What the heck is a "Semi Smart" smoke unit??

The semi smart design is a basic smoke unit but lionel used an ACREG a small regulator that can be controlled by the R2LC or R4LC for early Legacy to turn smoke on or off, but also give you 3 smoke levels.  L, M, H using the momentum buttons on a CAB-1, or 2.

 

So the mods are the same, but you use the 8 ohm resistor, because this is powered by the ACREG not track power.

 

So semi smart is the term Lionel gave,  G

Wow.  Not sure why I would want to vary smoke output like that but nice to know.  

 

Lionel could have selected a better name, I think: in my line of work (power systems), "semi-smart" usually means "not smart enough."

Does this only apply to Legacy.
My NYC Mogul uses a "semi-smart" unit.
Is the smoke adjustable?
Or is it in the " not living up to ones potential" category.

Then Lionel picked the right name. These things are not smart enough to keep out of trouble and and always getting knocked out. They have become a revenue stream for Lionel and their service stations.

 

Pete

The semi-smart smoke unit also controlled the smoke fan for chuffing, too bad they didn't also run it slow at idle, a significant oversight.

 

Pete, the part that dies a lot is the smoke regulator, I have a little pile of bad ones, they seem to die at a pretty good clip.

 

Thanks for the replies...

so if I understand it could be the resistor is OK but this ac-reg thingie could be the culprit.. how do I tell??

Unplug the smoke unit, measure the resistance of the resistor.  It'll be in the 6-7 ohm range if it's good.  I think at least 9 out of 10 failures there end up being the regulator module.

 

Hey.....that is what my 3rd grade teacher wrote on my report card!!!!!!

 

JohnB

A "semi-smart" smoke unit? Must be something like a "semi-scale" train.

 

I always got a  kick out of that silly term. Semi-scale...sort of like being almost pregnant. Every model is built to SOME scale of the real thing...except those that are built to a "semi-scale" - whatever that is. 

Rich, some of the compressed models that are not to any scale may quality as semi-scale.

 

I'm pretty sure that relates to capital hill: They think they're smart and they're always blowing smoke up our butts :[]

Really, do you like your trains speed on or off?

 

Some folks like small amount of smoke some like large amounts.  This was the first method Lionel attempted to meet the capability MTH had built into their system.  G

Semi smart tended to be in the upscale models.  TMCC and early legacy.  If your instruction manual discusses changing smoke output you have an ACREG.

 

I don't think the ACREG puffs the fan John, the semi smart still had a pin to ground the fan motor via a chuff switch.  That is how most are operated.  Fan is only on when switch closes for chuff.

 

No electronics on top of the semi smart and there is no fan output on the ACREG.  The "smart units" which have chips on the smoke unit, can control fan output.

 

If you go to Lionel's parts page under smoke units, you can see the variety of units.  Too many in my mind.  G

 

SEMI SMART SMOKE UNIT / 23 OHM / SCALE MIKADO

 

 

 

Lionel may have let there terminology change, but I thought what you show is the smart smoke, vice semi.  Notice that one uses the 23 ohm so no ACREG.  Has all the chips on the PCB.

 

I posted some info on the Command thread with a diagram.

 

Semi smart at least in it's first version had no chips on the board and used the ACREG for control.  Below is the same PCB unit earlier rev and they call it Smart Smoke.  So maybe the Parts guys aren't consistent with the terminology.  G

 

 

 

 

 

I was going by what Lionel called them.  They have so many different smoke units, it's really hard to keep track.

 

I have one of those you picture in my parts box, it seems dumber than the one I posted, so their terminology is really out to lunch.

 

G actually nailed it in his first post. The "smart" part of semi smart is in the AC reg. The fan unit is dumb.

 

Pete

I have the "super-smart" option, the Super-Chuffer.   I let the semi-smart AC regulator handle the resistor.

The AC REG must be a product of todays education system. Back in the day it would have never graduated from grade school.

