fwright wrote: Hope you don't mind me sharing the idea with others, with the credit going to you, of course.
If you or any member of your team is captured, we will, of course, disavow all knowledge...
I like the light bulb idea. In fact, it could be used to control working signal lights, wiring both the red and green bulbs so that only the appropriate one would be turned on for each path. That way, if you forget to throw the switch and the train stops, well, the engineer was just obeying the signals.
It takes an iron man to play with a toy iron horse.
MisterBeasley wrote:Well, there is a way, but it's a kludge. And if you think "stretching the zero bit" is "a stretch," wait 'til you see this one:Instead of wiring the loop through the reverser, wire the main through the reverser. Wire the loop through a DPDT, although this solves a different problem, and you may end up not having to use it.The DPDT will control the direction of the DC loco in the loop. If you always run through the loop the same way, then you won't need this, but adding the DPDT will give you the option of choosing the direction through the loop.By wiring the main through the reverser, you will force the main to flip over when the engine comes out of the other end of the loop, thus maintaining its direction.Now, why don't we normally do this? Why is the "correct" way to wire a reverser to wire it to the loop, and not the main? First, you are limited to 1 reverse loop if you do it this way. Otherwise, you have to guarantee that you're not crossing the isolaters of two loops at the same time, which would cause a short. Second, some (most? all?) reversers can't handle the full 5 or 8 amps of the beefier DCC systems and boosters. (I think mine is spec'd at 2 amps.) So, while that's fine for a single engine working in a reverse loop, you wouldn't want to limit your whole layout to only 2 amps if your system supports more.
Well, there is a way, but it's a kludge. And if you think "stretching the zero bit" is "a stretch," wait 'til you see this one:
Instead of wiring the loop through the reverser, wire the main through the reverser. Wire the loop through a DPDT, although this solves a different problem, and you may end up not having to use it.
The DPDT will control the direction of the DC loco in the loop. If you always run through the loop the same way, then you won't need this, but adding the DPDT will give you the option of choosing the direction through the loop.
By wiring the main through the reverser, you will force the main to flip over when the engine comes out of the other end of the loop, thus maintaining its direction.
Now, why don't we normally do this? Why is the "correct" way to wire a reverser to wire it to the loop, and not the main? First, you are limited to 1 reverse loop if you do it this way. Otherwise, you have to guarantee that you're not crossing the isolaters of two loops at the same time, which would cause a short. Second, some (most? all?) reversers can't handle the full 5 or 8 amps of the beefier DCC systems and boosters. (I think mine is spec'd at 2 amps.) So, while that's fine for a single engine working in a reverse loop, you wouldn't want to limit your whole layout to only 2 amps if your system supports more.
Sheer genius, Mister Beasley.
It may be a kludge, but it's also a workable way to use an auto-reverser for straight DC. The only catch is that you would have to match the polarities for entry into the reversing section manually. If not matched, the auto-reverser and reversing section will create the match by causing the train to reverse direction as it hits the reversing section entry gaps. But that's probably no worse than the situation with 2 direction toggles downstream of the throttle. And you can use a lightbulb or LED wired across the gaps to indicate whether the polarity is aligned.
The current limitation is probably more than sufficient for normal DC use.
Hope you don't mind me sharing the idea with others, with the credit going to you, of course.
Fred W
KingConrail76 wrote: MisterBeasley wrote:Yes, you can run a DC engine as Engine Zero on some DCC systems. However, you're going to have a problem with the reverse loop. Auto-reversers do not work with DC engines, even on those DCC systems which support the Engine Zero option. The problem is that auto-reversers work by flipping the polarity of the controlled track section. When you do this, DCC engines are unaffected, but DC engines will immediately reverse direction. So, they'll get to the gap where the auto-reverser flips things, and try to go back the other way.Mr.B,.....With that being the case, could the reverse section be wired with DPDT toggle and, for the DC loco, be reversed in the traditional DC manor of changing polarity and Loco direction (on the throttle) together? Or in the OPr's case is the only solution to go with a DCC loco in replacement of the DC he has?My curiousity has been peaked, but my time for experimentation is limited....
