Hi,
I'm in the middle of demolition of the HO layout, and am looking at my DC wiring with all its blocks and toggle switches and electrical stuff. As the new layout is DCC, much of this wire is pretty much worthless and will be thrown out. My question involves toggle switches........
The new layout will incorporate "shut off" toggle switches for the staging yard and engine terminal tracks, as well as a three foot programming track. I "assume" a DPST toggle would do the job, but what kind, size, and placement do you all use? Also, I "assume" that the wires going to the track would be the same gauge as regular feeder wires (# 22 or #20), and you would want them as short as possible. What do you all recommend that will do the job, and look nice as well?
Ha, my break is over, got to get back to the grunt work........
Thanks,
Mobilman44
ENJOY !
Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central
The same toggles you are tearing out of the DC control panels shoudl do the trick quite nicely. No need to buy new ones. For the engine temrinal, if you have the turntable control and so forth on the fascia, then the toggles should be there, probably on the line on the diagram that indicates which track it controls. Staging, I dunno. If you are going to have a 'mole' type of staging where someone hides in there and sends out the required trains, then somewhere near that location. I would also use heavier wire than feeder wire because you're goign to have a toggle controlling a section of track that will likely have more than one feeder. If it's just one engine stub off the turntable, one feeder is fine, but for a staging track you shoudl follow the same 3-6 foot rule as the main.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
You should use switches rated at the amperage of the power district it's connected to. That being said, I get good service out of submini toggle switches similar to these DPDT switches from Radio Shack. http://www.radioshack.com/product/index.jsp?productId=2062499Haven't burned one up in twelve years with DCC. We have a dozen of them on our club's yard control box as well.
You want a double pole switch. Single throw is great, but double throw will work too. One side has nothing connected so it's off when thrown that way. Your present toggles are most likely sufficient.
Martin Myers
I use DPDT switches in all of my DCC blocks. I still like to be able to shut off a section to work on it, troubleshoot, or for any other reason. I don't use them often but they can come in handy.
Engineer Jeff NS Nut Visit my layout at: http://www.thebinks.com/trains/
Your current toggles should be fine. I used SPST (click on-click off) pushbuttons.
I mounted a terminal strip behind the panel, and used 20 gauge wire from the switches to the strip and 16 gauge wire from the strip to the track. Probably a little overkill.
Nick
Take a Ride on the Reading with the: Reading Company Technical & Historical Society http://www.readingrailroad.org/
mobilman44The new layout will incorporate "shut off" toggle switches for the staging yard and engine terminal tracks, as well as a three foot programming track.
For the programming track, should he not use only a DP/DT toggle to eliminate any possibility of there being a connection between the main and the programming track during the programming process?
Best practice is a separate programming track and 0-5-0 the loco to powered track.
Crossing from a powered track to the programming track would effectively feed full power into the program outputs of the command station. Not good for the command station.
I don't recall hearing that before (about not running locos from run tracks to program track) but it seems to have some validity. I would like to hear from other on this, and may rethink my placement of the programming track.
As much as it seems 'cool' to have your programming track as part of the engine terminal, it usually leads to trouble. If you accidently run an engine across the gap - You will mess up a decoder or even the command station. A LHS would not listen to me and did just that. Someone forgot to throw the DPDT toggle and messed up the decoder in a new BLI engine. A 'decoder 'reset' fixed that one.
If you are sure you want the programming track integrated in your engine service area, look a Joe Fugates site and wire up the track as he describes:
http://siskiyou-railfan.net/e107_plugins/forum/forum_viewtopic.php?2865.post
Jim
Modeling BNSF and Milwaukee Road in SW Wisconsin
My programing track isn't connected to the layout, I use a piece of track mounted on top of my main control panel, housing the command station.
A friend of mine has his program track integrated into his engine terminal and has on more then one occasion reprogrammed all his engines to the same address.
mfm37Crossing from a powered track to the programming track would effectively feed full power into the program outputs of the command station. Not good for the command station.
This comment raises an interesting point that had not occurred to me. My home "railroad" and the club I belong to both have the programming track as a stub off the main line. In both cases the programming track is isolated by an insulator in each rail. Both systems are NCE PowerhousePro.
