{"product_id":"circuitron-800-5501-bd-1-block-occupancy-detector-opto-elect","title":"800-5501 BD-1 Block Occupancy Detector Opto-Elect","description":"\u003ch2\u003eBD-1 Block Occupancy Detector Opto-Elect\u003c\/h2\u003e\n\u003ch3\u003eDetails:\u003c\/h3\u003e\n\u003cp\u003eThe CIRCUITRON BD-1 is an advanced integrated circuit block occupancy detector designed to provide reliable, positive indication of track occupancy in model railway layouts. Using proven opto-electronic detection technology, it identifies the presence of any rolling stock within a protected block section without requiring modifications to locomotives or wagons.\u003c\/p\u003e\n\u003cp\u003eTwo pairs of CIRCUITRON opto-sensors are installed between the sleepers at each end of the protected block. When a train enters the section, it interrupts ambient light to the sensors, triggering the BD-1 logic circuitry and activating the appropriate block indication. The system is fully bi-directional, ensuring accurate detection even if a train reverses out of a block.\u003c\/p\u003e\n\u003cp\u003eThe BD-1 includes integrated driver circuitry capable of operating a pair of two-colour LED signals or incandescent lamps at each end of a block section. LED signals must be wired in a common anode configuration. The outputs are rated up to 250mA, providing dependable control for standard model railway signalling installations.\u003c\/p\u003e\n\u003cp\u003eFor larger scale applications, the BD-1HD variant offers heavy-duty output transistors capable of driving up to 500mA per output, making it suitable for high-power lamp-based signalling systems.\u003c\/p\u003e\n\u003cp\u003eThe BD-1 operates from a 10–18V DC filtered power supply. For unfiltered supplies, compatible options include CIRCUITRON PS-1 or PS-2 power modules. The unit is constructed on a compact 2\" x 3\" printed circuit board for easy installation.\u003c\/p\u003e\n\u003ch3\u003eFeatures:\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eOpto-electronic block occupancy detection with no rolling stock modification required\u003c\/li\u003e\n\u003cli\u003eBi-directional operation for accurate detection in all movement directions\u003c\/li\u003e\n\u003cli\u003eBuilt-in signal driver outputs for LED or lamp-based block signalling\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cbr\u003e\u003c\/h2\u003e\n\u003ch3\u003eAdditional Information:\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eInput voltage: 10–18V DC (filtered required)\u003c\/li\u003e\n\u003cli\u003eDetection method: Dual opto-sensor block occupancy detection\u003c\/li\u003e\n\u003cli\u003eDirectionality: Bi-directional detection capability\u003c\/li\u003e\n\u003cli\u003eOutput rating: Up to 250mA (BD-1 standard)\u003c\/li\u003e\n\u003cli\u003eSignal compatibility: Two-colour LED or incandescent lamp signals (common anode LED configuration)\u003c\/li\u003e\n\u003cli\u003ePCB size: 2\" x 3\" (50.8 mm x 76.2 mm)\u003c\/li\u003e\n\u003cli\u003eOptional variant: BD-1HD with 500mA heavy-duty outputs\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cbr\u003e\u003c\/h2\u003e\n\u003ch3\u003eMeasurements:\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eLength: 76.2 mm\u003c\/li\u003e\n\u003cli\u003eWidth: 50.8 mm\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Circuitron","offers":[{"title":"Default Title","offer_id":58557460251008,"sku":"CTN-800-5501","price":29.5,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0225\/2858\/9896\/files\/ctn800-5501.jpg?v=1785233247","url":"https:\/\/railsofsheffield.com\/products\/circuitron-800-5501-bd-1-block-occupancy-detector-opto-elect","provider":"Rails of Sheffield","version":"1.0","type":"link"}