MisterBeasley wrote:Yes, you can run a DC engine as Engine Zero on some DCC systems. However, you're going to have a problem with the reverse loop. Auto-reversers do not work with DC engines, even on those DCC systems which support the Engine Zero option. The problem is that auto-reversers work by flipping the polarity of the controlled track section. When you do this, DCC engines are unaffected, but DC engines will immediately reverse direction. So, they'll get to the gap where the auto-reverser flips things, and try to go back the other way.
Mr.B,
.....With that being the case, could the reverse section be wired with DPDT toggle and, for the DC loco, be reversed in the traditional DC manor of changing polarity and Loco direction (on the throttle) together? Or in the OPr's case is the only solution to go with a DCC loco in replacement of the DC he has?
My curiousity has been peaked, but my time for experimentation is limited....
I'm going to use the term polarity with regard to DCC because it is easy to understand, even though not technically correct. The principle is the same.
The "zero stretching" used by some DCC systems to run a single DC locomotive is polarity-sensitive, just like normal DC. To reverse the DC locmotive running on DCC zero-stretching the polarity is changed at the throttle.
A reversing section to run a DC locomotive normally has two DPDT toggles that are independent of the throttle. One DPDT controls polarity (direction) in the reversing section, the other controls polarity on the rest of the layout (main). When the train is fully contained in the reversing section, the main direction toggle is thrown to change the polarity of the rest of the layout to match the reversing section as the train exits.
In DCC, the polarity of the reversing section is changed to match while the train is entering and/or exiting the reversing section. Since polarity does not control direction in DCC, switching polarity does not affect the train. Auto-reversers sense the short circuit as the locomotive crosses the gaps into/out of the reversing section, and instantly switch the polarity of the DCC before the circuit breaker can trip.
The two schemes for reversing sections are not compatible with each other. To use a reversing section with zero stretching requires the auto-reversers to be switched out of the circuits and the independent DPDT direction toggles used.
I don't know about you, but my memory isn't nearly good enough to remember that when I use a reversing section with a locomotive on zero-stretching I have to manually turn off the auto-reverser and flip direction toggles! The rest of the time I leave direction toggles alone, and let the auto-reverser do its thing. I have enough trouble remembering to throw turnouts correctly before the train arrives as it is!
Given that many DC locomotives don't run well on zero-stretching anyway, and should never be left sitting still for any length of time on DCC, I strongly recommend against the practice where reversing sections are present. If you need to run both DC and DCC, my recommendation is to wire for DC block control, and switch in the DCC unit for one of the DC power packs. Even then, it should be all DC ops or DCC ops, not both at the same time. DC locomotives get removed for DCC operations, and older DCC decoders (decoders that are not dual mode) must be removed for DC operation.
No matter how you slice and dice it, it's a lot easier (and cheaper if there's only a few) just to convert the remaining locos to DCC.
my thoughts, your choices
Thanks for the heads up. I have very few DC locos, and they were planned to be used on a seperate area (DC controlled Terminal RR or Lg. Industry) of the layout, so I have never run them thru my reversing section to see the results you shared above.
With that being the case, could the reverse section be wired with DPDT toggle and, for the DC loco, be reversed in the traditional DC manor of changing polarity and Loco direction (on the throttle) together? Or in the OPr's case is the only solution to go with a DCC loco in replacement of the DC he has?
My curiousity has been peaked, but my time for experimentation is limited.
Maybe I missed it, but I don't recall seeing you state what for DCC controller you are using. And this may apply to other brands as well, but I know with Digitrax, you can run a DC engine as Address 0 (Zero). It sounds as though you only have (1) DC engine that has such Sentimental Value (without a doubt, the most valuable of valuables), so this might be your simplest solution.
As for all the automated Track Work, Just do it as you would for a "typical" DCC installation.
I myself am in the planning stages of my second layout with a revising section in it and while I plan to convert to DCC control some day I have designed a wiring diagram to address this matter and have posted it to my web site http://devinville-rr.mysite.com/ if you think that it may help. The track power (in the reversing section) is controlled by toggle switches at four different locations on the layout with four LED's that help by telling you if the system is set correctly before crossing the gap into the reversing section or before leaving it. As to marking the gap between the reversing section and the rest of the layout you can have it at a road crossing or simple mark it with a small spot of white sand in the ballast.
Johnny_reb
Johnnny_reb Once a word is spoken it can not be unspoken!
