Weaver smoke unit wiring question

Well, that's a TAS (Train America Studios) smoke unit, I can tell you that.

The smoke fan motor plugs into the 2-pin connector, don't know where it's connected for your picture.

Here's a shot of one with power and ground going to two of the terminals...

The center one I can confirm is ground.

gunrunnerjohn posted:

Well, that's a TAS (Train America Studios) smoke unit, I can tell you that.

The smoke fan motor plugs into the 2-pin connector, don't know where it's connected for your picture.

Here's a shot of one with power and ground going to two of the terminals...

The center one I can confirm is ground.

Thanks for the information.  It is indeed labeled "Train America Studios" and also "AC version".  So would the three prong connector be for the heating element?  And any idea what voltage these would use?

The smoke unit has on-board regulation, it takes track power.  I believe the one labeled C goes to track power as it goes to the full-wave bridge made up of the four diodes.  Your E goes to the triac that regulates the heater, so it may also connect to track power.  I'm sure that D is the ground.

I put this on the bench when I got them a long time ago, but I haven't had occasion to use any of them, so they're just living in my parts box.

Thanks GRJ.  I'll give it a try.  Ed

"What voltage is used" ? 5v-20v would be my guess

For the motor voltage, read the number off the chip with the heatsink and mind the last two digits as voltage output. I'm pretty sure that's the regulator. Looking the whole letter/number up would tell you for sure. Regulators of various chip brands usually use a common part number vs proprietary.

Reading the resistance of the element would give a clue if that could handle direct power input, bypassing the board regulation.

  But I "think" that I recall the TASs had a monitor circuit to reduce power if resistance rises (from heat) to avoid element burnout from running the unit dry. So I wouldn't bypass a TAS without investigation; I just thought it worth mention in the long run of things. Hopefully John will know how far off base, or safe I might be here.

The resistor is 10 ohms, and it certainly need regulation!  The motor is a 5V motor, and the regulator conveniently puts out 5VDC for the motor and the uP on the board.

There is a thermistor in the smoke chamber that cycles the heater on and off to maintain the heat.  Oddly, one of the ones I have had NO WICK, but still smoked pretty good.  The heater extended down farther than most smoke units, and I was surprised that it worked at all.

OK, I hooked one up and fired it up.  The left hand two terminals are power, not sure what the right hand terminal is for.  Oddly, I thought it would be power as it goes to a bridge rectifier arrangement on the board, so it must have a function. 

In operation it cycles the element on and off but the smoke output stays pretty constant.  These were from 3rd Rail diesels, so they don't have the chuff input.  Makes decent smoke, but not MTH smoke.  FWIW, this one does have smoke wick, I tried the one that didn't have any wick, and it worked, but when the heater went off, the smoke immediately dropped way off.  Obviously, they should have wick, I was amazed that when I got them, none of them had any wicks.  They were obviously used, so maybe someone took the wick out.

gunrunnerjohn posted:

The resistor is 10 ohms, and it certainly need regulation!  The motor is a 5V motor, and the regulator conveniently puts out 5VDC for the motor and the uP on the board.

There is a thermistor in the smoke chamber that cycles the heater on and off to maintain the heat.  Oddly, one of the ones I have had NO WICK, but still smoked pretty good.  The heater extended down farther than most smoke units, and I was surprised that it worked at all.

OK, I hooked one up and fired it up.  The left hand two terminals are power, not sure what the right hand terminal is for.  Oddly, I thought it would be power as it goes to a bridge rectifier arrangement on the board, so it must have a function. 

In operation it cycles the element on and off but the smoke output stays pretty constant.  These were from 3rd Rail diesels, so they don't have the chuff input.  Makes decent smoke, but not MTH smoke.  FWIW, this one does have smoke wick, I tried the one that didn't have any wick, and it worked, but when the heater went off, the smoke immediately dropped way off.  Obviously, they should have wick, I was amazed that when I got them, none of them had any wicks.  They were obviously used, so maybe someone took the wick out.

Got it!  I fired mine up the same way and it works as you say, just two wires to the three-pin connector.  That little motor sure runs fast at 5 volts!  Thanks so much for your help.  Ed

Great, enjoy.

Now that you've got this to work the below-referenced resources might be surplus to requirements but on the other hand it might not do any harm to add them to the knowledge base.

I remember several years back getting one of these TAS units for a 3rd Rail engine (their manuals rather confusingly refer to using TAS smoke units long after TAS ceased to exist). I didn't know enough about smoke units to make sense of the manual that came with it (attached) and the unit is question has resided in its box ever since.

I guess these units were fairly sophisticated for their time with the thermistor function, later used in Legacy smoke units, and they also had both chuff and "Diesel Accel" functions. Not so long ago someone queried using them in a 2 rail DCC engine and Mike R. weighed in on the wiring: https://ogrforum.ogaugerr.com/...a-studios-smoke-unit

The manual linked to that post explains that what was labelled the "AC" version of the unit could in fact come wired for DC. I vaguely remembered the manual but could not find it when I saw the present thread. Anyway, FWIW, its attached as I now see how the wiring explained above gets the unit to work for 3rail purposes.

   I never seen one in hand, but liked the thermo control idea allot as a saftey vs flow control. 

  I was just jumping back into the hobby and was searching for smoke unit alternatives; I couldn't even find a stock ni-chrome or Marx bearings yet; when I heard about TAS.   I'm thinking back and believe someone at a mfg forum was once using them in G without wicks, likely because of experience with old bathtub units; Ni chrome strung totally submerged in big Xs across the tub width like a fence or rope cradle   XXXX, with tension springs and standoffs/isolators, looking kinda like catenary tensionors.🤔 Tensioners ¿?

Seuth?¿

(Sueth!? Sleuth! 🕵️‍♂️ Whatever😲😂)

  I'm wondering if 10ohm would boil a whole tubs worth 😤 😈 🤓🤠 🤣 In G you might need that much to match your rep. tackling G,  John.

  Size alone made many look like poor smokers. An un-modded Lionel unit wasn't enough imo.. One of the roots of why I dropped G except for batt. op."toys" was poor smoke. (usually no smoke really)

  Funny, toys in general smoke great for what's there. The veggie oil/glycerin/ water mix lasts years without refill too.

In the case of the TAS smoke unit, I'm pretty sure it's really a flow control.  You can watch them cycle regularly, and all of the ones I have here do the same thing.

So, just to complete the story, the smoke unit has been added as an accessory to the layout.