I understand the concern about possibly programming everything on the railroad should an engine span the insulators. Putting this issue aside, the back feeding of the programming side of the command station is of interest. I just went and reviewed the NCE manual. They show the programming track isolated from the main with insulators and the dp/dt switch. In the verbal description of the hookup they talk about installing the insulators. Then they mention that you can install the dp/dt switch "if desired". I don't see any warning about back feeding the programming side of the command station.
So, the questions are: has anyone actually had an issue doing this without the dp/dt switch; is there really a possible problem with the back feeding issue and the manual neglects to give this warning; or is the dp/dt switch not really a requirement?
Thanks.
I run my programming track as a stub siding with a simple DPDT switch. Page 27 of the Super Chief manual shows this configuration, minus the DPDT switch. The diagram has a simple double gapped set of rails between the programming track and the mains. Here's a couple of similar articles from Digitrax's knowledge base:
http://www.digitrax.com/kb/index.php?a=1340
http://www.digitrax.com/kb/index.php?a=1318
I perosnally have never had any issues with my current arrangement. The key, as mentioned previously, is to have just one locomotive on the programming track at a time.
To be absolutely safe with the program track you use a 4PDT toggle so that there is a dead section at least as long as your longest loco between the program track part and the main line part:
--program area----+---dead section---+---rest of layout--
The 'dead section' is engergized when the toggle is in the 'run position - then the entire siding is powered. In program mode, the program area is conenct to the program track outputs, the dead section is just that - dead - and then the rest of the layout is still conencted to the track outputs. This makes it all but impossible to connect the program track to the main track . You would have to bridge two sets of double gaps to do so - so if the dead section is longer than your longest loco, it can't happen unless you have some sort of lighted train with jumpers between each car.
A 4PDT switch has 4 sets of connections instead of 2. one pair is wired to the program track in the various methods mentioned, so that the track connects to the center terminals, and one side goes to the program track outputs on the command station, and one side goes to the track outputs. The other pair of terminals is used for the dead section. The middle terminals go to the dead track, and on the same side as where you connected the main track wires, another set of wires to the main track are connected. The opposite side terminals are left unconencted to the dead track is 'dead' when the switch is thrown to the program mode.
rrinkerTo be absolutely safe with the program track you use a 4PDT toggle so that there is a dead section at least as long as your longest loco between the program track part and the main line part:
Randy, I understand what you're saying, but safe from what? My question/concern relates only to the possibility of back feeding the programming side of the command station. As I and another poster above have done, the stub programming track is only isolated by the two insulators. This seems to be the general connection method as shown in both the Digitrax and NCE instructions, with the dp/dt switch shown as an option.
So again I ask, is there really an issue with the back feeding of the programming side of the command station that the manufacturers have not warned us about?
Thanks
I'll throw in my 2 cents.
Let's think about what happens with a single set of gaps isolating the programming track. First, the locomotive on the programming track should never move - supposedly there isn't power to move the motor. Assuming this is correct, the spanning of the gaps would most likely happen from a locomotive on the main inadvertently moving into the programming section. This assumes no operator error by placing the locomotive to be programmed accidently spanning the gaps.
When the locomotive wheels on the engine coming from the main spans the gaps, several things happen. First, the programming and main tracks are now one. Whether the backfeed between the 2 outputs of the booster is sufficient to be destructive, I can't say. If it is destructive, one would hope the circuit breaker would trip. Second, full power is now on the programming track. The locomotive on the programming track has power to move if so commanded - a possible meet between the locomotives. third, if in the middle of programming a decoder, the decoder will likely have its brains "scrambled" at a minimum. You have know way of knowing what values are being written to the CVs that have been opened for writing. At the same time, there is a possibility the locomotives on the main may also get their corresponding CVs opened and written to at the same time.
Staggering the gaps by 1/8" or so could help by preventing both rails being spanned at once. But even one rail gap being spanned allows one side of the circuit to be common. This may or may not be a problem. The 4PDT solution with the dead section absolutely prevents the gap spanning. The risks, costs, and benefits are yours to assess.
