New Kato Mikado 3rd run engine

[u18b]

Bob, are those true dual throttles, or they share the same transformer internally?  What I'm leading to is whether for example they could be used with common-rail block wiring method, or will that cause a short when the direction switch in each throttle is set in opposite direction?

Pete,

I use one.  When you open it up there is only one transformer.

[nsbob]

Pete, I have not opened mine to look at the internals inside but each throttle has its own directional switch so one throttle works independently from the other.

[peteski]

Pete,

I use one.  When you open it up there is only one transformer.

So they are not isolated. I guess those are fine for 2 separate loops, or block control without using common rail wiring.

[peteski]

Pete, I have not opened mine to look at the internals inside but each throttle has its own directional switch so one throttle works independently from the other.

Thanks Bob!

[nsbob]

Pete I forgot to mention that when we used the TTRAK modules, we made sure that they did not have any crossovers so someone couldn't walk up and switch a train over to the other track.  Of course our modules have Kato Unitrack.

[mmagliaro]

Why can't you use the 2800 for a common rail system?   You wire the two negatives together out of the pack, and that is your common to the layout.  Then you run the two positives through all your block control switches (assuming you have blocks).   Sure, if a train goes from a throttle 1 block into a throttle 2 block and the direction switches aren't flipped the same way, you have a short, but that's pretty much the gig with DC common rail wiring.

[peteski]

Why can't you use the 2800 for a common rail system?   You wire the two negatives together out of the pack, and that is your common to the layout.  Then you run the two positives through all your block control switches (assuming you have blocks).   Sure, if a train goes from a throttle 1 block into a throttle 2 block and the direction switches aren't flipped the same way, you have a short, but that's pretty much the gig with DC common rail wiring.

There are no "negatives" to wire together from this type of throttle. Location of the "negative" on the track terminals depends on the position of the direction switches.  So if the direction switches are opposite, that will cause a short, even without a model crossing the block boundary.

If  2 separate throttles are used (each with its own isolated transformer) , the "negative" is "floating", so there will not be a short when the throttle polarities are reversed, even with both throttles not set to zero speed.  A short will only occur if a loco crosses the block boundary.

[randgust]

One of the smartest dumb things I ever did was to NOT do common-rail wiring on my layout (mid-80's design). 

Absolutely everything was wired with heavier-gauge wire, soldered, with multiple feeders and DPDT feeds to a master power bus.

There are two reverse loops and a double-track main, two cabs, so yeah, there's a lot of wire - a LOT of wire under there.   But it's evolved forward nicely into the DCC world without tearing much out, and being able to completely isolate a track section with the legacy toggles has been a huge bonus over the years as the inevitable glitches arise.   So even if you want to stay DC (and I have, really, on the main layout) I wouldn't lower your wiring standards to not be able to evolve forward if this is a layout you're actually considering keeping for a sustained period.

[u18b]

Well......
Since Pete says it's not possible.....
And since I was the source of info on the 2800....
And (not doubting Pete) I know for sure I used that throttle in a  common rail layout.....

I decided I would open it up and see if my memory was fuzzy and maybe there WERE two transformers in there.  (was there two little ones inside instead of one big one???)

But alas.... I can't find it.   It's either stored away ... or I gave it to Chessie System Fan.  I'll text Aaron some time today and see if he has it- though I'm not sure he has the tools to open it up if he does have it.  If he doesn't have a torx, he'll need the exact size flat blade to wedge in there.

[peteski]

I suppose that since probably not many modelers use common-rail block wiring we should probably not dwell on this.  I just wanted to mention that so someone  contemplating such wiring scheme would not use a MRC 2800 for it, but 2 separate throttles. Unless the 2800 has a transformer with 2 (isolated) secondary winding (which would be just like 2 separate and isolated throttles).   Let's not think about it anymore. 

[mmagliaro]

Well, Pete, what you say makes sense.  Except that I have now read accounts on line of people wiring the 2800 with the two "-" wired together as their common, and saying it still works fine when you flip the direction switches.  And the MRC instruction sheet for it says it is "completely compatible with common rail wiring" (who knows what "completely" means).  Something else must be going on in there.

HOW MANY WIRES are coming out of the single transformer?  It could have two independent secondaries.

--------
EDIT.  LOL!  The minute I posted this I saw that you wondered about it having two secondaries.    I betcha that's what they did.
There are plenty of dual-secondary transformers around, and that would cut down on so much cost and weight that I can't imagine
MRC not going that route.

[peteski]

Well, Pete, what you say makes sense.  Except that I have now read accounts on line of people wiring the 2800 with the two "-" wired together as their common, and saying it still works fine when you flip the direction switches.  And the MRC instruction sheet for it says it is "completely compatible with common rail wiring" (who knows what "completely" means).  Something else must be going on in there.

HOW MANY WIRES are coming out of the single transformer?  It could have two independent secondaries.

Usually 2 secondary wires, when used with a 4-diode full bridge rectifier.




Or 3 wires (the winding is center-tapped) with 2 diodes still resulting in a full-wave rectification.



If the 2800's transformer has either 4 or 6 wires on the secondary side than it is a dual-winding transofrmer, so each throttle is electrically isolated from the other.

[u18b]

I know this sounds like thread drift.....

But we're really waiting on Mike to get his hands on that loco and tear into it!!!
 

[peteski]

I know this sounds like thread drift.....

But we're really waiting on Mike to get his hands on that loco and tear into it!!!
 

YEAH!  Exactly!  We are just killing time in the meantime. 

[cjp53]

I know this sounds like thread drift.....

But we're really waiting on Mike to get his hands on that loco and tear into it!!!
 

My new Mikado came today and I talked to Mike,I mailed the first one back the same day Mike sent the other out.We had to babysit our Grandchildren today so I did not have a chance to run the new one but will do that tomorrow.I too am waiting to hear what he finds.