Thanks again for all the input you folks have given me regarding my reversing loop / staging.
I now have four stub end and two double end tracks (these two are the reversing loop) on my upper level staging. Lower level is still pending, but will most likely be a mirror of the upper.
However, after reading any number of threads here, I have additional questions:
I do have a power buss running to staging that IS NOT circuit protected…Thinking that either a PM-42 or two PS-Rev will take care of the protection needs.
Here are my big questions:
1)) For the money is Tony’s PS-Rev that much better then the others?
2)) Can the PM42 be used as protection and a reversing unit at the same time using two protected circuits to power two reversing circuits?
3)) With the off pike staging truly “off pike” in another room, would it be advantageous to have the stub end tracks protected separately from the rest of the main trackage? I’m thinking yes, but would like a bit of input from you experts.
With the budget tighter then ever…If the PM-42 can do as questioned…I can accomplish my needs for half (or less) the expense.
If going for the additional protection (as in question #3), a PM-42 and two AR-1's is still less costly then going the PS route....Which brings me back to question #1
What scale? A friend of mine has his N scale layout happily chugging along on a PM-42 and a pair of AR-1's for his reverse loops. Absolutely no trouble.
It was originally listed as Ok for one PM-42 section to feed another, so one could be the breaker and one the auto-reverse. However, some peopel ahd trouble with that and it is no longer a recommended configuration - they even took it out of th emanual. But some people are runnign liek this with no problems at all. I'd say don't do it, and use AR-1's for the reverse loops. Keep in mind the AR-1 is JUST an autoreverser, if there is a short rather than just a train goign aroudn the loop, it will chatter constantly and never totally cut the power. It needs to be fed from a PM-42 section to provided short protection as well as the reverse action.
Benefits of the PM-42 solution, if you're usiang a Digitrax system, if you plan to hook up a computer at some point, you will get messages about shorts as the occur, plus you can manually switch powerr on and off to each section - you can make a virtual contrl panel in JMRI that has 'toggles' that compeltely shut down the power to track area, simply by sending commands to the PM-42.
Benfits of the Tony's products, thay are compeltely solid state, there are no relays to ever fail
The AR-1 is more fully and easily adjusted as to trip current than the PSX-AR - AR-1 uses a potentiometer you just turn until it trips properly for a train moving through, the PSX-AR only has fixed steps programmed either with CV settings or jumpers.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Thanks for the come back and your input Randy…Sorry I didn’t give a bit more detail.
I’m in HO with a relatively small pike of about 16’ x 16’ in the Trainroom. I’m running DCC with an older Digitrax BigBoy system powering four districts (upper, lower, peninsula and the helix) with a PM 42.
The buss to staging is feed from the main to the Trainroom PM 42, running about 32’ to the back room of my Sawshop. If I do use a PM 42 at staging, I assume that I will also have to run a ground back from that PM 42 to the booster. Right?
BTW, all of the main DCC power busses are of #12 stranded copper, with the longest run being about 48’.
Hope this sheds a bit more light.
As Randy pointed out, Digitrax no longer recommends using one section of a PM42 as short protection for an autoreversing section on the same PM42. An AR1 would be the safest choice but could be cut in later if the PM42 scenario doesn't work out. PSXAR's could also be substituted later. For a drawing of the "old way" look up the Digitrax online manual for the original PM4.
You would need that ground wire from the PM42 back to the DB100 (+,a). Same as on your existing PM42. You will also want to set the board ID on each of your PM42 if monitoring via computer is planned. This come in handy if a change to the speed or current threshold is needed as it can be done right from the computer. Much easier than watching the PM42 led's blink.
Martin Myers