DCC sound upgrade on largescale 55 ton shay

[piercedan1]

I had issues with this upgrade and finally figured out where I went wrong.  NMRA standard for large scale is 22 volts DCC, my system is 24 volts DCC.  Soundtraxx Tsuanmi decoder is 21 volts and they have error codes on their site.  I got 10 blinks which is over voltage.
I set my system to 18 volts and all is now OK.

I do wonder how users of 24 volt only systems get around this  (LGB MTS systems are not adjustable for one)

[armorsmith]

Dan,
I have used an LM317 or LM350 with great success in limiting voltage. I have an LM350 limiting the voltage to my Airwire controlled K27 to 16.5 volts and an LM315 dropping to 5 volts for the circulation fan for the electronics in the tender.

Both are from this web site http://www.learningaboutelectronics.com/Articles/LM317-resistor-and-voltage-calculator.php.

Happy Rails.....

[StanAmes]

Fortunately only the sound version of the 3 truck shay has this issue.  In mine I use rectifiers to lower the input voltage to a level tat the sound level likes.

Hope that helps

Stan

[Greg Elmassian]

You cannot use a DC regulator to lower DCC track voltage