Fixing Seuthe Smoke Units

There is no "fix" to a Seuthe smoke unit, when they fail you replace them.  There's nothing to fix.  There may be a power board that is the issue, or perhaps a loose wire?  The Lionel ones I've seen use a 12V Seuthe smoke unit, most of the Williams and Weaver locomotives use a 6V model.

I have two Williams Pennsylvania S-2 Turbine 6-8-6 Engines which have, I believe, Seuthe smoke units.  The units seemed to smoke fine for the first few days.  Then all of a sudden they just stopped smoking.  I used the fluid which came with the engines and I don't think I over filled them.  I took out one of the Seuthe units and measured the resistance and it was around 49 ohms so I am thinking the unit is not burned out.  So what is the problem with the unit and why did it fail? 

I see Gunrunnerjohn says the only "fix" is to replace the unit.  But without knowing why these units failed, I don't think it is economical to replace the units if they might fail again after a few days.

I've seen some comments that say as long as the resistance of the unit is between 10 and 100 ohms, then there is hope to revive  the unit.  Anyone know if that is true and, if so, how do you do the reviving?

I know of no way to revive a Seuthe smoke unit.  They are a sealed assembly.  The two working ones I have in my parts box from Williams upgrades measure 8 and 10 ohms.  I seriously doubt one measuring a significantly higher resistance will ever come back to life.

The primary reason they would fail is running them dry for an extender period of time or running them at a significantly higher voltage than the 6V design voltage for the ones that Williams uses.

By the way, how in the heck do you pronounce "Seuthe"?

"Funny sounding tubular smoke unit".

TrainsRMe posted:

By the way, how in the heck do you pronounce "Seuthe"?

Most Americans pronounce the word "Sooth" with a soft th as in "soothsayer." But, it's actually a German word, and in German it would be "ZOY-tuh." Take your pick. 

I believe that John is right in that these cannot be repaired but while surfing around a few months ago to get more info on Seuthe I came across this thread.

http://www.newrailwaymodellers...ewtopic.php?p=180324

what I found interesting is these don't fail from using too much fluid but from letting it go dry. It implies that engines that use them should have an on/off switch or else you can't ever let them run dry.

Pete

That looks like the hard way to build a smoke unit, I think I'd install a fan driven one.

Thanks everyone for all the good input. 

I suppose my units probably went dry while I was running the engines. But there is no switch on the Williams engines (at least that I am aware of) to turn the unit off.  So if there is no switch to turn the unit off does that mean that the manufacturer really expects me to use fluid every time I run the engines?   Doesn't seem real practical to me.  I realize I could wire in a switch myself but why wouldn't the manufacture include a switch if they felt the unit really needed to be shut off when there is no fluid in the unit?

Something else that I noticed is the unit is plugged into a constant voltage pc board which also drives the head light.  When I measure the DC output voltage from the board it is around 7.8 volts.  If the Seuthe unit is suppose to be run at 6 volts could the 7.8 volts be too much for the unit?  (Again, why would the manufacturer use 7.8 volts if that causes a problem with a 6 volt unit?)

One other question I have is if a good working unit is around 10 ohms, what causes the resistance to go to just 49 ohms?  It would seem to me if the unit fails because it burned out, wouldn't the resistance be infinity (infinite resistance)?   With 49 ohms of resistance there would still be some current flowing through the unit but only about 1/5 of the current flowing through a unit which measures 10 ohms, so probably not enough to heat of the unit.  But I still wonder why there is any resistance at all instead of infinite resistance?

What Williams engine do you have with no switch?  All the ones I've pulled them out of in upgrades have a switch for the smoke unit.

I don't know the exact failure mechanism, so I can't say why they don't to to infinity.  I do know that 49 ohms with 6 volts would give you less than a watt, and that will equal no smoke!

