TomDiehl wrote: concretelackey wrote: TomDiehl wrote: concretelackey wrote: cacole wrote:In theory, your idea should work as long as you are absolutely certain that only one of the power packs is on at any one time. The biggest problem encountered would be if they should inadvertently both be on but set to opposite polarity.Did not think this thru the whole way yet.....What about using 2 three way light switches? The same ones you use to operate a single light from 2 locations. Have a switch and receptacle at each power pack. If pack A is enegized this automatically kills pack B and vise versa.OK, I'm not following what you're trying to say here. I've wired this type switch pair and the two switches will apply or remove power to a single load, be it a light or a power pack. They're basically a SPDT switch with a 3 conductor wire running between them. How you'd wire them to turn on one while turning off the other is a mystery.I made that post using my limited knowledge of basic electrical design thinking that when the switch that powers pack A is on, pack B is automatically turned off. Flip on pack B's switch and pack A loses power. Perhaps the 2 switch/one light scenario won't work but there should be a relatively simple solution to this.Forgive my lack of knowledgeNo need to appologize, I was just hoping to add another tidbit of info to my wiring knowldege. I once had to show an electrician how to wire a duplex outlet so only one of the sockets were controlled by the wall switch.
concretelackey wrote: TomDiehl wrote: concretelackey wrote: cacole wrote:In theory, your idea should work as long as you are absolutely certain that only one of the power packs is on at any one time. The biggest problem encountered would be if they should inadvertently both be on but set to opposite polarity.Did not think this thru the whole way yet.....What about using 2 three way light switches? The same ones you use to operate a single light from 2 locations. Have a switch and receptacle at each power pack. If pack A is enegized this automatically kills pack B and vise versa.OK, I'm not following what you're trying to say here. I've wired this type switch pair and the two switches will apply or remove power to a single load, be it a light or a power pack. They're basically a SPDT switch with a 3 conductor wire running between them. How you'd wire them to turn on one while turning off the other is a mystery.I made that post using my limited knowledge of basic electrical design thinking that when the switch that powers pack A is on, pack B is automatically turned off. Flip on pack B's switch and pack A loses power. Perhaps the 2 switch/one light scenario won't work but there should be a relatively simple solution to this.Forgive my lack of knowledge
TomDiehl wrote: concretelackey wrote: cacole wrote:In theory, your idea should work as long as you are absolutely certain that only one of the power packs is on at any one time. The biggest problem encountered would be if they should inadvertently both be on but set to opposite polarity.Did not think this thru the whole way yet.....What about using 2 three way light switches? The same ones you use to operate a single light from 2 locations. Have a switch and receptacle at each power pack. If pack A is enegized this automatically kills pack B and vise versa.OK, I'm not following what you're trying to say here. I've wired this type switch pair and the two switches will apply or remove power to a single load, be it a light or a power pack. They're basically a SPDT switch with a 3 conductor wire running between them. How you'd wire them to turn on one while turning off the other is a mystery.
concretelackey wrote: cacole wrote:In theory, your idea should work as long as you are absolutely certain that only one of the power packs is on at any one time. The biggest problem encountered would be if they should inadvertently both be on but set to opposite polarity.Did not think this thru the whole way yet.....What about using 2 three way light switches? The same ones you use to operate a single light from 2 locations. Have a switch and receptacle at each power pack. If pack A is enegized this automatically kills pack B and vise versa.
cacole wrote:In theory, your idea should work as long as you are absolutely certain that only one of the power packs is on at any one time. The biggest problem encountered would be if they should inadvertently both be on but set to opposite polarity.
Did not think this thru the whole way yet.....What about using 2 three way light switches? The same ones you use to operate a single light from 2 locations. Have a switch and receptacle at each power pack. If pack A is enegized this automatically kills pack B and vise versa.
OK, I'm not following what you're trying to say here. I've wired this type switch pair and the two switches will apply or remove power to a single load, be it a light or a power pack. They're basically a SPDT switch with a 3 conductor wire running between them. How you'd wire them to turn on one while turning off the other is a mystery.
I made that post using my limited knowledge of basic electrical design thinking that when the switch that powers pack A is on, pack B is automatically turned off. Flip on pack B's switch and pack A loses power. Perhaps the 2 switch/one light scenario won't work but there should be a relatively simple solution to this.
Forgive my lack of knowledge
No need to appologize, I was just hoping to add another tidbit of info to my wiring knowldege. I once had to show an electrician how to wire a duplex outlet so only one of the sockets were controlled by the wall switch.
It would be nice for future reference to see a diagram of the OP's solution though.
