Tortoise problems-probably mine

[dadret]

For about a year I've had 17 Tortoise switch machines hooked up using DPDT toggle switches and a single 12V power supply - Option 1 on the Tortoise instruction sheet (DC with cross wired DPDT switches) and they have been working fine.  Now they have all quit working and the AC adapter becomes VERY hot and I think I blew one up (it quit working and was all bulged out on the side).  I recently redid all the DCC bus wires and probably knocked the Tortoise wiring around quite a bit which is likely the cause of the problem.  I was wondering if anyone had a suggestion as what I should start looking for or should I just start over?  I'm considering just replacing all the wiring and going to Option 2 (Bi-Polar DC with SPDT switches) which is maybe what I should have done in the first place.

[Vail and Southwestern RR]

Nothing wrong with the single supply method.  It sounds like a short, to me.  Somewhere along the way I think you have the output of the power supply shorted.

[Texas Zepher]

I was wondering if anyone had a suggestion as what I should start looking for

0. Cycle every single one to make certain there isn't one stuck in the opposite direction.

1. Get an ohm meter and test the tortoise "bus" to see if one of them has a short or near short.

2. Get and amp meter and test the current draw of all the tortoise together to see how much they are pulling.  Make certain that isn't exceeding the power supply.  Sounds like you are using self contained plug in supplies.    Then match the measured current with the amount of current they should be pulling - normal x number.   If it is over the "should be" amount, one of the tortoise is pulling too much power.

3. Hopefully you did not solder the leads directy to the tortoise and used the plugs.  Start unpluging them one by one until you find the culprit. 

The problem with the SPDT +/- 12V wiring system is if the turnout needs to be controlled from two different locations.  They it has to be treated like one would a household 2-way or 3-way switching system.

I have personally come to prefer the AC power method and using momentary contact switches. 

[baron9]

 I had the same problem only with 22 tortoise machines with spdp toggle switches. After a call to my local hobby store where I was told the same thing that there was a short somewhere and good luck in finding it. Then he gave me a suggestion to use NCE switch8 which will control 8 tortoise machines. All it takes is power directly from the track to the switch8 and then two wires to each switch machine then to the switch8. I do run DCC and control all my tortoise machines from my hand held throtle. Oh the cost of the switch8 was around $48.00 and well worth the price and the discount on the frustration.

[dadret]

I just looked up the specs on the NCE Switch 8 and it looks like a pretty slick system-I just need to find out if it will work with my MRC PA but I think it will.  I should be able to convert what I have now by just disconnecting all the wiring to toggle switches etc leaving just the two leads that I (unfortunately) have soldered to the Tortoise and then run those to the Switch 8.  Any problem with that?  Wish I had known about the Switch 8 a year ago (and also the card egge connectors).  I'll spend some time first trying to locate the short but thats not my favorite way to spend an afternoon (or several).

[dadret]

SOLVED THE PROBLEM!!!  Everytime I think I am becoming a DCC nerd I find something stupid I did.  I don't know how or when I did it but as I got to my second series of Tortoises and toggle switchs I found both the positive and negative sides on the bus wire connected together with the same wire nut - seperated them like they're supposed to be and everything started working just like its supposed to and the AC adapter is not about 200 degrees.  I still think I'll convert to the NCE Switch 8 but probably not for a while.

[Phoebe Vet]

I was about to tell you that it had to be a short, but I see you have discovered that for your self.

In the future, I would use fuses.  They are much cheaper to replace than transformers, and almost never catch fire. 

[Texas Zepher]

I still think I'll convert to the NCE Switch 8 but probably not for a while.

The disadvantage of that type of a system is that it uses expensive DCC power rather than cheap DC or AC.  With enough turnouts added to the system one will eventually need a DCC booster just for them.

[Texas Zepher]

Everytime I think I am becoming a DCC nerd I find something stupid I did. 

hehehehe actually that has nothing to do with DCC.  A short is a short - self inflicted or not.