For background, lots of empirical data on different smoke units here: http://girr.org/girr/tips/tips3/smoke_tips.html

Of note are smoke units that detect dry condition and automatically shut off.  I didn't see a DIY but maybe a chamber over-temp cut-off sensor or occasionally measuring heater resistance assuming the Ohms changes with temperature as most resistors do.

I hasten to point out that all, or at least most of the Williams Seuthe units are driven by a 6V regulator, so they're actually 6V units.  I do like the idea of possibly sensing the lack of fluid, though I have no idea how effective it might be.

One of the engines is a Williams S2-103 Pennsylvania Silver S-2 Turbine 6-8-8 engine.  And the other is Williams S2-100 - 6-8-6  #671 Turbine.  They are basically the same engine.  The smoke unit plugs into a PC board with no switch in the connecting wires.  The headlight also plugs into the same board.  The two plugs connect to two sets of pins on the board.  These two sets of pins are wired in parallel on the board so if there is some switch up stream it would also switch off the head light when the smoke unit is switched off.

I think my volt meter is fairly accurate and it shows a constant voltage coming from the pc board of 7.8 volts DC - not 6 volts.  The two engines were bought in different years and the digital whistle in the tender is a different digitized sound.  So apparently there was no attempt by the manufacturer over the various production runs to reduce the output of the pc board.  So they must have felt that the 7.8 volts was acceptable. 

Can you show us a picture of the board?  Specifically, I'd like to know what numbers are on the regulator on that board.  7.8 volts doesn't sound like it would be a design voltage.

Sorry it took so long and I don't have a picture yet. but the only number I see on the pc board is: 1023-X004.  There is another number which I think is the mfg date - 2000.06.15. 

Basically the board has 4 diodes, an electrolytic capacitor, and an IC chip mounted on a heat sink.  I assume that is a voltage regulator.  I'm going to have to get a better light and a magnifying glass in order to read the numbers on the chip.

Mike H posted:

 I assume that is a voltage regulator.  I'm going to have to get a better light and a magnifying glass in order to read the numbers on the chip.

I'm predicting the numbers 7808 ...

Despite looking like everything is wired in parallel, most units I have seen run a wire to a switch so that power can be interrupted to the smoke unit only.  Even saw one that went all the way back to the tender.

Not to say a more modern and recent WbB doesn't have a switch.

Early Williams used 6V reg, I have seen later ones with 8V reg.   G

Here are some pictures of the CV board.

  This is from the S2-100 engine I bought some years after I bought the S2-103.  Apparently there were some changes from the S2-103 to when I bought the S2-100 even though the board number is still 1023-X004.  The cv chip on the board in the S2-100 is a 7806 AND it's output is 6V DC.  The cv chip in the earlier S2-103 is a 7808 and is the chip I originally measured.  The voltage on this chip is 7.8v DC.  This is the engine that won't smoke and the smoke unit measures 49 ohms.  Interestingly the operating instructions that came with the S2-103 says a replacement headlight should be a 6V grain of wheat bulb even though the headlight plug is right next to the smoke unit plug (lower left corner of the above picture). Both sockets on the board seem to be connected together.  Here is a picture of the under side of the board.

The two sets of pins for the two connectors are in the lower right corner of this picture (the four solder points in a horizontal row at the bottom right of the picture) The left two pins are one connector and the two right hand pins are the other connector.   You can see there are only two foil strips connecting the four pins - one strip connects the outside two pins together and the other strip connects the center two pins together.  Thus the two sockets are in parallel.  So it seems to me that any switch up stream that would turn off the smoke unit would also turn off the headlight. (Also, there are no wires between the engine and tender so there is no switch in the tender).

I guess my question now is if the Seuthe unit in the S2-103 (which doesn't work) is designed for 6v would running it off 7.8v cause it to fail?  Both engines came with small Christmas gift type tags which had a warning not to use any other smoke fluid other than Williams (the S2-100 tag said "LGB or Seuthe") fluids or else the smoke unit may "plug up". These special tags lead me to believe Williams was having a lot of owners experiencing problems with the smoke unit not working.

