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Discussion Starter #1
to connect Tortoise switch machines and MTH AIU (DCS switch and accessory controller)

We had hoped to put this issue off for a while but decided to handle it now.

Per Barry’s book, this is what is recommended to do the job.

My knowledge about relays is rather limited (like close to zero... but there is no time like the present to learn.)

We probably need to handle 10-12 turnouts and, depending on some answers we should have Tuesday, possibly more. The Tortoises are powered with 10-12 volts.

Thanks for the help.
 

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Discussion Starter #3
Dennis I haven’t a clue. Barry Broskowitz wrote the book on DCS and he says, “MTH suggests attaching Tortoise slow-motion switch motors to the AIU by using a latching relay. The following diagram shows the connections between the AIU and an NTE 50 series latching relay.”

He then explains how the relay works... magnets hold the armatures in position and each latches when current is applied, etc.

When I had a boat, relays were used in various applications and I understand what they do, etc but I was hoping that we had someone here who had experience with the DCS Tortoise application and could say, as GunrunnerJohn often does, “Oh yeah, you need this and here is what to get.”

I appreciate your help and you obviously know a lot more than I do. I am not much help. I expect that I can get an answer on OGR and Barry is often there but I wanted to try here first. Any ideas?

Bill
 

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I can understand why you would need a latching relay with Tortoise switch machines but R50s are way overkill besides being very expensive. I have to assume an AIU only outputs a pulse rather than a steady voltage. A latching relay will take that pulse and keep the contacts closed until it receives a second pulse.
The Tortoise machines draw about 25 ma after the points are closed, less while its changing position so a solid state latching relay would be a better alternative.
I can't give you a number yet, maybe when I get some free time I can look them up.

Pete
 

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Thats a way better alternative. NTE R50s list for about 28 bucks each.
BTW While you can keep continuous power on the Tortoise, its designed for that, you don't have to. If you put slightly heavier piano wire on them they will stay closed even without power.
That catch here is it takes a pulse of 2-3 seconds for the points to close and likely the AIU won't do that on its own.

Pete
 

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Discussion Starter #8
Thanks guys. I note that there is a note near the bottom, “this method... May be more of a thought provoking idea than a practical solution”

It appears to work okay in the video and the cost is certainly reasonable. Now if I can figure out what the directions are doing I will order some parts. Any idea if anyone has used it for the application?

Estimate on how long it would take to wire one up?

Pete you are correct about the AIU. It is momentary and can’t handle the delay. We are using heavier wire which holds firmly in place with power off.

Thank both of you for the help.
 
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