Fred W
maxman rrinkerTo be absolutely safe with the program track you use a 4PDT toggle so that there is a dead section at least as long as your longest loco between the program track part and the main line part: Randy, I understand what you're saying, but safe from what? My question/concern relates only to the possibility of back feeding the programming side of the command station. As I and another poster above have done, the stub programming track is only isolated by the two insulators. This seems to be the general connection method as shown in both the Digitrax and NCE instructions, with the dp/dt switch shown as an option. So again I ask, is there really an issue with the back feeding of the programming side of the command station that the manufacturers have not warned us about? Thanks
If you DO feed track power back into the programming track, you'll probably destroy the program track output, regardless of brand. The program track outputs are low power outputs and are not able to handle voltage feedback. It's not even jsut a DCC thing - a lot of transistor throttle designs have a diode int hem to protect the output transistor from another throttle connected to the same block. But not all DIY designs have this, and not many if any at all of the commercial ones have this. So you do not want under ANY circumstances allow full track power to feed back into the program track. If you're careful and make sure you always go to the far end of the program track you probably won;t have a problem. Buf if the insualted section is short and particularly if you use automated programming such as with JMRI, you need to really watch out. Some locos, mostly those with top quality motors, will 'creep' on the program pulses. So you may START with the loco well away from the gaps but suddenly - poof - it bridges the gaps. The dead section makes this about as impossible as can be.
Okay, I see all the benefits of having the dp/dt switch and will probably retrofit what I have at home as well as at the club. However, for whatever it might be worth, I did call NCE this morning and spoke to them about this back feeding issue. The gentleman I spoke with said that the outputs of the programming portion of the command station were protected from being back fed. So, it appears that they have protected us from our own failures.
maxman Okay, I see all the benefits of having the dp/dt switch and will probably retrofit what I have at home as well as at the club. However, for whatever it might be worth, I did call NCE this morning and spoke to them about this back feeding issue. The gentleman I spoke with said that the outputs of the programming portion of the command station were protected from being back fed. So, it appears that they have protected us from our own failures.
Occassionally you'll see a tendancy in these forums to over-engineer solutions. While technically viable, they sometimes add complexity and cost. I am glad NCE cleared this up for you.
OK, so maybe you won't break anything - how about the OTHER thing that can happen if the gaps are bridged - namely programming every loco on the track? I don't think totally isolating the programmign track is overengineering at all. The SIMPLEST solution is to have the program track completely removed from the layout, but that requires you to pick up and move every loco for programming. I didn't do the 4PDT switch thing, I just had one set of gaps and a plain DPDT switch - at the very minum you have to have the DPDT, unless again you don't mind picking up or pushing your locos off the program track. You absolutely positively CAN NOT connect the program track outputs and the main track outputs to the same piece of track and expect it to work. It may not damage the command station, but it won't program, either.
rrinker OK, so maybe you won't break anything - how about the OTHER thing that can happen if the gaps are bridged - namely programming every loco on the track?
Randy:
I agree with you completely on this point. But that was not my original question. Someone earlier on brought up the command station damage issue, and that was my immediate concern.
I'm pretty sure that I can find a way to re-program every other locomotive on the railroad even without jumping the gaps separating the programming track from everything else. But doing that only shows that I can be dumb. My concern was that it was possible to damage the command station even if I had the thing wired up as shown in the instructions. That would mean that someone else was dumb.
My program track power is connected by a switch that throws with the track switch that leads to the program track. If the track switch is thrown, which would route the engine onto the program track, the the track outputs are connected to the program track. If the track switch is closed, so that trains will bypass the program track, then the program outputs are connected to the program track.
I just run the engine onto the program track and close the switch. Program the engine, throw the switch and back it back out onto the main line. I designed them that way because I originally stored DC engines on them, but I no longer have any DC engines so I converted them from unpowered to program when the switch is closed. One for Digitrax Program outputs and one for the PR3.
Dave
Lackawanna Route of the Phoebe Snow
Phoebe Vet My program track power is connected by a switch that throws with the track switch that leads to the program track. If the track switch is thrown, which would route the engine onto the program track, the the track outputs are connected to the program track. If the track switch is closed, so that trains will bypass the program track, then the program outputs are connected to the program track. I just run the engine onto the program track and close the switch. Program the engine, throw the switch and back it back out onto the main line. I designed them that way because I originally stored DC engines on them, but I no longer have any DC engines so I converted them from unpowered to program when the switch is closed. One for Digitrax Program outputs and one for the PR3.
Yep. That's basically how I do it (or I use the human forklift approach for moving new locomotives onto the programming track)