BlueHillsCPR wrote: Phoebe Vet wrote: If you use two SPDT switches you are left with the possibility of having only one switch thrown. Maybe I am confused but I don't think you are seeing where I was going with my suggestion. I've got to get around to posting images here! Then I could post a wiring diagram that would clarify what I was suggesting. After thinking about it, one SPDT switch should work for what I had in mind. Anyway. it doesn't really matter. The DPDT switch will work admirably providing absolute isolation of one pack from the other.
Phoebe Vet wrote: If you use two SPDT switches you are left with the possibility of having only one switch thrown.
If you use two SPDT switches you are left with the possibility of having only one switch thrown.
Maybe I am confused but I don't think you are seeing where I was going with my suggestion. I've got to get around to posting images here! Then I could post a wiring diagram that would clarify what I was suggesting. After thinking about it, one SPDT switch should work for what I had in mind.
Anyway. it doesn't really matter. The DPDT switch will work admirably providing absolute isolation of one pack from the other.
My only point is that before you connect power pack B to a block, you need to completely disconnect power pack A. With a switch, that means disconnecting both leads to the block.
If you don't want to invest in a second power pack, you can use jacks at both locations, and just unplug and move the power pack to the other location when needed.
There is no need to turn off or cut the power to the pack unless it will be disconnected from the track for a long time.
Dave
Lackawanna Route of the Phoebe Snow
What you are really appear to be looking for is block control at both a central and a local panel. Ideally, you would have some form of interlock so that the local selection over-rides the central panel, or the local panel is only active when selected to be so at the central panel. This is not a new science, but the art seems to have disappeared from DC block control wiring, as does the use of more than 2 cabs.
The forum member who is really expert in this - Chuck, goes by the handle of tomikawaTT. Maybe you could get him to chime in. He uses a version of Ed Ravenscroft's MZL control system. MZL stood for Master, Zone, and Local, and was published in Model Railroader in the 1960s I believe. There was a simple form of master and local panels used on the Ma and Pa Model Railroader project layout in 1965. I no longer have those magazine issues immediately at hand. I wish I could recall in detail how the wiring was done, by my memory is fading.
In general, there are a couple of ways to go where you want.
One is to use only local panels. Each block is controlled only from a local panel. You run a pair of wires for each cab to each local panel, which then assigns the block to the appropriate cab. Cabs can be anywhere in this scheme, but can still control anywhere on the layout. Disadvantage is that you have to roam the layout to change the block toggle settings. This would be the normal operating mode for larger layouts using DC walk-around controls until the arrival of DCC. The walk-around controls added throttle buses to the wiring so that you could have multiple plug-in jacks for throttles, and be able to follow your train. At its most elaborate, transistor throttles with memory allowed the train to keep running while you switched throttle jacks.
The next layer is to add a central panel to the local panels. The central panel would have a toggle for each local panel that decided which panel had control of block selection - the central or the local. This scheme favors central panel operations, because you have to select the local panel from the central panel. The selection toggle would determine the routing of cab power to the panels, and sits in front of either bank of block toggles. If common rail/return wiring is used, a DPDT is sufficient for the panel selection toggle. If common rail is not used, a 4PDT rotary or toggle would be ideal, or a separate DPDT would be used for each throttle. The latter case of multiple toggles lends itself to confusion, with the possibility of one toggle selecting the master panel, and the other selecting local.
In the OP's case, two local panels, or one central and one local are all that are needed.
Beyond this, my head hurts, and I recommend getting a hold of the articles I cited for details.
yours in not remembering how to wire
Fred W
Phoebe Vet wrote:If you use two SPDT switches you are left with the possibility of having only one switch thrown.
ndbprr wrote:In a way I am being picky but we don't run trains with transformers. They are strictly AC devices. We use rectifiers that convert AC to DC. So the proper term is rectifer or power pack as they are commonly known in the hobby. Now a power pack does have a transformer inside but it provides the rectifer with the proper stepped down AC voltage.
Not to hijack this thread too far off topic, but.
Since most, if not all power packs supply both AC and DC doesn't the pack actually contain a transformer to drop the line voltage to a useable level and a rectifier for the DC. Now I'm not sure if the DC is 1/2 wave rectified or full wave but isn't it only the dc that requires a rectifier? In any case calling the power pack a transformer is not entirely incorrect as the AC voltage is simply transformed to a lower value and is not rectified even though the DC voltage is. In any event, yeah, you were being picky.
BigG wrote: I think the safest way is to use a DPDT switch with one powerpack wired to the leftmost switch contacts, and the other pack to the rightmost contacts. The track wires for the faraway section go to the common (usually centre) set. This gives you full isolation of 1 pack from the other. Have fun. George
I think the safest way is to use a DPDT switch with one powerpack wired to the leftmost switch contacts, and the other pack to the rightmost contacts. The track wires for the faraway section go to the common (usually centre) set. This gives you full isolation of 1 pack from the other.
