Tomix 5574 TCS unit and reverse loops

[doodlebugdepot]

I’ve been looking at the Tomix 5574 TCS automatic unit and thinking of ways in which it can be used. I have heard that with Tomix track it is apparently fairly easy to operate a reverse loop on DC - just throw the points and reverse the polarity together and the train should continue on without stopping or needing special wiring because of the “fully power routing” turnout, correct?

 

My question is about mode 2 of the automatic unit. The train is meant to start from the center, drive to one end and stop, then reverse into a passing loop, then repeat. What I am wondering is if this mode might be able to run as a reverse loop instead. Rather than reach the end of a straight line, the train would stop at the sensor in the middle of the reverse loop, the unit would throw the switch and reverse the polarity, then the train would continue onwards as normal. I was thinking this mode might be able to run a simple layout consisting of two reverse loops connected by a single line, for a trolley or small train. Could anyone confirm with me if this might work, and if I have a correct understanding of how Tomix reverse loops work?

 

Thank you very much. 🙂

[katoftw]

I don't think that will work. The system cannot reverse polarity with a loop.

[cteno4]

I don hink ive seen any of the TOMIX control systems doing polarity switching required for reversing loops. @brill27mcb may have some ideas.

 

jeff

[brill27mcb]

Hi, I think this is very possible. Give me some time to play with some ideas and I will get back to you. There are some tricks you can play with the Tomix Automatic Operation Unit logic, and it's the logic sequence that matters, not the actual shape of the layout. I've been doing Tomix TNOS for the last few years and need to refresh my memory of what the simpler Automatic Operation Unit requires in terms of needed sensor inputs.

 

Rich K.

[KateM]

This is a basic example of DC reversing loop that is fed (and thus controlled) via a power-routing turnout. Automating the double loop layout should be very doable with Mode 2, one sensor in each reversing loop (exact position to be determined experimentally) in slots S1 and S4, and one feeder connected somewhere in between the two turnouts.

[brill27mcb]

OK, yesterday I was able to work out the details and test with actual layouts using my Tomix 5563, the earlier Automatic Operation Unit (AOU). The newer Tomix 5574 AOU is said to have the exact same logic, just more amperage for the train. I can confirm that you can use AOU Mode 2 (designed to operate a point-to-point layout with center passing siding) to instead operate what seems to be just the opposite - a layout with two reverse loops and a center single track. The concept works and I have developed two alternative schemes:

 

Alternative 1 (above) has all 4 TCS sensors within the reverse loops. (My plan shows Tomix Mini Rail and the S37 Wide Tram TCS sensors; you can use any Tomix track and sensors that you want to use, and shape the layout as you wish.) The track power feeder F1 must be oriented as shown and in the single-track center section of the layout. When the train (or trolley in my case) stops at a sensor, it must not be on another sensor or on a track switch (turnout, points - call them whatever you want - I'll use points since the AOU cable receptacles for them are marked P1 and P2). The points must be the newer Fine Track points with the "complete power routing" feature, meaning you should see a built-in insulated rail gap on both continuous outer rails across from the frog.

 

While the train is stopped at sensor S1 or S4, the AOU in Mode 2 turns off track power, throws P1 and P2, reverses the track power polarity, and then restores track power. In all AOU layouts there is only one track feeder, so this reversing of track polarity affects the entire layout; however, the throwing of the points "re-reverses" the polarity within the return loops, negating the direction change. So the loops always operate in a clockwise direction, while only the center single track section of the layout actually changes direction. It's kind of an unnecessarily complicated "Rube Goldberg" solution (https://en.wikipedia.org/wiki/Rube_Goldberg_machine), but it does let the AOU operate this design of layout.

 

A lot of people have wanted to have a way to automate a twin reverse loop layout. Examples of when reverse loops work better than point-to-point include a locomotive-hauled train, a single-end trolley or tram with operator controls only at one end and possibly doors only on one side, or any trolley or tram with roof-mounted trolley poles instead of a bi-directional pantograph.

 

This is my Alternative 2, which moves the optional "stop-only" sensors S2 and S3 onto the center single track section. Each will stop the train in one direction only. Sensors S1 and S4 must remain in the reverse loops.

 

This has been an interesting puzzle to work out! It's the second "hack" that I have figured out to use the Tomix Automatic Operation Unit to operate a layout for which it was not planned. Here's the first:

 

 

Rich K.

Edited June 19 by brill27mcb

[cteno4]

Excellent Rich! I figured if anyone could figure it out it would be you.

 

kudos

 

jeff

[doodlebugdepot]

On 6/17/2024 at 9:27 AM, brill27mcb said:

Hi, I think this is very possible. Give me some time to play with some ideas and I will get back to you. There are some tricks you can play with the Tomix Automatic Operation Unit logic, and it's the logic sequence that matters, not the actual shape of the layout. I've been doing Tomix TNOS for the last few years and need to refresh my memory of what the simpler Automatic Operation Unit requires in terms of needed sensor inputs.

 

Rich K.

 

Thank you so much for all the thorough and detailed response! I didn't expect to not only have it tested but have alternatives proposed as well. I have actually been to your website in the past. It's a very useful resource. TNOS seems quite complicated, at least to a beginner, so I think the AOU will be a good fit for me. I really appreciate the help. Thank you for everyone else who chimed in, too. I'm glad to know it would work. 🙂

[brill27mcb]

You are welcome, and now it's here for anyone else to find, too. You had the insight to think that this could be possible, and so did katem and I.  katem and I seem to share an interest in understanding Tomix and other products and investigating their possibilities, especially sectional track designs and control systems.

 

Rich K.

[brill27mcb]

And now there is a video, done in my signature style of highly informative, but low production quality:

 

 

Rich K.

[KateM]

Great job, Rich! Love the video 🙂

 

Would you mind also doing the alternative with one sensor in the middle (connected to both S2 and S3) and the alternative with just one sensor in each loop (nothing connected to S2 and S3)?