Smoke Unit

Which type?  PS-2 or PS-1?  MTH DCS engines use PWM so the actual voltage is not known.  The combined resistance is 8 ohms, so the voltage is low.  G

For a PS/2 smoke unit, if you put more than around 6-7 volts on that unit, you'll have lots of smoke and a very short lifetime!

Why not connect it to a bench supply and slowly bring it up 1/2 volt at a time until you get the desired smoke performance.  You can simply wire the fan to 5V DC separately.  I think you'll find by the time you get to 6-7 volts, it's smoking you out of the room.

The PS/1 smoke units run off track power and have an internal regulator, so you can pretty much use any reasonable voltage from around 7-8 volts up to 16-18 volts.

We don't quite know yet why he wants to know the voltage.

PS-1 doesn't really have an internal regulator.  It kicks a second 16 ohm resistor in series with the first at a cross over around 12 to 14V.  This raises the overall resistance to 32ohms to compensate for the higher voltage present and still keep amperage down.  G

Well, controlling voltage is the definition of a regulator.

My point was that the PS/1 unit will run fine on a wide range of voltages, where the PS/2 unit operates over a very narrow range of voltages.

He did ask the voltage over which the heater operates properly, that's what I was providing.  I've done this on the bench with the PS/2 units so that I could use them in other than PS/2 locomotives without changing the resistors by using a regulator.  One of the cheap ebay switching power modules can be tasked to provide the heater power and adjusted to the proper voltage.

Folk

First of all, thanks for the replies.
Well, here we go:

GGG - in my case, it's PS-2 engine.
I'm trying to mount a Smoke Unit  without opening a locomotive to check the voltages.
After posting my question, I researched in OGR Forum - Search on the subject we're talking about.
I found good information, but would like to mention 03 of them who are excellent:

 
The first one was posted on October 22, 2011 by Alex;
He provided various information including photos for maintenance of the Smoke Unit

The second:  comment by gunrunnerjohn

Not much to go wrong with a PS / 2 or PS / 3 smoke unit, it's just a fan, a couple of resistors, and the wick.
He also provides MTH PS-1 Smoke Unit Schematic.

The third : Unit Smoke ohms? - posted on November 9, 2012 17:46

With excellent comments of Dale H and 

As I have mentioned above is worth reading those articles.

Finally, I will follow the suggestion of gunrunnerjohn;

Why not connect it to a bench supply and slowly bring it up 1/2 volt at a time until you get the desired smoke performance.  You can simply wire the fan to 5V DC separately.  I think you'll find by the time you get to 6-7 volts, it's smoking you out of the room.

Excellent idea.

Also wish to thank and mention the initiative of OGR Magazine / Forum have created a Database with very useful information.

Congratulations on your initiative.

Regards

A.C.sant Anna

Folk

Just complementing:

With excellent comments of Dale H and gunrunnerjohn

That was my point it doesn't regulate the voltage, it limits the current by boosting resistance  Antonio has his info though.

Antonio, I would also recommend you go to MTH service site.  They actually have service tips for their smoke units.  You don't have to do the mods to an MTH unit that you do to certain Lionel units from Alex post.  They also have the part numbers you need for service parts.  Good luck.  G

Glad you got what you needed, let us know how your project proceeds.

GGG and gunrunnerjohn;

Thanks for the information.

John I´ll keep you informed.

Regards

A.C.Sant Anna

Hi, John (gunrunnerjohn) and GGG

I proceeded with the test on my  bench work and below is the report:
Fan:  voltage applied 5VDC;

Heater elements voltage applied 6VDC.

RESULT: a lot of smoke.

Thanks for the support.

Regards

A.C.Sant Anna

I asked John the same question today and he was extremely helpful. Not that I am not capable of figuring these things out and doing the research but I am shrt on time thsese days so I appreciate it when I can get good info fast for a project I am working on, Thanks John I'll buy you lunch sometime

You guys are up and smokin'!

If you're coming to York Matt, I'll take you up on the lunch.