Saturday, July 24, 2010

Power districts

Today -- well, yesterday mostly -- I finished a long-standing item on my to-do list: power districts.

The main benefit of districts is that derails in one area won't affect operation in another. Also, when the built-in booster of the Intellibox isn't sufficient any more, I can get one larger booster (say, 5 amps) and still limit the power draw per district to e.g. 2.5 amps, and limit any damage due to shorts.

I'm using the DCC Specialties PSX circuit breakers. They are very nice. Solid state operation, fail fast, very configurable. Can even be controlled by DCC accessory commands, and support POM.

Breaking up the existing layout into districts involved making several cuts in the rails in a somewhat hard to reach location. Another task I avoided for a long time. Now that the railroad is taking shape it was time to do it, since that location will be even harder to reach once the turntable goes in...

I planned for 3 power districts from the beginning, roughly corresponding to the 3 levels of the layout, and ran wires accordingly. Still, one surprise I ran into was that the PSX doesn't appear to play well with the Tam Valley Depot Servo controllers at the 1.27 power draw limit setting, so I installed the also long planned DCC accessory bus to the two controllers that need it, and hooked the new bus  straight into the main DCC power bus. That's a good thing no matter what, since I now can throw switches, even wile having a short in that segment.

Tomorrow (well, today really), I'll try to finally digitize the BR50, which has a fairly finicky wheelset, and run more tests to ensure reliable operation. Also, I need to make sure the railroad is operational for Sunday.

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