Aristo smoke unit mod ?

[Phil Stump]

Has any one tryed to defeat the safety shut off circut in the aristo smoke unit? I get so tired of having to stop my K-27 [and others] to re start the smoke. If this could be done it sure would make running trains a lot more fun. Would just have to be very careful not to run out of smoke fluid. Might be wise to install a shut off switch. If I knew any thing about electronics I would rather modify the system to work more reliably. It sure is a neet smoker when it is running.

[altterrain]

I guess the question is why would you want to defeat the circuitry that prevents the unit from over heating and starting on fire? 

-Brian

[Phil Stump]

my aim is obviosly not to set anything on fire but to stop unwarrented shut downs every 3 min.

[Superheater]

Phil,

Read this on George S page:

http://www.girr.org/girr/tips/tips3/smoke_tips.html#aristo

The problem is proabley not the shut off circut but the placement of the wick.  If it doesnt run out of fluid it wont shut off so fast.

John Fitch

[altterrain]

You might have gotten a bad one Phil. I remember reading about a problem with some over on the Aristo board. The two smoke units in my E-8 usually run about 20 minutes.

-Brian

[Phil Stump]

The one on my -9 has ran as long as 1hr when it was new. I have them in my k-27 , 2-8-0 ,2-6-0 , shay, 2-6-6-2,  They seem to really work fine untill they get a little age on them then all of a sudden every lap of the track they quit for no obvious reason.  I have no idea what is causing this and I do not have the expertize in electronics to run it down. I was hoping some one with similar interests had run accrost, or devised a cure. The people on the aristo board seem mostly interested in getting their units that fail replaced by aristo. I have not seen any one that sugested a possible cause or fix that could be done by the consumer in the field. The only thing I have seen any where is the opening up and making sure the wick is placed in the res. properly. I plan to fool around with a couple of them and see if I can come up with an answer that wont burn down the loco or the house.  Phil

[jimtyp]

I had a problem with mine.  I run track power and when my loco went over a dead spot the smoke unit stopped.  So I modified the smoke power pickup to come from the loco and the tender.  Yes, had to run an additional pair of wires, but since then it works all the time. 

Also, if you have DCC, I set up an output from the decoder to turn the power off to the smoke unit with a click of a button.  So if it did turn off I could easily turn it back on.  Recycling the power to the unit was the only way I could find to turn it back on.

[Phil Stump]

You are correct. Turn off the power , then turn it back 0n. problem is I run track power so that means stop and restart the train.  I played with one this past weekend. I totaly destroyed the pc board and hot wired the fan and heat element. Track power is way too much for it so I started with zero and ran it up to the best power setting I could find. 6 volts gave the best smoke but that is too much for the fan. So I think I will go to radio shack and get a 6 volt bridge rectifier  and a resister for the motor and see what happens.  Phil

[jimtyp]

Phil, which smoke unit are you referring to?  I was assuming the SD-45 unit with a fan?  The instructions that came with mine says it can take up to 24v direct.  So I did and mine works great.  I run DCC and have a constant 22v to the track, no problem.

[Phil Stump]

I dont know enought about dcc to comment. I do have some experence with aristo pwc and I know the smoke units work much better with it than with linier power. I do not want to run pwc for two reasons. [1] some of the guys in my club are of the opinion that pwc will damage their motors and I would not go against their wishes for any thing. [2] I have not had consistant luck running soundtrack sierra on pwc. [ lgb sound definitly dont like it.] And yes I am talking about the fan driven unit. I told you above what I am going to try with 1 unit , I have another one that I think I will leave the board on and try different things with, like pwc, mess with the wick, ect.  Phil

[Greg Elmassian]

The sd-45 type has an on-board regulator, so it can be fed higher input voltages. The regulator is actually a microprocessor, so it often resets if the input voltage goes too low.

The method of how/why the units shut off has not been determined (since it's code in a micro), but I surmise it tries to watch the current draw on the resistor that heats the wick and vaporizes the fluid.

It's thought that the aging of the resistor, changes in capillary action in the wick as it ages, and maybe some other things are the variables that cause a once nicely-functioning unit to not run well.

Replacing the wick/resistor assembly does not always solve the problem.

So Aristo customers just keep sending them back until they get ones that run well.

I have a friend that has 9 of them, and is slowly getting a few to work, and continually sending the non-functioning ones back.

Regards, Greg

[Phil Stump]

I do not have any good ideas as yet. I do however plan to keep trying. If I stumble acrost something that works ,or even helps ,I will let you all in on it.

[Greg Elmassian]

Phil, sorry if we were not helping in the right direction.

I will look to see if someone has measured the current through the resistor so you could make a regulator to set it....

The fan should be 12v, but, again, I will try to find out for you.

The Aristo site has a lot of threads on this smoke unit, so you might want to ask there...

Regards, Greg

[Phil Stump]

The Test I did  Found that 6 - 8 volts gives the best smoke.  That is too  much voltage for the fan. I plan on setting up the unit that I still have stock  and check the volts to the motor while it is running. I suspect it will be in the range of 2 - 3 volts. If that is true, I will need 2 regulators, mounted to a fair sized heat sink. This is all beginning to look like the long way around. The short way would seem to be, modify the original board. Back to square one. I wander if this all could be the reason the guys on the aristo board are simply sending them back. (such is life) 

[Bud Steinhoff]

I have installed the SD45 type smoke unit in just about all my locos.
Constant 22volt track power   straight to the smoke unit. (other than original Aristo locos)
All mine smoke for at least 20 minutes.
The problems that I had and fixed is making sure you have clean wicks that are tight on the coil and only use Aristo smoke fluid, others will clog the wick.
Many of them when they will not keep smoking is either caused by a break in power from track problems or not enough pickups or what I found is that the capacitor in the smoke unit swells from the fluid  and pulls the leads loose from the board.
I have cut the swelled rubber from the cap and resoldered them in or better yet replace with new caps and leave a gap from the board to allow for swelling.
After going through these fixes I have very little trouble with any of mine prematurely shutting down.
Bud