I'd heard rumors that since the Atlas Commander DCC system uses 18 volts, it can burn out decoders after a while. Is this true? I personally haven't had any issues, but I haven't run my trains nearly as long as most modelers.
The Atlas Commander is an older DCC system. I believe they were manufactured by Lenz.
Is the 18 volts switchable to a lower voltage? Many DCC systems have a switch (or a software-controlled setting) to allow you to use either 18 volts or 14 volts (I think) to the track. The 18-volt setting is intended for large-gauge, like O or G, while the lower voltage should be used for HO or N.
It takes an iron man to play with a toy iron horse.
Here is a snippet from the NMRA standard:
The RMS value of NMRA digital signal, measured at the track, shall not exceed by more than 2 volts the voltage specified in standard S9 for the applicable scale. In no case should the peak amplitude of the command control signal exceed +/- 22 volts. The minimum peak value of the NMRA digital signal needed to provide power to the decoder shall be +/-7 volts measured at the track. Digital Decoders intended for "N" and smaller scales shall be designed to withstand a DC voltage of at least 24 volts as measured at the track. Digital Decoders intended for scales larger than "N" shall be designed to withstand a DC voltage of at least 27 volts as measured at the track.
Link to the standard: http://www.nmra.org/standards/DCC/standards_rps/S-91-2004-07.pdf
To me, it says the decoder is supposed to be able to handle it. I can't say what happens in real life.
Jeff But it's a dry heat!
I really love hearing some of these stupid, unfounded rumors about DCC.
In my nearly 20 years involvement with DCC, I've never heard of an Atlas Commander burning out decoders. The Commander is a watered-down Lenz system. Bernd Lenz of Giessen, Germany, developed what is now known as the NMRA DCC Standards and donated the technology to the NMRA.
And no, the output voltage of the Atlas Commander is not adjustable. It is spot on the NMRA Standard. Some lower quality decoders may burn up on it, but if so they would probably have burned up on any other DCC system.
What I've read is that some MRC decoders can't handle voltages well within the standard. In fact, they can't handle voltages from an MRC system. They sell a cludged up pile of diodes to drop the voltage.
This is hardly unfounded rumor.
http://www.tonystrains.com/technews/soundtraxx_heats.htm
--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've been using the Atlas Commander ever since it was first brought out. I did add a couple of bridge rectifiers to the out put not long after I got it bringing the track voltage down to about 14.5 volts. Have never had any adverse effects in all the years I've had it running.
Mark.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
Hmm. Looks like I'd better buy some diodes. That's kinda of annoying, but what're ya gonna do.
EDIT: I emailed Atlas about this, to see what they have to say. Might as well go straight to the source, before I send money to Digikey! :)
The thing is, it's a decoder issue, and not a command station issue. The command station is compliant. So the supplier of the command station isn't really the one to ask.I think Tony's document gave the best expalanation of things, even if everything is compliant, in some cases the installation may not be able to disappate the heat. So it can't hurt to reduce the voltage a bit. If the decoders themselves burn out, it's more of a decoder issue, but again, if reducing the voltage saves them, why not?
The post on Tony's indicates that Atlas resolved the issue in 2002. Even if the output voltage is an issue with SoundTraxx, the diode circuit seems simple enough. I would add that since the standard calls for track voltages above 20v, that a properly designed decoder would be capable of handling that voltage long term without damage.
Co-owner of the proposed CT River Valley RR (HO scale) http://home.comcast.net/~docinct/CTRiverValleyRR/