TVS diode suppressors

Thought to post this question hoping someone with experience here can answer. I am going to install TVS suppressors at my transformers and a friend asked if you could install them across your middle and outside rails instead. I didnt think so, but hope any assistance with this could be had from the more experienced on this forum. Thank You


Original Post

Joe---something you might want to take a look at.

I distribute railpower from transformer to rails via plate-jumpered Terminal Strips and mount a TVS on each strip.  The photo below shows an example of a 6 position strip with the HOT (green) and Common(white) conductors* from an 180 watt Powerhouse connected and energizing six screws. Thus, 5 pairs of Hot and Common scew heads are available to connect for soldering wire runs to the rails at diverse points on a single power district.

I also mount TVS at the 12 position Layout Distribution Strip at the Power Center that organizes and distributes to the various power district T-strips. 




* I remove all plugs from my PowerHouse transformer output conductors and solder on spade lug to accommodate virtually all threaded  connecting points on transformers, TIUs etc.

A&Y RY[NC's Southern/N&W connector].


Photos (2)

For our trains we recommend two models of TVS:

For power supplies in excess of 18VAC use the 1.5KE36Ca diodes.

If you only use supplies that are limited to 18 VAC then you could get by with 1.5KE33Ca diodes.


They can be found on Mouser, DigiKey and similar electronics providers as well as the 'bay.

Guitarmike posted:

They are pretty cheap, I wonder if it makes sense to put a few of them online?

If a TVS fails, it can fail shorted or open. If it fails shorted, you will know it right away if you have a good breaker! If it fails open, you will not know about it, and you will have no protection. So having several do make sense, because if one fails open, the others are still protecting.

If you are installing them in an engine, then I would recommend two in each engine for the same reason. You will have a backup TVS in case one fails, with the added bonus that your protection travels with you if you take any of your engines to a friend's house for a play date! Also, I like the idea of protection right on each engine because that puts the protection as close as possible to the place where it's needed, in this case the sensitive and expensive boards in your engine. I can't prove that there's an electrical benefit to installing them in an engine vs, at the transformer, cuz like Rob said, they are "electrically equivalent", but my gut tells me that it's better.


Add Reply

Likes (1)
Alan Mancus

OGR Publishing, Inc. PO Box 218, Hilliard, OH 43026 330-757-3020