All the Williams stuff I've taken apart for upgrades have had 6V boards and 6V Seuthe smoke units.  It's odd that they'd specify a 6V bulb for an 8V regulated output!

Running a 6V Seuthe smoke unit on 8V will greatly shorten it's life, and it might kill it within a few minutes.  If you run the 6V unit on 6V, it dissipates about 3.6 watts.  However, running it at 8V will rocket the power dissipation to 6.4 watts, almost twice the nominal power!  That can't last long before it dies.

Yes, those were the numbers I was coming up with also. 

One interesting thing about the CV chip in the S2-103 is that on the chip it said 7808CV  but below that it was marked 6V.  But, as I said, the output measures 7.8v which would agree with the 7808 designation.  Could it possibly be that Williams thought it was putting in a 6v voltage regulator (hence the 6 volt headlight bulb) but, in reality, was outputting 8 volts?  Or perhaps there is a Seuthe unit that is rated for 8v???  Is there any possibility that the chip they put in was a 6v regulation unit but that somehow it failed and started outputting 7.8 volts???

But if the unit was a 6v unit and it did fail because of the higher voltage (and thus higher amps and watts) would not the unit measure "open" rather than 49 ohms?  If the unit did fail because of the wrong voltage is there any chance the Williams/Bachmann would replace the unit?  Of course the regulator would need to be changed, and then there is the whole issue of why there is no shutoff switch if the unit cannot tolerate running dry.

All good questions.  Like I said, it surprised me they changed to 8V, especially if they're calling for 6V boards!  Without seeing the board in question, I have no idea what you have.  It could have easily failed partially open if it was cooked by excessive power, that's not unreasonable.  I've never seen an 8V regulator in one of these.  Clearly, that's what you appear to have, I have no idea what the 6V is also.

Some MTH operating reefers use the Seuthe style smoke cylinder.  On that design, the circuit board has a 7809 regulator.  The board outputs to the light bulb and the smoke unit turn on together are labeled 6V Out and 9V Out.  There's a power resistor between the two connector which drops the voltage from 9 to 6.  Additionally there's a switch in the wiring to the smoke unit to turn it off.

What's my point?  This can be a case where you can make a better mousetrap.  So rather than second guess if parts were installed incorrectly or whatever, why not get a new smoke unit and determine for yourself the best operating voltage.  Change the 50 cent regulator to a 7806, 7808, 7809, or whatever works best.  Add a 25 cent resistor between the 2 connectors so that the bulb and smoke unit get their best respective voltages.  Add a 25 cent switch to allow on/off.

The unit I took out of a modern WbB N&W J was an 8V unit.  The newer stuff has it.  So your unit is original.  These engines also come with instruction sheets and parts list.  Should be on it.  G

Yep, I have the instruction sheets that came with both the S2-103 and the S2-100.  Both sheets refer to replacing the headlight with a 6v bulb but say noting about the voltage of the smoke unit.  Interestingly, if you go to http://www.bachmanntrains.com site and read the current instructions for the S-2 Turbine  6-8-6 Locomotive http://www.bachmanntrains.com/...wgs/S-2_turbine.pdf, it now says 8 volt bulb.

Also, I find it interesting that Williams goes to great effort (in the instructions and on a special tag) to make sure the owner knows not to use the wrong smoke fluid or else the unit will plug or fail.  And yet there is not any warning about turning off the smoke unit if not using smoke fluid.  And if, as I believe, there is no switch to turn off the smoke unit, then the warning should be never run the engine at all unless there is fluid in the smoke unit.  But Williams doesn't seem worried about what would happen if the owner runs the engine without smoke fluid.

I don't know anything about this site http://www.trainweb.org/girr/t...ips3/smoke_tips.html but the author seems fairly knowledgeable about smoke units, and, referring to the Seuthe units, he says: "The 5 volt units will likely have less of a tendency to burn up simply because their input voltage is usually well controlled to produce an optimum power level of 1.5 watts. For example, the smoke unit in the Lehmann Porter cannot be turned off. It is a 5 volt unit and mine has many hundreds of operating hours with a dry smoke unit and it still works."

