01-07-2010, 10:07 PM
So.
I've been filling some "holes" in my track work using some PCB ties that have an isolation gap in them. When I power up the layout, everything is fine, no shorts. Power Cab boots up, locos run, Torts are just peachy. When I do a test by dropping a piece of rail across the rails I get hard short...which is good. Its what you want to happen. I've heard it called the quarter test in couple of different places... anyways...
When I use a VOM on the rails with the DCC off (or even on for that matter) the VOM reads a dead short. Is there any particular reason for this? Is it because that even when powered off the sum of the parts, i.e. layout wiring, track work, decoders, electronic tidbits, DCC system create a circuit that allows the VOM to see (perhaps what it "thinks") is a dead short?
Does that make any sense? I've just never tested the track work installed and on the layout like this, only on the bench, and wonder if there is a logical explanation for it.
Otherwise, I'll keep plugging ahead and accept it as normal.
I've been filling some "holes" in my track work using some PCB ties that have an isolation gap in them. When I power up the layout, everything is fine, no shorts. Power Cab boots up, locos run, Torts are just peachy. When I do a test by dropping a piece of rail across the rails I get hard short...which is good. Its what you want to happen. I've heard it called the quarter test in couple of different places... anyways...
When I use a VOM on the rails with the DCC off (or even on for that matter) the VOM reads a dead short. Is there any particular reason for this? Is it because that even when powered off the sum of the parts, i.e. layout wiring, track work, decoders, electronic tidbits, DCC system create a circuit that allows the VOM to see (perhaps what it "thinks") is a dead short?
Does that make any sense? I've just never tested the track work installed and on the layout like this, only on the bench, and wonder if there is a logical explanation for it.
Otherwise, I'll keep plugging ahead and accept it as normal.