The data sheet is referring to the specifications for the entire 1.5KE TVS family. Your TVSs have a nominal voltage limit of 36 volts, which is a reasonable value for use with almost all toy-train transformers.
Bob Nelson
Thanks Bob, I looked at the TVS's I bought (1.5KE36CA) and the data sheet lists it from roughly 6 volts to 400 volts. Should I be looking for a 6 to 50 volt range? Your explanation of operation cleared it up for me! Thank you for taking the time to respond!
Best,
Joe
I don't know what you mean by "force a short". If you are expecting that it will create a short circuit when a voltage spike occurs, that's wrong. It just limits the voltage to a specified value, which should be chosen to be just a little greater than the peak voltage normally there. That is the square-root of two times the RMS voltage number. So, if your transformer puts out 18 volts, for example, the TVS should be chosen to limit at 18 * 1.414, or no less than about 25.5 volts. But 50 volts is not too high, since practically any electronics will withstand that. Without an oscilloscope and a way to generate voltage spikes, there's no easy way to test the things.
Across the wires to the track is good; but it doesn't really matter whether you put it across the transformer terminals or in the locomotive or anywhere in-between. If it is connected so that it would light up if it were a lamp, it's in the right place.
Bob, and everyone else that has responded to my posting....THANK YOU ALL!!!!!!!!!!
The one thing that keeps coming back to haunt me is the {TVS)!!! I understand the concept, and even bought a few, BUT, can someone PLEASE tell me WHERE to connect them to??????? I'm sure this sounds like a FOOLISH question, and I apologize for my ignorence, but I tried putting the TVS across the track current leads, and I could not "force" a short. Temporarily, I'm using a couple of #92 Lionel controler buttons, which have tripped immediately on any derailment.
Thank you!
It is overvoltage across the fragile electronics, not overcurrent around them, that causes the damage. A transient voltage suppressor (TVS) will provide better protection with any transformer than the fastest circuit breaker will; and they're dirt cheap.
I quess that the subway cars were ProtoSounds2 equipped. If that were the case, any old transformer does not break the circuit fast enough for the modern electronics. The solution there is an MTH Z-4000 or Dalee makes a power guard to rapidly terminate the power on the tracks.
I do PS2 upgrades and two of the most recent batch of Diesel upgrade kits were disasters. The most recent was shorted out form the start. MTH wil;l not make good on stuff like this unless you are an authorized repair facility.
I would not get a PS2 upgrade kit ($179) but use Dalee or another sound system that is not as suseptable to shorts.
Do not run PS2 locomotives with an old ZW.
bruce
MTH has a very poor parts setup. I was trying to find something as simple as light sockets for MTH passenger cars. Nothing is available.
It sure does not give me any desire to buy any more MTH products. Charging for something they cannot fix is another reason to stay away.
If I were you I would convert to an aftermarket setup.
I haven't had the need so far, but I understand Dallee Electronics (they advertise in CTT) has replacement boards for modern toy trains. You may want to contact them. I believe the Dallee boards won't have all the "gee whiz" features the original equipment boards have but they will get the trains operational again.
Good luck!
When I first got back into my O guage trains, about a year ago, I had purchased an MTH subway car train to run with the old Lionel's I've had since I was a kid (I'm 66 now!). Not being aware of the dangers of using my Lionel ZW transformer with the higher tech digital MTH, I derailed one too many times and apparently cooked the boards in the subway car (FYI, the subway car instructions said using the ZW was ok). I sent the boards (only) to MTH, they kept them for 2 months, charged me a servive fee, said they couldn't be repaired, sent them back to me, with NO option to buy new replacement boards. Now, I'm trying to at least find a "part number" for the boards, so I can at least attempt a search to locate replacements. BUT, they don't even make that easy!!! I was hoping someone reading this has some idea of where I can find part numbers for the MTH Subway car driver boards, or have been down this road and already have the part numbers, or better yet know where I can buy a pair of boards???
If you read this far..............THANK YOU!!!
Our community is FREE to join. To participate you must either login or register for an account.
Get the Classic Toy Trains newsletter delivered to your inbox twice a month