Model Railroad Electronics - Block Occupancy Detector

Description: Please Read the listing description before you place your purchase, thanks! In this listing, I have for sale a hand-made Single Channel Current Sensing Block Occupancy Detector. I have designed, engineered, crafted, modified, assembled, tested and packaged this product by hand in my workshop. I originally designed the first batch to express to model railroaders how the prototype signaling system works. As soon as I had finished the first batch, I had modelers demanding that I go to production and develop these for their layouts. HOW DOES IT WORK? It senses the electrical current going from one rail, to the other when something enters a block of track that conducts even the slightest amount of current through it. Something as heavy as a locomotive motor to something as light as a resistive axle with 39,000 ohms resistance. In fact, even a damp finger should trigger the sensor if you're doing it correctly. It does not use a transformer, so therefore it does not require winding your own coils. And most importantly IT'S NOT OPTICAL! So no cluttered layout with optic emitters and receivers, potholes and huge gaps between ties, funny looking not-to-scale trees to try and hide the optics... Modern prototypical railroads use a system very similar to detect and predict train movement within a block of track for highway grade crossings, wayside signals, drawbridges, remote controlled turnouts and many more functions. The chief difference is that their locomotives are either powered by a third rail or catenary wire, or by their own power plant, whereas most model railroads use a current provided in the rails to power the train. This makes it easy to detect the locomotives. But it does make detecting the cars a little more difficult only because your wheels are either isolated with an insulated bearing or they have non-conductive axles. Depending on how long or short your blocks are, you just need at least one of those resistive axles or locomotives in the block to trigger the sensor. If your shortest block is 18 ft and your largest train is 15 ft long, then you can get by with one resistive axle on the rear car. On the other hand if you are using my detectors to operate realistic grade crossing signals and want the signals to properly trigger and release, you'll want a resistive axle on the end of each car. For HO Scale, I can recommend http://jbwheelsets.com/resistor.html to provide you with quality wheels for all your model needs. I strongly recommend the 39k-ohm sets. AND WHAT DOES IT DO, EXACTLY? The detector provides a Logic High and Low status for microcontrollers such as Arduino, Raspbery Pi and so on. It also provides an ON/OFF connection for both the Clear and Occupied Statuses. The connection switches the Negative lead, leaving the positive as a common lead for whatever hardware you wish to connect to it. You can use it on Lamps or LEDs, Relays, servos, sound players and so on. For the simplest of applications, you can connect a Red LED to the Occupied lead, a Green LED to the Clear lead and your DC Positive to the Common Anodes of the LEDs. If the block is clear, the green light will illuminate. But if the block becomes occupied, then the red light will illuminate. It is strongly recommended against using the Digital outputs to drive LEDs in signals, or any kind of relay or motor. But the simplest answer to this question is that it will give you an electrical status as to whether a block of track is occupied or clear. What you do with that information is up to you because the number of applications for this device are as countless as the stars! WHAT SCALE MODELS WILL THIS WORK ON? So far, it's worked on Z, N, HO, S O, G and even 1-1/2” scale without any problem. It supports DC, Digital Cab Control, and AC-powered systems. (On systems like G and larger, the solution was to simply provide a power source such as a pair of AA batteries across the rails to show that there was something shunting the rails when occupied.) WHAT DO I NEED TO MAKE IT WORK? You will need a section of track, called a “Block” which shall be electrically isolated from other blocks of track. You'll need something on your equipment that draws power from the tracks, as explained earlier. You will also need an independent power supply that is not connected to your track power. A simple wall adapter will do. For Power options, please check out my power distribution board listings here: https://www.ebay.com/itm/194109834560 https://www.ebay.com/itm/194109833745 HOW COMPLICATED IS IT TO CONNECT?It really is just a matter of connecting the Track power to the detector, then the detector to your track. Provide your Detector with adequate “ISOLATED” DC power to the Aux Power In and you're done with the detector portion of this product. Now each time a train runs through the block of track, anything that conducts electricity will trigger the sensor and let you know the block is occupied. WHAT APPLICATIONS IS THIS PRODUCT GOOD FOR? Literally anything that requires the device to identify that a block of track is occupied and/or clear. Some of the most simple applications are for things such as: Grade Crossing Signals Wayside (CTC / ABS) Signals Station Stops Automatic Turnout Controllers Drawbridge Operation Dispatcher Control Operations It's simply a matter of applying the logic, where if the block is occupied or clear and you need an electrical signal to tell you so, this is the device you need. WHAT DO I DO WITH THE DEVICE ON MY LAYOUT? Mount it using the 4 1/8-inch holes on the corners and stand-offs so that the circuitry is not making contact with whatever you're fastening it to. You can purchase simple mounting hardware for this online at your favorite hardware supplier. If you have multiples of these cards, you can stack them to save space, using a 1-inch riser between each of them. They do not have to be stacked up in once central location unless that's your desire. There's nothing wrong with doing it that way if that's what you choose. But I recommend that you wire your track using a common bus and then the isolated rail(s) pass through the detector, which may require you to spread out your detectors along your layout. Take care to not run your wires more than 35 to 50 feet from the detector. If you have to run more than 50 feet of wire between your detector and the track or power supply, consider dividing up your power and track controls to multiple locations.

Price: 17.99 USD

Location: Big Sandy, Texas

End Time: 2024-08-08T02:00:45.000Z

Shipping Cost: N/A USD