to the forum. I'm afraid I have forgotten more about DC than I ever knew, but by responding to your post, it will appear higher up and get noticed by those that know.
As a loco moves from one circle to the next, it is going have the front half controlled by one controller and the back half controlled by another. If the controllers aren't set exactly the same, it seems to me there would be a lurch as it crosses over to the next oval.
In a block, only one throttle has control at a time. To get a train from the inner oval to the outer, imagine multiple short blocks. As the train moves from inner circle A to outer circle D, I would have one throttle, progressively control each block, rather than jump from throttle to throttle to control the train. I suppose this could be done with a rotary switch. As the famous model railroader, Billy Shakespeare said, "If Henry is full of it, we will find out anon."
In DCC, this is positively simple. You tell the train where to go and it goes.
PS your intial several posts are moderated, meaning there will be a delay from the time you post to the time anyone sees it.
Henry
COB Potomac & Northern
Shenandoah Valley
I would suggest that You read the info contained in the link I will provide so that You can better understand how to accomplish what You would like to do with Your idea. Spend special attention to the title paragraph labeled Block control wiring to help you: Then when needing help it will be easier for someone to help You.
http://www.building-your-model-railroad.com/model-railroad-wiring.html
To The Forums....
Take Care!
Frank
RR_MelIf one the opposing power packs is reversed you can easily double the voltage at the junction, not good! That will let the smoke out and you can’t put it back.
Should not be any smoke.......internal circuit breaker in power packs will trip. Even a trainset power pack has an internal circuit breaker.
DC user since 1950......
zstripe RR_Mel If one the opposing power packs is reversed you can easily double the voltage at the junction, not good! That will let the smoke out and you can’t put it back. Should not be any smoke.......internal circuit breaker in power packs will trip. Even a trainset power pack has an internal circuit breaker. DC user since 1950...... Take Care! Frank
RR_Mel If one the opposing power packs is reversed you can easily double the voltage at the junction, not good! That will let the smoke out and you can’t put it back.
Mel,
I guess anything is possible.........but I have been using 28/30 gauge wire on many power arrangements, 12, 24, 28volts, the wire is rated for 36volts at 6A. I don't go past 4A with any of it though........just saying! I'm sure the motor would get a little warm from 24v, but once the engine is out of the block, it would go back down to 12 volts and run fine....it would happen very fast. The only big problem would be if they were different polarities......then a decent power pack would shut down, if only to protect itself..........I have had that happen to Me, with My control master 20's. It was purely a feeder miswire, that I created without knowing it.
The way I see this, you need to isolate both rails. You have 3 seperate lay outs, so to speak, each with it's own power pack, and the connection between them must be insulated, both rails. You don't want any spot where the track is powered by two power packs.
So, with all powerpacks set at as close to the same speed, as your loco moves from the inner to the middle, as it crosses the isolated turnout, the front half will be picked up by the middle track power pack, and the back half will be powered by the inner power pack, until it clears the turnout, and is in complete control of the middle power pack.
I don't see a problem with this.
Henry's explaination makes complete sense, but your going to be doing this, kind of block to block thing, as you move from one track to the other. The inner circle being one block, and middle the next, and so on.
Frank's link provides some great go-to info, with returns loops, wye's, etc. It's a great DC reference.
Mike.
My You Tube
So if I isolate the track (on both rails) at all turnout intersections by using plastic connectors, and make certain the speed and polarity is the same for all four track routes, then there should be no issues as the locomotive passes over the junction of the two turnouts? Is there any chance that the locomotive would recieve 24 volts as it crosses the gap between the two track routes due to the two seperate power supplys?
Thank you Frank for your help. I will read the information you referenced.
I'm not questioning Mel's eclectrical knowledge, but this doesn't seem any different to me, that a train moving from one block to another.
I didn't envision a 24 volt short either.
I get your illustration, and if the power packs were connected opposite the way you have, yes, KABOOM
Both power packs have to have the polarity the same.
The OP will have to make sure, by testing a loco on each track, and make sure the power packs all go the same direction, and the loco moves in the same direction on all three loops.
