I have an older S-2, the Atlas 8700series model, and was thrilled to see the articles about adding sound. I have Don Janes article and put my Micro-Tsunami in the same way.
Ran for awhile and then I started getting stall and 9 flashes (overheating). Finally got so it overheated even with cab off. Sent back to SoundTraxx where the board was rebuilt but was warned about higher than 3/4A stall current.
Have not been able to check my motor yet but Atlas says the stall current on those models is 1A.
Thus I am wondering how folks like Don Janes and Andy Sperandeo have gotten theirs to run OK? Just luck on the individual motors?
Jamie at SoundTraxx told me that they have had some other S-2s fail, so I am just wondering if there is another answer?
I have read, and experienced in one case, that Micro Tsunamis like to overheat if a heat sink isn't used with the decoder. I have two units with these decoders, same chassis, motor everything. One has a small piece of aluminum as a heat sink, the other does not. Guess which one I'm having overheating/shut down issues with?
I need to correct the problem by adding a heat sink, but haven't had an opportunity yet.
I'm not saying that is the problem, just my experience.
"The true sign of intelligence is not knowledge but imagination."-Albert Einstein
http://gearedsteam.blogspot.com/
This issue with the Micro was discussed a lot quite a few months ago in the Yahoo SoundTraxx Group. Many strapped the Micro using a couple small nylon locking ties to a piece of aluminum. A layer of Radio Shack heat sink paste between the decoder and aluminum plate. The bottom of the decoder is easy to figure out. Do not cut open the shrink.
There is more info in the below link. Take a little time to look around. You will find info about over heating.
http://www.mrdccu.com/
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
One amp is pushing the envelope a lot. I have had a loco with 650 ma motor current. including two LED's overheat the 750.
SInce when free-runnign the motor isnt likely to draw anywhere near 1 amp, I suspect the whole thing is poor heat sinking and a somewhat overoptimistic rating on the Micro-Tsunami. Getting the heat out is the key.
-_Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
I have to agree with Randy on overoptimistic rating.
I say that because I have two Bachmann HO 44 ton, single motor, each with a LokSound Micro that is rated at 500 ma and my 44 tonners measured, 650 ma with drivers running free. With the LokSound's, I run the locos at 20 mph max and not for very long. About the max prototype speed. Normally, 19 to 15 mph.
I sometimes wonder if some are running the ST Micro too fast.
I have opened a 750 and there is a thin heat sink on. The thin white is a piece of double sided tape. The IC's, chips. lay on the tape.
There is a good solution to reducing the potential for overheating the Micro-Tsu that many of us narrowgaugers use. Turn the output voltage of your DCC system down.
Mine is NCE, which was 14.5 volts at the factory setting. I turned it down to 12.5 volts and have never had a problem. I have 3 Blackstone C-19s and a Westside C-25 with Micro-Tsunamis.
The only drawback is if you have a lot of bulbs installed that you've adjusted their brightness with resistors, as they may become dimmer than you'd like. This is less of an issue with LEDs. Not a big deal in my experience.
Mike Lehman
Urbana, IL
If you aren't worried about the warranty, you cna do what Rich did and then actually proceed to fix it - double sided tape, even if it is some sort of heat sink tape, is a very poor heat transfer mechanism. There are specially made thermal glues and heat sink compunds that do a much better job of heat transfer. The thermal coumpund is better, but requires pressure between the chi and the heat sink - in a computer there are springs tightly holding the heat sink to the CPU. The glues are still better than tape though. If there is any space, a thicker piece of metal will dissipate more heat than the same size thin piece. use ordinary double sided tape to then attach the heat sink to the loco - you don;t want the metal in direct contact with the chassis in this loco. Fit the biggest piece of metal you can in the sapce available without it interfereing with anything, this should help keep the chip cool and maybe not shut down.
It looks to me that if the sink is taped on, it opens the door to enough production variation that some may not be as securely attached as others, also it appears flexing the wires toward the heat sink can slightly pry it away fromt he chips. This could be why some work with no problem and others have overheating.
--Randy
Lowering the voltage of the DCC system is a trick I remember now.
The double sided tape is made to transfer heat according to a couple reports I have read. Apparently not as well as SoundTraxx would like. To be fair, no idea on what users are really doing who have this shutdown issue.
All the added heat sinks I have read about strapped the aluminum right to the bottom of the shrink with a layer of heat sink paste on the flat side of the decoder. They did not remove the shrink. These decoders are not cheap.
I removed the shrink to solve some questions in a couple DCC groups.
Good solution is to look at the Yahoo SoundTraxx Group and maybe join the Group to ask a question. You can read the messages even if you do not join. You have to search the Group.
Thanks to all and especially Rich for taking the time to reply and explain.
