Need help modifying a PS1 smoke unit for PS3 upgrade

The object of the exercise is to get the two 16 ohm resistors in parallel.

John, Thank You Very Much!

Hi john,

    Just to confirm, I reconnect the ground wire that was under one of the black screws back under the black screw, correct?

Rich

There is no ground for the smoke unit wiring, so where does that wire go?  It's likely not used with the PS/3 upgrade.

Note that for PS/2 or PS/3 electronics, there are NO chassis ground connections except for the input track power on the 7-pin connector on the PS/2 or PS3/2 board.  You have to make sure no other connections get grounded, that will be very bad for the electronics.

Hi John,

      A picture is worth a 1000 words, so this is the wire I am speaking of, it runs to a screw holding the constant lighting board in place. There is another wire from the constant lighting board to the same screw. I have two ground wires, one in the tender and one in the locomotive.

Thank You Again!

OK, you'll want that one if you're using the CV board, it's just a ground.  The CV board has no connection to the PS/3 electronics, it gets track power and generates voltage for the lighting.

What engine is that?  Have you measured the resistor ohms of the smoke elements?   MTH PS-1 smoke does have an AC ground, but it feeds the PS-1 smoke electronic board.  Your smoke does not have the traditional PS-1 board.  So it is getting power from the CV board for smoke fan and it looks like the rectifier also for elements. 

The CV board is already grounded with the brown wire to the center mounting screw of the CV board.  So you need to remove that brown wire from smoke unit.  It looks like that is on DC side of the CV board.  Not 100% sure, but looks that way and needs to be metered.

Either way Johns advice on the Smoke PCB mod is right, but you better make sure the individual elements are 16 ohms, or the parallel connection reads 8 ohms.  I would remove the brown and orange wires to the smoke unit and trace where they wind up.  The Smoke switch on the engine comes out too and is part of that circuit.  G

George, I assumed, perhaps falsely, that the smoke unit was wired to the remote smoke control board, I see a lot of them I pull out of stuff wired with a remote board.

I found one in my parts box that is like his example with the thermistor and the resistors are 24 ohms!  Good catch on measuring those, they'll have to be swapped out for the proper resistors.   No damage would have occurred, but I suspect smoke performance wouldn't have been all that impressive. 

It appears this unit was designed to connect directly to track power and just the thermistor controls switching in the second element based on current through the smoke unit.

That is why I wanted model number.  I have only worked on one of those and it was so long ago I can't remember what it was.  As a tech we trace wires and have familiarity with AC versus DC.  His second picture showed fan and element attached to cv board.  Could very well have element attached to the AC connection side of the CV board, via the switch.  G

Just one more case where seeing it in the locomotive would have made it easy to verify what you have.   Seeing what the smoke unit actually consists of, it does seem that the CV board ran the fan and the smoke element connected directly to the track power.  I actually took that one out and tried it, worked great on track power with a DC supply for the fan.

Now that we know what we're dealing with, my modification instructions were valid, but the two resistors will also have to be changed to the standard MTH PS2/3 16 ohm resistors.

Sorry guys I have been neglecting my emails and just noticed you have been writing me.

This is a Premier New York Central Empire State Express from back in 95; model number MT-3016L.

Smoke output from the engine after the upgrade is pretty low; I was thinking it might need a re-wick from sitting the past 20 or so years, but maybe it does need the resistors replaced. Let me know what else you might need to assist.

As for the conversion all other locomotive functions are working as anticipated after an PS upgrade.

Thank You,

Rich

Measure resistance of smoke elements.  Should be 8 ohms in parallel.  If 12 or higher, those elements need to be replaced.  G

GGG,

   Do you sell those elements?

Rich

The resistors are the standard MTH 16 ohm smoke resistors, two in parallel is why you measure 8 ohms.  I usually keep them in stock.

Would be able to sell me two? I would just take the 4 screws off the top of the smoke unit to replace them correct? 

Rich 

Drop me an email to my profile address and we'll fix you up.

Hi Gentlemen,

I nave the the same problem that Rinzana1 had, regarding the circuit board of my smoke unit not being shown in the PS3 upgrade instructions.  I have a PS1 RailKing Allegheny, the box shows 20-1117LP, but the catalog # is 30-1117LP.  I've attached pictures of the smoke unit and engine.  I just need to know where to cut the circuit board for use with the PS3 upgrade.  I've been away from the hobby for quite some time and I'm in the process of making room for a layout so I won't be doing the upgrade immediately, I'm just trying to get the process established in my mind before attempting the upgrade.  Any assistance will be greatly appreciated.  

Thanks,

Steve

You remove the 3 wires and base electronic board.  Not needed.  Then ensure the resistors are in parallel by soldering the joint of the two elements as in the instruction.  Just make sure that once done you do not have a path to chassis ground by checking the continuity between element and the screw.  Can't remember if the light was using smoke house ground.  If so it has to be removed.  You just want the two elements isolated from anything else.  G

Thanks G. I wasn’t sure if I posted to the correct forum so I also posted this question on the PS3 forum page and got the same answer that you just gave (I think) from Gunrunnerjohn. I’m not well versed in electronics, but I follow directions pretty well. Thanks for the input. I’ll get back with you if I have further problems, probably via the other forum page. Thanks again, the people in this group are such a great resource. I’m so glad I found you!

steve