I have one Tortise that keeps shorting my DCC system when it is thrown to one position. I am using contacts 2,3 and 4 on the PC contact board on the Tortise. contact 3 going to the frog on the turnout and contacts 2 and 4 going to the track/buss. I tried reversing the track wires and it makes no difference. I am wondering if the internal switch in the Tortise is bad. I have 20 plus more and they all work fine. I just thought of using contacts 5,6 and 7 as I am writing this but don't know if that would work. Any suggestions? I disconnected the frog wiring to keep the layout running in the meantime.
-Bob
Life is what happens while you are making other plans!
Bob,
The contacts in the Tortoise are not 'breaking' correctly - they may be 'tacked' on one side' I had one that would not switch correctly and it was a problem in the internal contacts. They pop open easy and you should be able to see the problem and fix it.
Jim
Modeling BNSF and Milwaukee Road in SW Wisconsin
Is this by chance a Walthers/SHinohara turnout? Or one of the others that happens to tie the frog and both point rails together? What's probbaly happenign, if it is, is that the points are contacting the opposite stock rail before the Tortoise has moved far enough to swap the contacts.There is a method to modify the Tortoise to increase the dead space betweent he contact points, but this voids the Tortoise warranty. Or the turnout can be made "DCC Friendly" which will also eliminate the problem.
This sort of short even happens with this type of turnout on DC.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Since you described the way you have things wired, the answer may be found in this wiring diagram:
http://www.trainboard.com/railimages/data/500/Scan10346.JPG
We are used to toggles, where the center post is usually the one that gets switched between the other two. This is not the case with a Tortoise. The frogs should be connected to pins 4 or 5.
It takes an iron man to play with a toy iron horse.
Some switches "make-before-break" and other switches "break-before-make" The latter is what you want, but if the wipers on the switch are too wide it will not work. I had that problem with Atlas relays, because I use them backwards. That is I put (+12vdc) on one side and (-12vdc) on the other, and expected the movement of the switch to select the polarity of the output due to its activation. This did not work because of the way the internal wipers worked. All I ever got out of it was a short circuit.
You appear to be using the tortoise the same way, letting it select which rail should power the frog. First make sure that it is not a problem in the turnout itself. After that bench test the tortoise contacts to see what they are doing. It may be that you will have to use a separate relay to power the frog. A rectifier in series with the relay coil will activate the relay in unison with the turnout.
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
Thanks for all the input. The turnout is a Walthers/Shinohara and it is DCC friendly (as are all my turnouts; DCC friendly that is!). MisterBeasley's diagram would explain the problem BUT, I have all my other Tortise machines wired as I described in my original post. I will try to rewire as per his diagram (and I am assuming it is from the Tortise instruction sheet). I may not get to this for a couple of days with Mother's Day and all the company I am having, but I will report my findings back as soon as I can. This happens to be one of two Tortise's that I soldered directly to the PC contacts, all my others have the slip-on edge connectors which I wire at the workbench, a much better way. If the rewire doesn't work I will use the other set of switch contacts (5,6 & 7) and see if that works. My last resort will be to open the Tortise and see what is going on in there. Interesting, I didn't know you could open them; I always thought they were glued together.
Thanks again,
Dunno how any of them actually are working properly , Mr Beasley's diagram is the right one, pins 4 and 5 are the commons for the two contact sets, and one of those should go to the frog. 2 and 3 or 6 and 7 should go to the rails.
Well, I do kind of know how it works wired as you describe - in one position, the frog is connected to one rail. In the other position - the frog is unpowered! The same thing I described with the Shinohara turnout will happen, even mis-wired. I suspect the short only happens when going in one direction, say normal to diverging, but not when going back. That would make sense per the way you have them wired.
Randy,
You are probably correct in your analysis; now that I think about it, the turnout in question only shorted out on the divergent position and that would all make sense now. I hope to get some time this weekend to fix this. Will keep you all posted.
farrellaa My last resort will be to open the Tortise and see what is going on in there. Interesting, I didn't know you could open them; I always thought they were glued together.
