Friday, June 29, 2007

I had a few extra minutes before my meeting last night, so I was able to test the IRDOTs. They all work fine. All I need to do now is install the bi-color LEDs in the panel and wire them. But that brings up another problem...

When I first built the panel, I didn't plan on having much in the way of indicator lights, except for occupancy indicators for the hidden yards. But it turns out that it's easy to get confused about which track is selected for Minneapolis staging! Since the ladders for that yard are not mirror images, making sure the same track is selected for both ladders is not completely straight forward. In fact, even though I built both the yard and the panel, I have to look twice and think for a second or two to make sure I have the right track selected at both ends! So I want to put in an indicator for which track is selected for each ladder, with the simple premise that only the indicator for the selected track will light (for each ladder), with other indicators dark. An easy, at-a-glance way to be sure that the right tracks are selected at each end of the yards.

Note that I'm not looking for an indication of how the turnouts are actually aligned, only of which way the panel switches indicate the turnouts should be aligned. Simple to do, except...

The tortioses are thrown using DPDT switches. For my "selected track" indication, I need 3PDT switches - two sets of poles for the Tortoises, and one for the indicators. So I need to disassemble the panel, remove the DPDT switches, and install the 3PDT switches in their place. OY!

Meanwhile, I'm just a bit leery of installing the bi-color (red/green) LEDs for the IRDOTs, just in case I need a bit more room for the track selection (blue) LEDs. But maybe I'll just bite the bullet and put in the occupancy LEDs anyway.

Here's how the panel looks now:

Thursday, June 28, 2007

Been so busy with borough meetings and so on (plus stripping the porch in preparation for painting) that I haven't been able to work on the layout for several days.
Last night, though, I did have some time (no meetings!), so I got back aboard the creeper and spent two hours underneath the layout wiring the IRDOTs. Other than adding a couple of cable clamps, the under-layout work is done for now. I'm going to try to test the IRDOTs this afternoon, but that's doubtful - I have another meeting tonight! But if they work, then all I have to do is install the LEDs in the panel and wire them up - probably three to six more hours of work. Maybe by Sunday night...

Saturday, June 23, 2007

I managed to finish mounting the first group of IRDOTs last night. My back is still a bit sore, so getting on and off the creeper was not a lot of fun! Now comes wiring. I'm using bi-color LEDs, so each IRDOT gets four wires run to it - two for power and one for each color of the LED. Power is common on all units (wired in parallel), so I need 12 wire cable - two to each IRDOT, for ten wires, and two to all IRDOTs for power, making two more for a total of twelve. And gee, I'm just lucky enough to have bought a spool of twelve-conductor cable from Digi-Key when I was wiring Tortoises. Sometimes things DO work out. I'll be starting the wiring tonight. That should take several days.

Sunday, June 17, 2007

It's been a few weeks since I last posted any activity - because there's been very little activity.
Since the end of May I've been too busy with other things (the local primary elections, some irritating back problems that's made me less than completely comfortable working around the train, etc.) to spend time on the layout. But the last few days I've managed to start again - slowly.
I got the feeders installed on the track west of Genrock, and extended my layout power circuit (I have a 120V line running along the front L-girder of the benchwork, with outlets spaced conveniently every 8 feet or so). I hope later this week to start installing the rest of the IRDOTs on the west end of Milwaukee staging, but that kinda depends on how my back is feeling.