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2- Tortoise switch machines on one DS74 Port

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2- Tortoise switch machines on one DS74 Port
Posted by Redhawk95 on Tuesday, December 14, 2021 10:18 AM

Hey guys so I am working on the staging yard on a layout I just started. I am using tortoise switch machines with DS74 controllers. i know a DS74 has 4 ports for 4 switch machines. I was wondering can you hook up 2 tortoise switch machines to a single port on the DS74. Typicaly in a yard you would want the switch to throw on both ends no matter what so why not hook them together and save money on how man DS74s you use. Just wondering if anybody has tried it?

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Posted by Steven Otte on Tuesday, December 14, 2021 4:32 PM

Alternative suggestion: Tortoises have an internal double-pole, double-throw switch that switches with the direction of the throw arm. Run a 12V DC power supply to the single pole of that internal switch and run wires from the other poles to power the other Tortoise. When the DS74 lines the first Tortoise, its internal switch will line the other.

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Posted by York1 on Tuesday, December 14, 2021 4:36 PM

Redhawk95,

Welcome to the forums.  I don't have anything to add to the advice Steven Otte gave, but I hope you continue to post to this forum about your layout.

If you're able to, I also hope you can post some photos of things you are working on.  I love pictures of layouts under construction.

Welcome

York1 John       

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Posted by Lee 1234 on Tuesday, December 14, 2021 5:27 PM

https://www.digitrax.com/media/apps/products/stationary-decoders/ds74/documents/DS74_flattened_rev.0.pdf

Looks like 70 ma max to me on the DS74.  How much amperage are your Tortoises pulling?

Lee

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Posted by CharlieM on Tuesday, December 14, 2021 6:28 PM

Each Tortoise draws a bit more than 20 ma. when stalled; a lot less while moving. Two Torti on one output should be no problem. Double ended yard tracks or sidings are a great application for this.

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Posted by PC101 on Thursday, December 16, 2021 11:29 PM

Redhawk95
Typicaly in a yard you would want the switch to throw on both ends no matter what so why not hook them together
 

Looks like you got the answer on the DS74.

I will comment on your words in the blue box quote above. I will add that I like to have independently controlled switchs/turnouts at each end of a yard track or siding track.

I could be bringing a train in the ''east end'' of that track and if the ''west end'' switch/turnout is lined for that same track, no other train can go past the ''west end'' switch/turnout without running in to that same track or running against the switch/turnout.

Likewise if I take a ''west bound'' train off the main and into a siding and that train's tail end is not clear of the #2W switch/turnout yet and is still moving in to the siding, no other ''east bound'' train can pass the #2E switch/turnout at the other end. 

Just another thought. 

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Posted by John-NYBW on Thursday, December 16, 2021 11:56 PM

Steven Otte

Alternative suggestion: Tortoises have an internal double-pole, double-throw switch that switches with the direction of the throw arm. Run a 12V DC power supply to the single pole of that internal switch and run wires from the other poles to power the other Tortoise. When the DS74 lines the first Tortoise, its internal switch will line the other.

 

My first experience with Tortoises was using them for both turnouts of a crossover. It works quite well with a 12V DC power supply. Originally, I used Atlas under mount switch machines but I found that when both were hooked to the same Atlas control box, the points wouldn't always get thrown completely resulting in derailments. Not a problem at all with the Tortoise machine. They have worked flawlessly for the past year since I installed them. I'm now preparing to replace some other problem Atlas switch machines with Tortoises. 

UPDATE: I should have mentioned that I simply wired both Tortoises to the same DTDP switch and that has worked just fine. I hadn't thought of using one Tortoise to flip the other. It might be six of one or half a dozen of the other. I'm about to put Tortoises on another paired turnouts and might give this a try. It's simply a matter of making sure the polarity matches for both turnouts but you have to do that no matter which method you use. 

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Posted by gregc on Friday, December 17, 2021 7:09 AM

we just completed building an interlock panel that uses pairs of LM324 op-amps to drive pairs of tortoise machines (crossovers).  Tortoise machines draw the same current as an LED

greg - Philadelphia & Reading / Reading

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Posted by crossthedog on Friday, December 17, 2021 12:16 PM

John-NYBW
My first experience with Tortoises was using them for both turnouts of a crossover. It works quite well with a 12V DC power supply.

This worked for me, too. There was a lengthy string a couple months ago and one of the digressions involved my questions about how to wire this. I actually ended up using a 9-volt wall wort, which makes the switches move r-e-a-l  s-l-o-w. Here was the post from Rich that helped me get my head around it, in case you need this.

richhotrain

 

 
crossthedog
 
richhotrain
Wire the single DPDT with two wires to the DC power source. Wire the X-pattern on the DPDT. Wire the center terminals on the DPDT as the power source for the Tortoises. Now wire the Tortoises on terminals 1 and 8 and connect those four wires to the two wires extending off the center terminals of the DPDT. That's it. 