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I also like Mr. Beasley's idea. I did some research and the Alaska Railroad has a few different locomotives such as the SD70, GP40-2, and a GP38-2. The Atlas GP38 is more of the color scheme that I'm after and I also like the Idea of removing the motor in the old Bachmann.
I had a hard time finding any of the Atlas N diesels . They were discontinued at every place that carried them, but I did locate one.
Jeff But it's a dry heat!
Atlas makes an N-scale GP40 in Alaska, with or without a decoder already installed. It's not the same color scheme as the Bachmann, but it's close. Or, you could go with a different model of engine if you want to stick to the Alaska Railroad theme.
From the price of the Bachmann engine I found online, it's not going to be a good performer in the long run. You may end up replacing it anyway. So, upgrading to an Atlas now will give you both instant gratification and more enjoyment down the road.
As for what to do with the Bachmann afterwards? Well, if it were mine, I would remove the motor and gears, and replace them with a sound-only decoder and speaker. Then you could run the pair of engines together and have both good performance and sound. If your son hears a whistle on that YouTube video, it will bring a smile to his face, even in Iraq.
I have the Bachmann McKinley Explorer N Scale Train Set. The Bachmann train is not of very good quality, but my son bought it for me after I booked an actual Alaskan trip to ride the McKinley Explorer into Denali National Park. He is currently driving an Army fuel truck in Iraq and I really would like to get it up and running for when ever he gets home. I might even make a video and post it on ‘YouTube' just in case he ever gets on the Internet.
Quote: "I realy like my N-scale DC train and I can't convert to DCC." Unquote.
I may not be as familiar with loco conversions as others, but I've never heard of a locomotive that COULDN'T be converted to DCC. Might take a tremendous amount of work, but it should be possible.
What locomotive do you have? Maybe someone on the forum can suggest how to install a decoder in it. Then you will have all-DCC and not have to worry about switching back and forth between DC and DCC. (And, as others have mentioned, switching back and forth from DC to DCC is INVITING disaster! It would cost more to repair the smoked items than it would to have a decoder professionally installed in your loco!)
Good luck with your layout.
Darrell, quiet...for now
Sorry to spoil your idea, but a DCC auto-reverse module works only on DCC. All of the other ideas you postulate about using all manner of detectors, etc., sounds like a wiring nightmare and a sure-fire way to release the magic smoke from locomotive motors, DCC decoders, and power supplies. The first time you forget to throw a toggle switch everything will come to a screeching halt and possibly never run again.
A good DCC system with auto-reverse modules that will accomplish everything you are proposing would not cost as much as the electronics gizmos necessary to run both DC and DCC.
Sorry, I'm going to rain on your parade. Dynamic switching between DC and DCC is not a good idea at all. Sooner or later, you're going to end up throwing the automated switch while the gap is bridged by another locomotive, or a metal-wheeled truck on a piece of rolling stock. There's a good chance that something will smoke.
I'm going to recommend going to all DCC. Unless you have a huge locomotive roster, you'll find this is cheaper than all the proposed circuitry, and you'll be happier in the long run.
I have two DDC Mainlines with a Double Reverse Loop off one of the main lines. The Double Reverse Loop is separated into 5 blocks. I'm using Atlas N Code 80 Remote Switches. I want to run a DC train through the loops automatically as if it where just one continuous loop and also be able to change from DC to DCC to allow trains from main DCC line to pass-through or turn around in one of the loops. (I have a drawing of the layout, but I don't know how to attach it.)
To accomplish this, I'm thinking of using a Circuitron AR-1 switch combined with DT-4 Rolling Stock Detector and (2) TC-1 Turnout Controls to operate the double reverse loop with the Non-DCC train. When a DCC train approaches from the main line toward the double reverse loop, a second DT-4 Detector activates 2 Tortoise Switch Machines on the main line to open the loop with DC train and switch the other blocks and/or Turnout to DCC.
Does anyone know of a better system capable of Automatic Double Reverse Loop Control with a Detection Circuit and Turnout Control for DC?
After drawing out my plan I realized that I'm over $200 in electrical parts and I think I'm also going to need another detection device to stop the DCC train if the DC train is in the wrong loop. I realy like my N-scale DC train and I can't convert to DCC. I'm new to DCC and don't know much, but I think I'm still going tp need the same controls even it was all DCC.