I recently purchased a Zephyr Digitrax. just before Christmas. Then a few days later when I was reconnecting the transformer to the Digitrax unit it started to smoke. Yep, you could smell the wires melting. So I wrapped it up and returned it to Digitrax. They were very nice about it and even though it was their busy season I had it back within less than 3 weeks. So far it works good. It is the same unit not a replacement. Some diodes were replaced from what I could decipher.
I did notice that they had made a change on the box of the transformer. They wrote in red ink 17 VAC where it had said 15 VAC. I tested it and it sure puts out 17 VAC.
Has anyone else had this problem? I’m just curious why they changed the output value to 17 VAC. I wonder if that had anything to do with the short in my unit?
I very much doubt that Digitrax actually manufactures the power supply/transformer, they are almost certainly manufactured and labelled for Digitrax by any of a huge number of supply makers in the world. My Zephyr supply is 3 or 4 years old and says “Made in Taiwan” on it. It is quite possible that these supplies are not made to precise tolerance or that they have had a bad batch. I suspect that the repair tech that worked on your system measured the output of the transformer to see if it was the cause of your smoke. Very likely this would be part of a standard procedure. Having documented the exact output they wrote it on the box. I don’t imagine for one moment that they modified the supply as part of the repair to increase the output.
Well now I will have to check mine when I get home. My box said 15VAC. Given that the output of the Zephyr is around 12 volts, adding more voltage to the input side is only going to make things run hotter.
The other thing to remember is that the voltage of the output DCC signal is not dependent on the input voltage from the powersupply. Even though the input to my Lenz is 18V the output to the track is only 14.5V. With the Lenz this is user configurable either with jumpers or software. I haven’t checked my Zephyr manual but I am certain Digitrax will be similar.
The Zephyr has a fixed output of about 12.5 volts. Other Digitrax systems have a 3 position switch to deliver 12, 14.5, or 18 volts out. The higher the input voltae,t he more te system has to dissipate, mostly as heat.
So far I haven’t had much time to use it a lot so I’m hoping it’ll be OK. I’ll let the forum know if any problems crop up. No, there was no explanation other than a small line on the work sheet saying about replacing some diodes. That was it.