About 10-years ago, I dismantled an HO layout on which I had successfully installed a Circuitron DT-4. Essentially, when a train in a hidden staging track covered an optosensor, an LED on the control panel lit.
Now I am attempting to reinstall it, and I don't have any of the instructions. What I have in front of me is a Circuitron PS-1, a Circuitron DT-4, and a two cell "D" size battery holder. The negative side of the battery holder is soldered to the negative output from the PS-1.
Here's what I think - and if anyone reading this has just a smidge of electronics knowledge, please correct my thinking....
1. Power into the PS-1 comes from the AC terminals of a power pack;
2. Output from the PS-1 is the power input to the DT-4;
3. Each of the optosensors has one lead connected to a numbered "S" terminal on the DT-4, and the other lead of all four sensors are connected to "SD";
4. The negative lead from an LED is connected to a numbered "O" terminal on the DT-4, and all the positive leads from the four LEDs are connected to the positive side of the D-cell batteries.
Thanks to anyone who can help!
Maybe this link will help.
http://trains.com/mrr/default.aspx?c=a&id=1845
Thanks, Brad...
The linked diagram confirms that the "SD" post is the "common" for the sensors, so I'm confident that statement #3 in my message is correct.
I really appreciate the help!