I have more info. I was able to take the S2 loco to LHS and do a stall current test, got 0.61A...... sooooo
The problem is not my loco but the Micro. I now have the new/rebuilt TSU750 which is under warranty so I am going to re-wire and run it.
I am reading that others have used either brass or aluminum. I cut up a coke can and used a doubled piece under the flat side of the heat shrink. But I think the decoder was fried before that. I am going to do that again unless others have a better idea.
I am also going to call Jamie back and complain about SoundTraxx heat dissipation issues. I think they need to do better! I will find out what their policy might be if one cuts their heat shrink to allow better contact.
BTW, She mentioned that they had tried an AT1000 in an S2 and it JUST fit. Anyone try that yet? The width is dead on tight!
Stay tuned!
SoundTraxx is very aware of the heat issue.
Below is a link to the Yahoo SoundTraxx Group 750 discussion you can read without joining.
http://groups.yahoo.com/group/soundtraxx/msearch?query=750+heat&submit=Search&charset=UTF-8
I had a 750 in a Bowser HO scale VO-1000 that would shutdown on me. One LED and 650 ma motor current. Sometimes I was to quick on the direction change and the 750 would overheat. I would forget, I am playing with trains.\
Anyway, I switched to a TSU-1000.
Rich - think you can fit a AT1000 into an Atlas S-2? SoundTraxx has offered to exchange for me.
No idea on what you have for space for the decoder and capacitor.
I removed the PC board from my VO-1000, shortened the wires and hard wired the decoder. I managed to stuff the cap in also. I used a 16mm x 35mm speaker firring down over the front truck. The shell is the baffle and I am happy with the sound results.
I managed to squeeze a TSU AT1000 and cap into a second VO-1000. I will add, modified the frame some for the speaker.
Again, no idea on what you have for room.
With stuff like this, I get my caliper out and do a lot of measuring and fitting.
Yeah the caliper shows it is an EXACT fit to the 0.1mm , so I am not sure I want to risk it.
If the frame is the issue, grind some away with a Dremel and router bit. I have done that.
No, unfortunately it is the plastic cab that is an exact fit and I do not think there is any free edge on the AT1000 that can be trimmed down. I might be able to set it in on edge, but am not sure of the height?
Next day now and I wired up the "new" TSU750 and added a tin heat sink. Left it out of the cab and ran the motor for maybe 10 minutes before I got the 9 flash code and the decoder was very warm.
Sooooooooo, I am sending it back to Soundtraxx and going to try an AT-1000 in that cab.
Take a look at this. http://www.mrdccu.com/install/hods/Atlas-S2-826004.htm
Woodone - thanks for sending that link. But I have read that and have followed those directions exactly, it is just that my particular S-2 will not support the Micro. I have tried and as I said, it overheats in 10 minutes, even without the cab in place.
WOW! Are you sure you are not getting some wires pressed to one of the flywheels?
I did this install more that once and did not have any problems.
The brass heat sink has to be epoxyed to the frame. Did you solder the two small pieces of brass to the main brass heat sink?
Yes, in fact with this re-done Micro, I only wired it long with a thick tin heat sink added and left it on the table next to the loco to test. That decoder got hot to the touch within 10 minutes. Guess my motor is out of specs with others although it only tested 0.61A stall current.
Oh well.
"Hot to the touch" is one thing, but did it shut down?
I am really surprised that even works. I like Bruce and all, but bathtub caulk is certainly not a heat sink grease and I can't imagine it actually conducting heat from the decoder into the brass sheet.
Yes, the tape used inside the decoder is a heat conducting tape, but of the three ways to attach heat sinks to components, it is the worst of the three when it comes to thermal conductivity.
I suspect the issue is really just one of manufacturing tolerances. You might try something simple, such as genetly squeezing the decoder to seat the internal tape and heat sink better. Or has been suggested, try a Loksound Micro, which doesn't have this problem. Or even have heat sinks.
Use Radio Shack thermal heat sink compound. Tie the decoder to the metal plate with a nylon locking tie is what some have done for this thermal issue. Some how keep the decoder firmly against metal. This issue was discussed quite a lot in the SoundTraxx Group.
Do not use epoxy or bath caulk or any kind of glue.
Oh yes! I get the proverbial 9 flashes in the first 10 minutes of run. So I have sent it back to SoundTraxx and we are going to try the AT1000 fit.
Randy may be on to something as the decoder was hot but the tin heat sink that I had attached was not even warm. Oh well, I am tired of doing that wiring. Probably just a variation in Atlas motors.
I realize it's a small decoder, but .6 amp stall current is pretty low. Freely moving without the wheels stalled, it should be drawing far less than that. Even some of the teeny tiny Z scale decoders can handle a full amp.