I thought I was asking a fairly simple question, obviously I was not. If I want to run two trains, both going counterclock wise, and changing occasionally to a longer line, on a DC only setup, with only one train on a particular line, it seems isolation of each concentric route, and each with it's own power pack is the easiest way to set things up. I understand that the polarity must be cosistent between controllers and the speeds should be as close as possible for the switch from one track route to the next. Frankly I do not see a problem with this method of operation. Setup this way I should be able to run two trains in opposite directions with one train running only on the two outer track lines and another running only on the inner two tracks. Maybe one day down the line I will understand the finer points (i.e. Blocks) that you guys are worried about but for now I am going to try and keep it simple and pay attention to what I am doing so as to not smoke my loco's.
As long as You keep the polaritys the same when crossing into another power packs territory, You will not have any problem's. I've been doing it for yrs. You won't have 24 volts in the transition......maybe 12volts......unless You have both power packs set at Full throttle, in which case, it would probably be more than 24v, some packs put out more than 12 volts at full throttle. My current layout is DC 3-CAB block control, with 3 MRC CM20's, now that is enough power to smoke a boxcar.......have not had any problem's, other than My crossing a feeder, in which case the power source shut down. Layout has been up and running since 1980. I have since downsized it to a 2-cab system. The layout was just too big for one person, but I had built it in sections so I was able to shorten it and gave the sections to My Grandson's for their basement layout still in construction. It was 12 1/2 x 40' x 12 1/2' in My attic.......now it is roughly half that size. It is two rail insulated, with block control. I do run DCC on it once in awhile......no big deal....it works for My needs.........
This pic' (1959) is in My Parents basement when I was 17yrs. old, that is the last time I used common rail wiring, one rail insulated: I powered that with a MRC Golden Tri-Pack, that was 3 separate power packs in one case.......still have it. Track was Atlas brass hand laid code 100.
Watchman54 I thought I was asking a fairly simple question, obviously I was not. If I want to run two trains, both going counterclock wise, and changing occasionally to a longer line, on a DC only setup, with only one train on a particular line, it seems isolation of each concentric route, and each with it's own power pack is the easiest way to set things up. I understand that the polarity must be cosistent between controllers and the speeds should be as close as possible for the switch from one track route to the next. Frankly I do not see a problem with this method of operation. Setup this way I should be able to run two trains in opposite directions with one train running only on the two outer track lines and another running only on the inner two tracks. Maybe one day down the line I will understand the finer points (i.e. Blocks) that you guys are worried about but for now I am going to try and keep it simple and pay attention to what I am doing so as to not smoke my loco's.
Rich
Alton Junction
To put it plain and simple.......On a DC layout the engine is controlled by the Variable DC output to the track, which is from 0 to around 13volts DC. There is no constant 12volts to the track, unless You turn the throttle all the way up, You would have to do that to both throttles to even get close to 24volts.
In DCC the voltage is constant to the tracks roughly 13.5 + The decoder in the engine controls the speed/start/stop/lights etc. In that scenario if you had two different power districts set-up and one was a different polarity than the other, when engine crossed into the gapped power districts, you then would have a problem, in which case the DCC base should shut down.
Bye, Bye........
RR_MelEven at half throttle I would never connect two power packs together with reversed voltage, not much difference than putting a couple of AA batteries shorting together as far as I’m concerned.
I believe You are missing the point......No one said that they are connecting two separate power packs together with opposite polarity. The point being, is to make sure that they ARE NOT of opposite polarity, when crossing into one another regardless of voltage setting........
Thank you Frank. Very helpful. At least I know I am not completely crazy. Maybe one day I will spring for DCC and all ths will be mute but for now DC is good for me. Besides I have to sneek up on those kind of expenditures or my wife of 45 years will not be happy. She has already threatened to take my ebay privilages away.
Would love to go all DCC but the added cost is prohibitive for now. I will switch over to DCC when my wife is fully onboard with model railroading. I would have prefered HO or O rather than N but space is a concern and I want more than what I had in the past with HO. My current layout is based on the old west and the locos are a little small for DCC.
Watchman54 Thank you Frank. Very helpful. At least I know I am not completely crazy. Maybe one day I will spring for DCC and all ths will be mute but for now DC is good for me. Besides I have to sneek up on those kind of expenditures or my wife of 45 years will not be happy. She has already threatened to take my ebay privilages away.
I run three cab, block control, with Crest wireless throttles,
Frequently some one will try to enter a block not turned to his cab. One of three things happen:
i) next block same polarity, different throttle, train is being controlled by other throttle.
2) next block is off, the train stops, until block switch is changed.
3) Reversed polarity the engine osoclates about 1/2 inch until block switch is changed.
No smoke, damage, etc in 16 years.
Dave