PS2 Dual Smoke Units

If you wire two smoke units in series, they will each get only half the voltage they need for proper operation.  Since the heater and the blower motor are wired separately (the motor gets pulsed to emit chuffs), you would have to wire the blowers in series and the heaters in series.  If you wired the heaters in parallel and the blowers in parallel, I expect that the doubles current draw would be too much for the board's circuitry.

On the prototype, steam from the tender's cylinder came out of and exhaust on the tender, but would not have contained smoke from the fire.  If you  really want smoke from the tender, and think of it as steam, you could wire up an 18-volt smoke unit directly to the rollers, and it would always be on when the track is powered

I don't know why the underlining in the last post

I thought series wiring summed the voltages but that I think that only applies with power sources now that I think about it. Having a fixed voltage and wiring the draw in series makes sense that it would halve the voltage. 

Annnnyway I would like to have something just because it's cool and the engine is interesting. I was wondering how the heck they got smoke from the fire back there and I figured it must be steam exhaust so thank you for confirming that! I wonder if I could find a way to make it chuff with a little timer circuit. I was just hoping the PS2 board would do the work for me but we'll see. There's a fair amount of real estate in the tender so maybe I can come with something now that I know I can pick up power from the rollers. 

It is said that one of the problems in the Triplex was insufficient steam, due in part to the fact that steam from the third set of drivers did not exhaust up the stack and therefore did not contribute to draft to enhance the fire.

Personally, I avoid model loco smoke because it cannot be healthy to breathe that material

That's interesting. Gotta wonder what it could have with some mods. Probably still couldn't keep up with diesels in terms of cost. It'll definitely look cool hauling coal drags for me. I'm considering a two level layout so it might even find itself doing prototypical helping. But we'll see. 

I would have to look up the ingredients before I decided if I felt it was or wasn't healthy. I think it's oil. So probably not good haha

The 3V PS/2 board supports two smoke units, just wire them in parallel.  Note that the chuffing will be in sync between the two.

I assume that means that the available MTH smoke units all pull the same voltage? Is there a recommended way to attach the wires to the same 4 pin connector? 

It's too bad the programmable chuff generator won't work for this application! But I would rather have an incorrect chuff than no chuff at all

I would not assume that all of the MTH smoke units made over the years operate at the same applied voltage, nor that they all draw the same amperage.  I recall that many years ago when doing an upgrade I had to do some rewiring of the resistors on the unit.

Given your statement that you are electrically challenged and from the terminology you have used, might I respectfully suggest that you postpone this project?  One misstep and you could irreparably damage the PS2 board

GRJ, I read your last post after posting the above.  I suggest you describe in detail how he should wire the blowers and heaters

I attached a picture of how I think it should be wired. Obviously there are colors involved but I think that what I drew is parallel. The tender unit would be attached to the boiler unit if it was in series. I think. 

Sorry for crossing the wires right off the bat. I hope the idea comes across anyway. 

EDIT: I showed the end of the 4 pin connector coming from each unit because I think there's only one 4 pin on the board to connect to. I don't know if I'll be crimping a new 4 pin connector with 8 wires or if I'll have to make connections elsewhere and bring them to the connector. 

All the standard sized PS/2 and PS/3 smoke units with two resistors are equipped with two 16 ohm resistors in parallel.  If you're doing an upgrade and using a PS/1 smoke unit, then you have to do a bit of chopping and jumpering.  They also have two 16 ohm resistors, but they are not wired in parallel as they're switched by the basic regulator circuit on the PS/1 smoke unit PCB.  Once you do the mods called for in the upgrade manual, you treat them just like any other PS/2 2-resistor smoke unit.

That being said, subject to the above observations, they're wired 1:1 in parallel.

Sounds like the easiest path is to find a PS2 or PS3 smoke unit. 

My confusion on the wiring came from having a 4 pin connector. I'll check out the upgrade manual again and see what it says about the conversion and what wires control what.

EDIT: I looked over the upgrade manual real quick. I see what you mean about parallel and how they want you to modify the circuit. That doesn't look as bad as I thought it would be. I think I could handle that. 

It's not that hard.  Truthfully, what I've done with a number of them is just take the PS/1 smoke unit board and cut it off right at the end of the fan chamber to remove all the circuitry.  Then make the mods to the PCB that's left.

Cool. I ordered a unit. We'll see what goes when it arrives. 

I finally got my hands on a smoke unit. It should be a PS2 smoke unit if I did my homework right. It's got the two resistors wired in parallel so no chopping is necessary. 

Unfortunately, I over-estimated my real estate by a lot. I'm going to have to chop the legs off this smoke unit and I hope that works. I'm not even convinced that will get me in the ball park but I plan to make a little cardboard mock up of the space I need to fit the legless smoke unit. I'll either need a smaller unit or I'll need to get very creative to make it work. 

After that, I plan on checking the PS2 upgrade instructions if I don't see where the stock smoke unit plugs in. Then it's just wiring them up in parallel like the picture above and doing a little drilling and plumbing to get the smoke out of the tender, and we're good!