I have a Digitrax BD168 card that I will be using for block detection. I have all of the wiring diagrams planned out no problem, but have a question regarding what gauge wire to solder to the actual card edge connector. Digitrax states that the pins on the connector are designed for 20 gauge wire, which again is not a problem. But this raises a question: if I am using 12 gauge wire for all of my track bus wires, doesn't using smaller 20 gauge wire to connect the larger 12 gauge bus wires to the BDL168 compromise the use of the larger bus wires? In my mind, even a short section of 20 gauge wire between the booster and the rails basically limits that bus wire as if it was run entirely using 20 gauge wire. Isn't this pretty much how a fusable link works in automotive circuits? I know I must be missing something since I see 12 gauge bus wires and 20 gauge wires to the BDL168 used too many times to be incorrect.Thanks for any advice!Jamie
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CSXDixieLine But this raises a question: if I am using 12 gauge wire for all of my track bus wires, doesn't using smaller 20 gauge wire to connect the larger 12 gauge bus wires to the BDL168 compromise the use of the larger bus wires? In my mind, even a short section of 20 gauge wire between the booster and the rails basically limits that bus wire as if it was run entirely using 20 gauge wire.
But this raises a question: if I am using 12 gauge wire for all of my track bus wires, doesn't using smaller 20 gauge wire to connect the larger 12 gauge bus wires to the BDL168 compromise the use of the larger bus wires? In my mind, even a short section of 20 gauge wire between the booster and the rails basically limits that bus wire as if it was run entirely using 20 gauge wire.
A short length ( 3 - 12 inches) won't cause a significant amount of voltage drop in the system. Compare the wire size to those traces on the circuit board. This is where the old comparison of electricity and water pipes fall on its face.
Isn't this pretty much how a fusable link works in automotive circuits?
DCC is at lower current levels. The current is higher in an automobile circuit. The link's smaller gauge and length is calculated to deliberately burn out when that current level is exceeded. Again, compare your short section of 20awg wire to the short wire in a 20 amp automotive fuse. The 20ga wire only needs to carry a few amps.
Up to #18 will connect to the edge card - use short lengths and connect the free end to a terminal strip. I wired up a PM42 for the RCT&HS modular layout this way. The short lengths of the smaller wire won't cause any problems, and the terminal strip will give you a place to connect your heavy #12 wires (using spade or even better, ring, terminals) for both the input from the booster and the lines to the track blocks. I also used ring terminals on the ends of the smaller wire coming fromt he PM42.
The edge connector solder terminals are a bit delicate, avoid flexing things back and forth while connecting it all up. Once you secure the edge connector, board, and terminal strip to a piece of wood, nothign will move or flap around.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Thanks for the help gang. Got everything wired up nicely, but I have a problem when powering up. The BDL168 comes up just fine, but when I power up the DCS100 booster, I get 9 beeps and the booster goes offline. According to Digitrax docs, 9 beeps by the DCS100 means that something is mucking up Loconet. I have not started any debugging yet other than a thorough visual inspection of all the connections and wire routings. I wanted to post here before I break out the multimeter to see if anyone has any experience with this or similar issues. BTW, the BDL168 is the only Loconet device I have in the system other than booster/decoders. Jamie
WOO-HOO...EVRYTHING WORKS!!!
Sorry for the "all caps" announcement, but this is super cool especially for an uber-nerd such as myself. All I did was disconnect the Loconet cable from the BDL168 to the DCS100, powered up the booster, and everything ran just fine. I then plugged the BDL168-to-DCS100 Loconet cable back in and "voila!" the block detection kicked in perfectly. I even see the block occupancy messages coming in to JMRI via the Loconet Monitor as expected. I also powered everything down then back up, and everything comes up just fine without the 9 beep alert. Not sure what was wrong, but unplugging the cable and plugging it back in did the trick (loose connection???). Jamie
COuld be a bent pin in one of the Loconet jacks, either on the DCS or the BDL168. Did you use a different socket when you plugged it all back together and it worked? Check in each jack and make sure the 6 wire in each are in their own grooves and not lifted up.
Or maybe you just didn't have one of them snapped in all the way.