Tale of two TIUs

 I really know nothing about what's going on here. The only thing I could comment on to be fair, would be to also have another TIU connected to maybe a programming track or small layout and compare the results over time. I'm just thinking that there maybe something about the equipment, layout or wiring causing some unknown issue?

Engineer-Joe posted:

 I really know nothing about what's going on here. The only thing I could comment on to be fair, would be to also have another TIU connected to maybe a programming track or small layout and compare the results over time. I'm just thinking that there maybe something about the equipment, layout or wiring causing some unknown issue?

Looks like he did just that...

Adrian! posted:

 As a control case, I also ran a TIU in active mode over the same period.

Roving Sign posted:

Engineer-Joe posted:

 I really know nothing about what's going on here. The only thing I could comment on to be fair, would be to also have another TIU connected to maybe a programming track or small layout and compare the results over time. I'm just thinking that there maybe something about the equipment, layout or wiring causing some unknown issue?

Looks like he did just that...

Adrian! posted:

 As a control case, I also ran a TIU in active mode over the same period.

I would guess that this was using the same equipment and/or layout though? If something was causing this issue just for him, we'd read into this post that everyone would then experience this issue. You need to also look at other layouts and equipment before judging by using strictly these results.

 In other words, what exactly caused this to happen?

I can think of a club that uses very old transformers for power supplies. I'm not sure they have the proper protection wired in. So the TIUs could be exposed to severe power surges without proper protection that a normal user might not expose them to.

 I'm not saying that's what happened here. All that is posted is some results without proper justification of why it happened. Maybe the old post has explained it better?

Very interesting.  If you remove the Passive TIU to a bench setting the amplitude is still just 12; or does the lay out effect it?  What the next test should be is a controlled track (loop) that no one runs on but you so that you can record derailments or spikes while conducting the test.  Meaning, if you ran the same test with no derailments or bad behavior on that loop, does the TIU degrade in passive just based on run time alone? G

GGG posted:

Very interesting.  If you remove the Passive TIU to a bench setting the amplitude is still just 12; or does the lay out effect it?  What the next test should be is a controlled track (loop) that no one runs on but you so that you can record derailments or spikes while conducting the test.  Meaning, if you ran the same test with no derailments or bad behavior on that loop, does the TIU degrade in passive just based on run time alone? G

Hey there. Forgot to mention that.

1. Yeah when I take it back to the bench it's still 12V. It's a one way trip.

2. About the same time I put a new TIU in my setup and test track at home (where I don't have the bad behavior). It's still measuring out at ~17.5V like it was new out of the box. I think it's safe to say the bad behavior drives the descent from 18ish to 12ish.

Engineer-Joe posted:

Roving Sign posted:

Engineer-Joe posted:

 I really know nothing about what's going on here. The only thing I could comment on to be fair, would be to also have another TIU connected to maybe a programming track or small layout and compare the results over time. I'm just thinking that there maybe something about the equipment, layout or wiring causing some unknown issue?

Looks like he did just that...

Adrian! posted:

 As a control case, I also ran a TIU in active mode over the same period.

I would guess that this was using the same equipment and/or layout though? If something was causing this issue just for him, we'd read into this post that everyone would then experience this issue. You need to also look at other layouts and equipment before judging by using strictly these results.

 In other words, what exactly caused this to happen?

I can think of a club that uses very old transformers for power supplies. I'm not sure they have the proper protection wired in. So the TIUs could be exposed to severe power surges without proper protection that a normal user might not expose them to.

 I'm not saying that's what happened here. All that is posted is some results without proper justification of why it happened. Maybe the old post has explained it better?

We've done whatever we can to protect the TIUs.  We have 5 TIUs in our layout and all show this behavior, I just picked one data-set to share, I have 4 similar ones. All of the power comes from 4 PH180 bricks per TIU (1 per channel) powered from one of those high-end home theater surge protectors and line filters (north of $150). The 4 PH180 bricks feed 4 PSX-AC units which then enter the layout through a 22uH choke on the active line.

So overall 5 fancy surge protectors feeding 20 PH180 bricks and 20 PSX-ACs feeding 20 channels on 5 TIUs. The entering sine-wave has a THD ~ 0.1-0.2% since there's no chopping or anything along the way. The PSX-AC is pretty benign on the harmonics also.

Our club is really really rough on the layout compared to most. We're sure this is why it's happening, just not sure how to address it.

Adrian! posted:

GGG posted:

Very interesting.  If you remove the Passive TIU to a bench setting the amplitude is still just 12; or does the lay out effect it?  What the next test should be is a controlled track (loop) that no one runs on but you so that you can record derailments or spikes while conducting the test.  Meaning, if you ran the same test with no derailments or bad behavior on that loop, does the TIU degrade in passive just based on run time alone? G

Hey there. Forgot to mention that.

1. Yeah when I take it back to the bench it's still 12V. It's a one way trip.

2. About the same time I put a new TIU in my setup and test track at home (where I don't have the bad behavior). It's still measuring out at ~17.5V like it was new out of the box. I think it's safe to say the bad behavior drives the descent from 18ish to 12ish.

This is the point I'm trying to make for anyone new who just happens to look at this post. Maybe they will think this degrade will happen to theirs automatically?

I do bet other's may have this happening. It is important to get to the root cause and not just squash this post. From my past experience with this forum, many haters will emerge just to bash what they don't understand. It's always refreshing to learn new things and help develop a product with an open mind. I have read some struggles with other clubs that lead me to believe this problem is not totally new. Another member suggested that newer (certain version?)" L" TIUs at that time, gave his club troubles.

Well I know of someone with a large layout all DCS in passive mode and he won't use those PH180 bricks..he swears by the 135's as having better circuit breakers.

Adrian! posted

Our club is really really rough on the layout compared to most. We're sure this is why it's happening, just not sure how to address it.

I have to ask what led you to make this statement? In what way is the club so rough?

Are the members adding stuff to the track while it's powered?

Are there a lot of derails?

I can only guess and find it interesting, so I asked.