{"product_id":"circuitron-5204-dt-4-rolling-stock-detector","title":"Circuitron 5204 DT-4 Rolling Stock Detector (Photocell-Based)","description":"\u003cp\u003eThe \u003cstrong\u003eCircuitron 5204 DT-4 Rolling Stock Detector\u003c\/strong\u003e is a \u003cstrong\u003esimple photocell-based detection circuit\u003c\/strong\u003e — triggers an output whenever a piece of rolling stock passes over (or sits on) the sensor location.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat it does:\u003c\/strong\u003e 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.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDetection method:\u003c\/strong\u003e Photocell \/ Opto-Sensor (between-ties)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOutput:\u003c\/strong\u003e Logic-level — drives flashers, bells, relays\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFor:\u003c\/strong\u003e Industrial-spot detection, hidden-track occupancy, simple yard-arrival triggers\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCircuitron SKU:\u003c\/strong\u003e 5204 (Walthers 800-5204)\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eTip:\u003c\/strong\u003e 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.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eAbout Circuitron:\u003c\/strong\u003e A USA-made model-railroad electronics specialist (Maryville, Illinois) founded in the 1970s. Famous for the industry-standard \u003cstrong\u003eTortoise\u003c\/strong\u003e slow-motion under-table switch machine and its surface-mount cousin the \u003cstrong\u003eSMAIL\u003c\/strong\u003e. 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 \u003cstrong\u003eZipZ\u003c\/strong\u003e connection system. Most circuits work with AC, DC, or DCC track power unless specifically noted otherwise.\u003c\/p\u003e\u003cp\u003eIn stock at Oakville Model Trains Depot.\u003c\/p\u003e","brand":"Circuitron","offers":[{"title":"Default Title","offer_id":45098465198262,"sku":"800-5204","price":70.68,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0718\/5131\/1286\/files\/57_bd2ebd2c-64e9-405f-91d5-87c751060497.jpg?v=1779570065","url":"https:\/\/oakvillemodeltrains.com\/products\/circuitron-5204-dt-4-rolling-stock-detector","provider":"Oakville Model Trains Depot","version":"1.0","type":"link"}