richhotrain The reason for that pause is the time necessary for the system to reset itself after the circuit breaker has tripped. The solid state circuit breaker trips because it senses a short faster than the mechanical relay on the auto-reverser can reverse the polarity. Rich
The reason for that pause is the time necessary for the system to reset itself after the circuit breaker has tripped. The solid state circuit breaker trips because it senses a short faster than the mechanical relay on the auto-reverser can reverse the polarity.
Rich
Joe, that is good point to raise.
In my case, the reversing sections are all longer than my longest train.
The reversing section on the turntable approach track is a short section but longer than my longest steam engine/tender.
Alton Junction
I'm sure you know this but is the train longer than the reverse section? If the train is longer than the gapped area you usually get the pause that you have been talking about.
Joe C
rrinker Actually, if any of the reverse sections are simple loop type arrangements, get a DPDT relay (or more, 3PDT and 4PDT relays are common, just ignore the extras, or use them for signal lights) and control it with switch machine contacts and use that to swap polarity in the reverse section, thus there would never be a short to sense, unless you tried to run against the switch lined for the other direction, in which case you're going to derail anyway.
Actually, if any of the reverse sections are simple loop type arrangements, get a DPDT relay (or more, 3PDT and 4PDT relays are common, just ignore the extras, or use them for signal lights) and control it with switch machine contacts and use that to swap polarity in the reverse section, thus there would never be a short to sense, unless you tried to run against the switch lined for the other direction, in which case you're going to derail anyway.
Yep, that is what I used to do before I bought my first AR-1.
At one time, I had no reversing sections on my layout until I installed that turntable and rotated it the wrong way.
Then, I got the bright idea to return my passenger trains in the same direction that they came from. That required two more AR-1s.
Then, I added a second bascule bridge on the one reversing section (a duckunder over an aisle) and I needed a fourth AR-1 (coulda used just the one but I had to have trains passing each other on the bridges and I couldn't risk simultaneous entering and exiting the reversing section.
The fifth AR-1 was required when I decided to have passenger trains enter and exit the station from two sides of the layout.
Ugh.
rrinker All because they were too lazy to code in an adjustable trip time......
All because they were too lazy to code in an adjustable trip time......
Amen to that.
You would think that they would have done that. After all, TTE carries a full line of Digitrax products.
And, they should put a warning on their web site that if you have auto-reversers with mechanical relays, don't buy the PSX circuit breaker.
Yeah, Randy, I am thinking along the same lines as you.
I have five AR-1s. Since my layout is one gigantic loop with a double mainline and a bunch of sidings and yards, I have three AR-1s on the mainlines to reverse directions of the locos so that they return in the same direction that they came from.
A fourth AR-1 became necessary because of my stupidity when I set up a Walthers 130' turntable some years back. That turntable does not require an auto-reverser unless you place an approach track in a bad location. I did not know that so I wound up needing an auto-reverser to solve the problem.
A fifth AR-1 is in my passenger station where the mainlines on the far side create reverse polarity as they enter the station. So the passenger station with its arrival and departure tracks on both sides became one large reversing section for simplicity sake.
Here is what I just did to partially solve the problem. Since my double mainline was going to be one of the power districts, I decided to bypass the PSX circuit breaker and let the 5 amp booster do its job. That eliminates the need for three PSX-ARs.
Now, I need one PSX and two PSX-ARs. I need to re-evaluate that turntable issue to see if I could relocate that approach track, reducing my PSX-AR need to one.
No shorts, ever. Autoreversers are reactionasry devices - fisrt the track shorts out, so the autoreverse attemps to change the polarity. If that corrects the short, great, off we go. Using the relay and switch machine contacts, there's never any short, by the time the train goes to cross the gaps, the polairty already matches and there's never a short. Using a relay and contacts makes it a preventative device instead of a reactionary one.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
I don;t think a 1 for 1 swap is going to get you what you need. How many reversing sections do you have? You need a PSX-AR for each of those, plus the other power districts. I thought you had 2 AR-1's in what you were making oen of the pwoer districts, that would mean splitting that up into two districts each with its own PSX-AR plus something for the partof that district that is not in either reverse loop. In other words, you really want to keep the PSX4 and add two PSX-ARs. Yes, the PSX-AR is also a breaker, but for a reverse loop it can ONLY power the track in the isolated reversing section, so the same PSX-AR can;t be used to protect say a staging yard with a balloon loop on the end, unless you make the whole thing the reverse loop (ok, that wasn;t a good example, you certianly COULD do that. OK, simpler example - basic oval with a reverse cutoff. You'd need a PSX for the oval part, plus a PSX-AR for the cutoff section that would be gapped at both ends. Just like any otehr autoreverser, any track downstream of the reverser can only be aprt of the reversing section. So don;t ship those PSX's back just yet, instead you need to get one PSX-AR for every AR-1.
So the PSX-AR's will do double duty protecting each of your power districts as well as operating the reversing sections?
Oh, isn't this peachy.
I just spoke to Tony's Train Exchange.
He indicated that the PSX does not work well with the Digitrax AR-1 because the PSX is solid state, and the AR-1 operates off of a mechanical relay.
So, by time that the AR-1 senses the reverse polarity, the PSX has already sensed a short.
That's why there is that 1 or 2 second short until the PSX has reset itself.
He was kind enough to exchange the PSX-4 for four PSX-ARs plus the difference in cash since the PSX-ARs are more expensive.
So, I asked for the weekend to decide what I want to do.
This has become a minor nightmare.
I should have left my layout as one big power district.
Here is an update on my problem.
I adjusted the TTC on each AR-1 to trip at 0.25 amps. I adjusted the current on each PSX to trip at 5.08 amps.
As soon as a loco crosses the gaps into a reversing section, the AR-1 clicks once so the setting is good. But the loco comes to a halt for 1 to 2 seconds, then resumes running.
The PSX flashes a red LED indicating the presence of a short.
I am on hold at the moment (actually, it has been 10 minutes) with Tony's Train Exchange hoping to get some help and advice.
Rich,
Does the PSX-4 have a sensitivity (response time) setting? If so, you may need to slow that down.
I have a couple AR-1's on my layout, but I use a PM42 instead of of a PSX. Three sections of it feed power districts on the layout, and the fourth section feeds only the AR-1's.
What has worked for me is to leave the PM42 at it's default trip current of 3 amps, but to slow down the response time for the section that feeds the AR-1's to it's slowest setting.
If you can do something like that with the PSX it may be worth a try.
I feed my auto-reversers, older PS-REV units from Tony's Trains, directly from the main bus outputs, not through my PSX-4. I think that's the preferred configuration.
But, I have the same problem once in a while. Once a train has gone through once, it doesn't stall again unless I have a short which resets everything, or I power off intentionally.
This has never risen to the point where it's annoying enough to work on and fix, but one of these days....
So, suggestions would be appreciated.
It takes an iron man to play with a toy iron horse.
Raise the trip current on the PSX units?
I am in the process of dividing my layout into four power districts.
Three of the four power districts each have an auto-reverser, a Digitrax AR-1, within the power district to control a reversing section.
Each power district is protected by a PSX circuit breaker (a PSX-4 to control the four power districts) set to factory default at 3.81 amps.
The entire layout is powered by an NCE PH-Pro 5 amp system with a single booster.
I am running into problems as a loco crosses into or out of a reversing section. There is a pause which I did not have before as the system tries to recover from a detected short due to reverse polarity. Sometimes, the system cannot recover.
I have fiddled with the TTC screw on the AR-1 without success. Am I going to be able to make this work?