need to know 'something is there' — but doesn't include the direction / train-length logic of a real grade-crossing controller.
About Circuitron: A USA-made model-railroad electronics specialist (Maryville, Illinois) founded in the 1970s. Famous for the industry-standard Tortoise slow-motion under-table switch machine and its surface-mount cousin the SMAIL. The full range covers detection (block detectors, Opto-Sensor grade-crossing logic), automation (auto-reversers, external relays, twin-coil alternators), signal / lighting electronics (alternating flashers, ditch-light oscillators, strobe drivers), power supplies, and a complete set of Tortoise / SMAIL replacement parts plus the solderless ZipZ connection system. Most circuits work with AC, DC, or DCC track power unless specifically noted otherwise.
In stock at Oakville Model Trains Depot.