@Rich. Comme ça?

 
 

 

 

Oui

 

Rich

 

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Posted by John-NYBW on Friday, December 17, 2021 6:16 PM

crossthedog

 

 
John-NYBW
My first experience with Tortoises was using them for both turnouts of a crossover. It works quite well with a 12V DC power supply.

 

This worked for me, too. There was a lengthy string a couple months ago and one of the digressions involved my questions about how to wire this. I actually ended up using a 9-volt wall wort, which makes the switches move r-e-a-l  s-l-o-w. Here was the post from Rich that helped me get my head around it, in case you need this.

 

 
richhotrain

 

 
crossthedog
 
richhotrain
Wire the single DPDT with two wires to the DC power source. Wire the X-pattern on the DPDT. Wire the center terminals on the DPDT as the power source for the Tortoises. Now wire the Tortoises on terminals 1 and 8 and connect those four wires to the two wires extending off the center terminals of the DPDT. That's it. 

@Rich. Comme ça?

 
 

 

 

Oui

 

Rich

 

 

 

 

That's how I did mine but I also used terminals 2,3,4 to power the frog. I hooked 2&3 to my DCC bus lines and 4 to the frog. Amazon is supposed to deliver a new soldering iron today and then I will add three more Tortoises, two of which will be paired. 

 

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Posted by crossthedog on Friday, December 17, 2021 6:43 PM

John-NYBW
That's how I did mine but I also used terminals 2,3,4 to power the frog.

I've done a few of mine that way, too, but I didn't figure that part out until later (EDIT: Full disclosure: and I didn't figure it out...some kind soul here told me how to do it). I intend to go back and power all my frogs using posts 2, 3, and 4, but I haven't yet because it means I have to get under the layout with the soldering iron (bliiyeccchh). From now on, before I affix a Tortoise to the underside of the layout I solder foot long wires to posts 1, 2, 3, 4 and 8 and let 'em hang there until I need them.

-Matt

 

 

Returning to model railroading after 40 years and taking unconscionable liberties with the SP&S, Northern Pacific and Great Northern roads in the '40s and '50s.

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Posted by John-NYBW on Sunday, December 19, 2021 7:01 AM

crossthedog

 

 
John-NYBW
That's how I did mine but I also used terminals 2,3,4 to power the frog.

 

I've done a few of mine that way, too, but I didn't figure that part out until later (EDIT: Full disclosure: and I didn't figure it out...some kind soul here told me how to do it). I intend to go back and power all my frogs using posts 2, 3, and 4, but I haven't yet because it means I have to get under the layout with the soldering iron (bliiyeccchh). From now on, before I affix a Tortoise to the underside of the layout I solder foot long wires to posts 1, 2, 3, 4 and 8 and let 'em hang there until I need them.

 

-Matt

 

 

 

I intended to power frogs whenever I retrofit a turnout with a Tortoise but then I remembered if you power the frog, you need to insulate the diverging end of the turnout and the location of some of these turnouts makes that very difficult so I'm only powering frogs on a case by case basis. 

I try to do all the soldering before installing the Tortoise but if you are powering a frog for a turnout you've already installed, you have no choice unless you want to disconnect and reinstall it. I used to solder my track feeders to the bus lines before I discovered suitcase connectors. That was 10-15 years ago. At my age, it's a chore to work under the benchwork now and I wouldn't want to do it with a soldering iron in my hand. 

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Posted by Redhawk95 on Monday, December 20, 2021 10:22 PM

Thanks for all the help guys. I'll take in all the info and see what might work best. 

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Posted by opiewan on Wednesday, May 1, 2024 7:41 PM

Long time lurker, first time poster here. Admins, if you'd prefer that I start a new thread on this rather than replying to a two plus year old thread, I will gladly do so.

I have run into the exact same use case as the original poster, where I have a stationary decoder (specifally the Digitrax DS74) powering my tortoises, and have a crossover where I'd like to employ your solution of using one tortoise to control the other, but am having some trouble visualizing a couple of things as I'm still learning and I am hoping you (or anybody else reading) can chime in.

So this crossover has a tortoise on either end. One of the tortoises (the 'master') would be connected on ports 1 + 8 to the DS74. How to connect the other tortoise (the 'slave') is where I start to get fuzzy.

I get that there is two internal SPDT on the tortoise on ports 2/3/4 and 5/6/7. I also see that the single poles are on 4 and 5. So I guess I have two questions here.

First, lets say I pick the SPDT on ports 2/3/4. Do I hook up 2 and 3 on the master to 1 and 8 on the slave? If not, then what should these hookups be?

Second, you mention running a 12V DC power supply to the single pole, which in my example I think is port 4. Can you expand on this for a not quite intermediate electrician like myself? I have an old DC power supply laying around that I can use, but it has two wires. Which do I connect to the tortoise? Or do I need to do something else here?

Thanks in advance to anybody who can throw ideas my way. Happy railroading!

John

 

 

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