My last resort will be to open the Tortise and see what is going on in there. Interesting, I didn't know you could open them; I always thought they were glued together.
I recently opened a Tortoise to remove ballast which was fouling the gears.
I did this after a telephone conversation with Steve at Circuitron who told me to open the Tortoise, and he assured me that it would not violate the warranty even though the warranty says differently.
As I recall, there are five screws, one in each corner and one centered under the label. Rather than puncture the label with a screw driver blade, I peeled it back.
Rich
Alton Junction
Are all of your Tortii the same age? IIRC, Circuitron made a change to the copper traces on Tortoise machines some years ago when DCC was just getting popular. Seems the older models had a rather large contact area with a very small break area between the contacts. That was causing a brief short as the wiper crossed the gap. No one noticed with DC power because it was rarely picked up with analog power packs. DCC boosters would see the short because their internal circuit breakers respond so quickly. We were opening the older tortii and cutting some of the trace away to make a larger break area on those older machines.
Martin Myers
martin,
All of my Tortisesss are less than two years old, so I don't think that would be the problem. I may just take one apart to see what goes on in there. I have a couple of extras waiting for assignments!. i love to take stuff apart. Just dismantled my Canon LS150? digital camera as it didn't work any longer. Wow! Lots of stuff in there. Great little motor the size of a pencil eraser. Threw it all in the trash though.
I find it interesting that the ones you're having problems with are the ones where you've soldered directly to the pins on the Tortoise-- every single time I have had problems with Tortoises, it has been when someone's hooked them up using an edge card connector. Even proper eight-pin connectors have too much side-to-side slop for me to consider them reliable, much less the ten-pin or longer ones people sometimes use with a plastic filler at one end.
Shorting pins seven and eight or pins one and two on a Tortoise can be pretty devastating to a turnout decoder, since decoders are not designed to accept track power fed back into their throw outputs.
There was one extremely bad job recently where I was brought in as the DCC subcontractor and to wire up accessory decoders after the customer had hooked up edge connectors to his Tortoises. The side-to-side slop was so bad that at least once a week there were track power shorts which would only go away if you wiggled the plugs on the Tortoises one at a time until the short cleared. And this was after replacing half a dozen blown accessory decoders due to power being fed back into the decoder outputs from the aforementioned pin 1-2 or pin 7-8 shorts through the connector. I finally put my foot down and we removed all of the edge connectors. Once we soldered the wires directly to the pins on the Tortoise, the layout became reliable very quickly.
Personally, I think that using edge connectors with Tortoises introduces more problems than it solves. It's one more level of complication that can fail, and in most cases, you're not likely to need to replace a Tortoise during the life of the typical layout, anyway.
I'm curious how DCC Specialties overcomes this with their Hare and the Wabbit, because if they're using common edge connectors, I'd think that they'd run into these issues as well.
-Fritz Milhaupt, Publications Editor, Pere Marquette Historical Society, Inc.http://www.pmhistsoc.org
It may be the brand of edge connector, rather than the concept. I use them on my layout, and they are no problem. I do acknowledge the sideways "slop" in positioning, but once set correctly I have no problem with mine.
I rewired the turnout/Tortise as per the diagram and it works as it shoud.. I will go back and fjix all the other turnouts. I don't know why I haven't had a problem with the others (approx 30 Tortise's) unless they just worked in one position and in the other there was no power to the frog.
As I mentioned earlier this was one of the two that I soldered directly to the Tortise PC board. I haven't had any problems with any that have the edge connector and I will most likelly go back and put them on the two that don't have them. I use a thru type terminal strip for the wiring from the edge connector and print labels for each turnout. Makes it easy to trace, remove or repair. (The photo is an earlier one that doesn't have the internal switches wired yet.)
I really appreciate all your help on this. I guess it shows that you need to fully read the instructions.
Hey just a minute. It may not be a problem with the Tortise! Are there gaps in both diverging rails from the frog. A properly wired Tortise would short like you describe, if there is a missing gap.
I have over 60 Tortoises, but I have never used an edge connector. I consider them a waste of money. I just solder wires to the terminals at the work bench and install the Tortoises.