 

Pete

Gunrunnerjohn&GGG- I'm really confused (to say the least) I have #844 #6-11116 with a coput "ANALOG smoke unit-which is stone cold! ACREG????

SSMU

Simple SMoke Unit - is the Engineering naming convention, and it has many variations.

Used with AC-Reg(ulator) for a complete solution.  As folks indicated the "smarts" are in the AC-REG.

Thanks Jon, I wondered what the SSMU really meant!

 

Dumb question, why the labels of smart, semi-smart, etc.?  Is that just how a parts guy somewhere named them?

 

The names come from internal discussions and code names on the projects.  It just carries over to folks and sticks.  Don't read too much into the names bantered about.

 

The real important part is the -F or -K suffix.  That is what defines the operational requirements on the SSMU. 

 

Another example, the latest smoke unit, the OGSU (O Gauge Smoke Unit) comes with a 8 ohm, a 16ohm, and/or a temp sensor, etc.  The suffix defines the model.

 

 

Thanks, that explains a lot.  There do seem to be a lot of flavors.

 

The blackened resistor and burn marks on the board don't always require a new board. Running them dry for long periods of time will do the same thing. I repaired 2 of my TMCC engines that were dead just by the looks of them so I thought. All they needed was a new resistor.

Thanks Jon (SantaFeFan), your contributions are always welcome and appreciated here.

The Lionel Parts page is really a good resource for helping you.  Yes you have the analog with 6ohm resistor.  So it also has the ACREG.  This is part #1 on lionels page for your engine.  691ACRG103.

 

It the smoke unit resistor measures 6 ohms and the wiring is good you can check for fan rotation.  If not fan rotation check for 5V.  IF you have 5V at the fan, the issue can be a bad fan motor.  If no 5V you trace the wires back to make sure good continuity to the switch, wiring etc...  If all good, change the ACREG.   G

I've only replaced two Lionel smoke unit PCB's.  Both were the result of the ACREG failure that puts prodigious current and heat into the 6 ohm resistor, it really makes a mess of the board.  Other than that, you're not likely to have to replace them.

 

Apparently the "Simple" is a misnomer?   Could have been the CMU.  G

No George, a CSMU.

 

Well we could always go with:

Smart SMoke Unit 

Thanks ALL for explanation Here on Arizona smoke unit repair (or any repair is quite $$$) No LSU's,everything go's back east engine weight =shpg rape!

I thought this one was cooked for sure:

 

 

Rebuilt it with a new resistor, new batting, dumped the sleeve, drilled out the intake hole and cleaned it up. It smokes as good as my Legacy engines now. So now I have a couple extra PCBs that I didn't need.....yet

Not even close, the ones I've replaced have had the fiberglass charred almost totally through!   Some solvent on that one and a little scrub, and it would probably look almost new.

 

I have that engine too. Started smelling tell-tale burnt plastic smell and then the smoke stopped. I actually had a spare smoke unit board for this model so I replaced that. However, although the fan would spin there was no heat from the resistor although it was brand new with the board. Sent Mike R. a message and he diagnosed ACREG failure. He told me which wires connect to it, I installed a new one and that did the trick. 

 

 

The "semi smart" tag came from Lionels long list of smoke units. I looked up 6-38094 & 6-38095 the Hiawatha #3 and N&W "J" #611 and these are both equipped with the so called semi smart unit.. both have quit smoking and I guess I need to replace this AC-REG...

I have a question...where is it and what does it look like??

The AC regulator is either floating around in a small heat-shrink ball or later ones have the triac bolted to the frame sticking out of the small heat-shrink ball. 

 

Here's one with the triac exposed, that bolts to the frame as a heatsink.

 

Usually near the smoke unit, but don't discount a R2LC reset and using the codes in your manual to increase smoke to high.  Also the chuff switch, just in case it is a model that turns the fan on.

 

Those models have fan off for 90% of wheel rotation and only on for the chuff.   G