Large Scale Central

"Keep alive" for Tsunami decoders

Electronics DCC
#1

Well, I have the Bachmann motor and sound decoder for the Thomas family.

It looks very similar to the Tsunami LS decoder (and it is clearly made by Soundtraxx)

It’s in an Emily which has lousy power pickup, and on this decoder, if there is a temporary power interruption, the loco stops, and you have to throttle down to 0 to get it to run again, even when power is restored.

Side by side pictures show where the Soundtraxx “current keeper” connects to the Tsunami, and it appears to be just after the 4 diodes that rectify track power, but I cannot be sure.

Has anyone experience with the Tsunami itself? Also would like to know if the “current keeper” is a cap bank and a resistor, or also has the diode.

Also, looks like I will have to use more caps, since I need to make this work on 24 volts… but the LS one uses the same current keeper…

Greg

#2

Hi there,

First post on this site, very interested in electronics for large scale.

I must say that I don’t think these are very similar, or that it’s clear that Soundtraxx made that Bachmann decoder. The pcb’s are quite different, as are the pads for I/O. They seem to share several components, but that’s to be expected. Designs from various makers inevitably share design characteristics and components. They may even be derived from the same open source designs.

That said, you might be able to reverse-engineer the Tsunami to figure out where to put the current keeper on yours. I’m interested in what you find out.

#3

Sorry, you are wrong, already a known fact.

And the Tsunami is not an open source design if you had researched the history of the product.

And this is not the first oem decoder SoundTraxx has made for Bachmann.

I had hoped to avoid purchasing the regular one to reverse engineer, that’s why I asked, because I do not like SoundTraxx decoders, they often have issues at G scale DCC voltages

#4

I am working on a Bachmann Thomas and it is definitely a soundtraxx DCC board. Matter of fact is only one board is available for all the Thomas engines and the sounds are selected by a cv for specific engines and the default decoder is always set to Thomas!!

Bachmann 44958 is the part number of the board and manual does state SoundtraXX AND TSUNAMI.

Go here and download the manual.

https://shop.bachmanntrains.com/index.php?main_page=product_info&products_id=6473

#5

Dan Pierce said:

I am working on a Bachmann Thomas and it is definitely a soundtraxx DCC board. Matter of fact is only one board is available for all the Thomas engines and the sounds are selected by a cv for specific engines and the default decoder is always set to Thomas!!

Bachmann 44958 is the part number of the board and manual does state SoundtraXX AND TSUNAMI.

Go here and download the manual.

https://shop.bachmanntrains.com/index.php?main_page=product_info&products_id=6473

Thanks, Dan for the link to the manual. I see it’s a Soundtraxx decoder.

#6

Greg Elmassian said:

Sorry, you are wrong, already a known fact.

And the Tsunami is not an open source design if you had researched the history of the product.

And this is not the first oem decoder SoundTraxx has made for Bachmann.

I had hoped to avoid purchasing the regular one to reverse engineer, that’s why I asked, because I do not like SoundTraxx decoders, they often have issues at G scale DCC voltages

I didn’t say they were an open source design, I said they may have both been derived from one; but just speculation. On appearances I wouldn’t have assumed they were both Soundtraxx, but I now know they are.

Here’s an excellent resource for connecting a keep alive to a variety of encoders, including some Tsunamis.

Stay Alive for Decoders

#7

Thanks, Marcus Ammann’s site is required reading for DCC people in my opinion.

You should also find Mark Gurries’ site and Mark Schutzer’s, especially if you have an NCE system, have used several of his mods for my NCE hammerhead throttles.

(you could also check our my site on DCC subjects (https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-wink.gif))

Back to Marcus:

You will note that most of his stuff is related to HO scale, so you have to use higher voltage keepalive components or you will have small explosions as the 16 volt electrolytics blow up.

You will also notice the references to issues with keepalives and CV programming. You might research what Zimo has to say about this, you will see a better solution than just the caps and resistors, and the on/off trigger. (Hint: inductor to isolate effect of keepalive on programming signals)

Glad you found Marcus’ site, I encourage you to keep going and read the other 2 sites.

Greg

#8

John Visser said:

Hi there,

First post on this site, very interested in electronics for large scale.

I must say that I don’t think these are very similar, or that it’s clear that Soundtraxx made that Bachmann decoder. The pcb’s are quite different, as are the pads for I/O. They seem to share several components, but that’s to be expected. Designs from various makers inevitably share design characteristics and components. They may even be derived from the same open source designs.

That said, you might be able to reverse-engineer the Tsunami to figure out where to put the current keeper on yours. I’m interested in what you find out.

Sorry, probably should have welcomed you on you’re first post!