DCC is just weird......

[5150WS6]

Ok so here's the thing.  I have a NCE DCC layout.  First DCC and first layout we've done in 25 years.  So new guy here.  Now that statement made.....the layout is working fine for the most part. 

But today I had the multimeter out checking things.  I had it on ohms to check to make sure my frogs weren't touching or to make sure they were indeed isolated.  Something weird happened. 

When I touch the inside rail.....and then another inside rail the ohm meter showed connected.  Good right?

Then when I touched the inside rail and the outside rail......connected?!?!?!  What the heck?  Is that normal? 

This was with the system off obviously.  And the NCE has a built in short out feature.  But when I plug it in, no short.  And it works perfectly. 

So is this normal?  I would think no.  But then again, it all works flawlessly.  So am I just sort of clueless and this is how DCC works?

Mike

[moelarrycurly4]

Was it totally 0 ohms or was there some resistance showing, ?

The transformer driving the voltage for your track will show continuity through the seconday outputs ( your two rails) So yes normal. low enough to make your meter prob beep when checking with ohm meter. 

 

[retsignalmtr]

If it ain't broke, don't fix it. Read up on DCC and its peculiarities. most times you will learn by doing.

[gregc]

5150WS6

Then when I touched the inside rail and the outside rail......connected?!?!?!  What the heck?  Is that normal?

you're also measuring the resistance throught the NCE output circuit.   It's not obvious what that resistance is thru an unpowered circuit.   Mosfets look like diodes when polarity it reversed.

It may be useful to be able to conveniently disconnect the command station from the track to perform the test you did.   

[5150WS6]

That's a good thought too.  Like I said all is normal and I don't want to go poking around places I shouldn't, especially when things work just fine!  LOL!  I'll unhook the NCE and see what it reads then.

MoeLarryCurly, it was showing some resistance.  Which I didn't think it should have been.

Mike

[rrinker]

 You'd get a similar sort of thing with a transistor DC power pack, depending on which way you connected the meter leads to the rails.

                                     --Randy

 

[richhotrain]

5150WS6

When I touch the inside rail.....and then another inside rail the ohm meter showed connected.  Good right?

Then when I touched the inside rail and the outside rail......connected?!?!?!  What the heck?  Is that normal? 

I would be interested in knowing the brand and type of turnout that you used for the test and where exactly on the turnout you placed the two multimeter probes for this continuity test.

Rich

[BroadwayLion]

LION has double crossover switch. Compleatly dead. Isolated, no wires on it at all. With 48 wheel pick-up on subway trains of him, futzing with powered turnouts is not necessary

 

PHFFFfffffttttttttt.

 

 

 

ROAR