Based on all the information above it makes me think Williams did not feel there was any problem with running the engine without fluid.  So then I wonder what else besides running it dry might I have done to cause my unit fail?  If I don't know what the cause was, then if I replace the unit will it soon fail again?  I don't mind replacing a 50 cent item or even a $5 item, but the Seuthe replacement units that I can find are a lot more expensive than that.

You'll note that they mention a 5V unit and lower power dissipation.  I don't know how prone they are to cooking themselves as I don't routinely use anything with a Seuthe smoke unit.  They pretty quickly find their way to my parts box when I put in the fan driven replacement.

My understanding is that any heavier smoke fluid would have issues in Seuthe.  The LGB is a very thin/low viscosity fluid.  G

hello guys and gals, Gunrunner john or GGG or electronic experts.

I just bought a # 7 Seuthe smoke unit for the early Williams brass Hudson I been working on, check out the thread "looking for tips or advices for the early Williams Dreyfuss Hudson to run ".   I picked that model number as I thought that would be a the best running speed range (60 to 70 smph) for the smoke unit range but now not so sure as I realized that the motor voltage is limited up to 12 volts (Pittman motor) and the operating range for this smoke unit is 11-16 volts.    Is there some kind of the voltage resistor or something to limited the voltage to 12 volts on the motor but have to go higher in voltage like 14 volts to make the smoke unit operate nicely.    I do not want to switch to a fan driven smoke unit as the boiler front and shield is soldered .    When I got the engine from Don, the front shield has already fallen off due to poor soldering from the factory and I reattached it using JB weld so its not removable.   I will be posting more pictures of the work done this week soon (adding roller pick ups for tender, Williams true blast II sounds, more clear coat spraying on bodies prior to decaling etc.)  What can be done before I solder the wires ?   The Blackhawk Hudson is almost finish !

 Jesus spoken in red words   "So he called every one of his master's debtors to him , and said to the first, 'How much do you owe my master?' Luke 16:5 NKJV

Tiffany

What you really need is the 6V Seuthe smoke unit, then you can regulate the voltage down for the unit.  That's how most of them are used.  I have the smoke unit and the appropriate power module.  This is the combination with the throttle of the Z-1000 cracked enough to get  a voltage out, around 6V.  The voltage out remains constant over the range of track power from the switching supply module.

The switching power supply also allows for powering constant voltage 6V lights, LED markers, and a switch to turn smoke on/off so that the smoke can be independently controlled and the lights always on with track power.

gunrunnerjohn posted:

What you really need is the 6V Seuthe smoke unit, then you can regulate the voltage down for the unit.  That's how most of them are used.  I have the smoke unit and the appropriate power module.  This is the combination with the throttle of the Z-1000 cracked enough to get  a voltage out, around 6V.  The voltage out remains constant over the range of track power from the switching supply module.

The switching power supply also allows for powering constant voltage 6V lights, LED markers, and a switch to turn smoke on/off so that the smoke can be independently controlled and the lights always on with track power.

Hello Gunrunnerjohn

That looks like something I need for the Williams Hudson I been working on for almost 4 months now.

And He said to them, " Draw some out now, and take it to the master of the feast." And they took it. John 2:8 NKJV

Tiffany

I think Williams do themselves a dis-service still using these rotten smoke units. When they do work, they spit oil out over the loco and smoke pretty pathetically in any case. The best thing you can ever do with a Seuthe is run it dead or replace with a Lionel or MTH fan driven unit.

I certainly think they'd be better off doing a fan driven unit, it would be much more impressive.  However, I'm also sure that price figures into them using the Seuthe units.  The Seuthe smoke units are really not that cheap, so I'm not sure how much more expensive a fan driven smoke unit would be.