Have fun. George
THIS is absolutely the only way to go. If you use two SPDT switches you are left with the possibility of having only one switch thrown.
It is essential that only one power pack be CONNECTED to the track at a time. Turned off is not sufficient.
TomDiehl wrote: roypea wrote: Thank you and the others for your helpful replys, yes I think the DPDT switch you've described is the ticket and should provide the powerpack isolation needed. I'll keep watching but if you don't hear anymore it either worked or I burned the place down, LOL.RoyPeaWhat BigG described above is what is commonly called cab control. Each power pack (so I won't get corrected on terminology) would be considered a "cab," At a minimum, it has speed and direction control, just like in the cab of a locomotive, which is where the name comes from. In a standard setup, the cabs would be located side-by-side, with the toggle selecting one or the other to control a given block, but there's no reason one of them couldn't be located at the opposite side of the layout for the operator's convenience. You'll just need a longer hookup wire.
roypea wrote: Thank you and the others for your helpful replys, yes I think the DPDT switch you've described is the ticket and should provide the powerpack isolation needed. I'll keep watching but if you don't hear anymore it either worked or I burned the place down, LOL.RoyPea
Thank you and the others for your helpful replys, yes I think the DPDT switch you've described is the ticket and should provide the powerpack isolation needed. I'll keep watching but if you don't hear anymore it either worked or I burned the place down, LOL.
RoyPea
What BigG described above is what is commonly called cab control. Each power pack (so I won't get corrected on terminology) would be considered a "cab," At a minimum, it has speed and direction control, just like in the cab of a locomotive, which is where the name comes from. In a standard setup, the cabs would be located side-by-side, with the toggle selecting one or the other to control a given block, but there's no reason one of them couldn't be located at the opposite side of the layout for the operator's convenience. You'll just need a longer hookup wire.
All that being said... here's my ...
The "cab control" is the answer, but still limites true "control" to the main side of the layout. Example, you have a derail, you walk around, fix it, go to try it out, only you find you forgot to flip the switch.........so you go back around and fire it up from the wrong side anyway...
I think ConcreteLackey was on to the best senerio....use 2 three way light switches to alternate AC power to your "power packs". That way you can turn on either one from either side, but NEVER both at the same time.
BlueHillsCPR wrote: concretelackey wrote:What about using 2 three way light switches? The same ones you use to operate a single light from 2 locations. Have a switch and receptacle at each power pack. If pack A is enegized this automatically kills pack B and vise versa.Well that was sort of what I was suggesting in my earlier post about using SPDT switches. I don't think he needs to switch the line voltage to the packs just which pack is powering the block. larak wrote:Preferable to use 5 amp mini toggles and just switch the DC from one to the other.Do not connect two packs directly in parallel (even if turned "off"). Depending on design, the output impedance of each can act as a load on the other, possibly to no detriment, possibly with disasterous results.Karl. Yes the mini toggles is what I had in mind originally. to connecting directly in parallel!
concretelackey wrote:What about using 2 three way light switches? The same ones you use to operate a single light from 2 locations. Have a switch and receptacle at each power pack. If pack A is enegized this automatically kills pack B and vise versa.
Well that was sort of what I was suggesting in my earlier post about using SPDT switches. I don't think he needs to switch the line voltage to the packs just which pack is powering the block.
larak wrote:Preferable to use 5 amp mini toggles and just switch the DC from one to the other.Do not connect two packs directly in parallel (even if turned "off"). Depending on design, the output impedance of each can act as a load on the other, possibly to no detriment, possibly with disasterous results.Karl.
Do not connect two packs directly in parallel (even if turned "off"). Depending on design, the output impedance of each can act as a load on the other, possibly to no detriment, possibly with disasterous results.
Karl.
Yes the mini toggles is what I had in mind originally.
to connecting directly in parallel!
Yes! Exactly what he said!
roypea wrote:Can you define, "in a way" sounds like you've kinda' gone over the line a bit, but thanks for the reply, albeit useless.
He was politely correcting us on the terminoligy.
Preferable to use 5 amp mini toggles and just switch the DC from one to the other.
The mind is like a parachute. It works better when it's open. www.stremy.net
I am still DC on this little layout, but from time to time, it would be helpful to control a loco from the opposite side of the layout, across from the main console.
I'm HO, DC and using dual Cab control of an 8 block setup (includes two small yards, and two passing sidings.) As might be expected (my motto is "if there is an easy way, I can find a way around it!") most of the derailments that DO occur are on the opposite side of the layout, and it would be nifty if I could turn off the transformer, fix the problem and verify it by running the train.
I have an unused dual control transformer, an MRC 2800 or something like that, Is it possible to hook it and the standard controller up parallel and set the MRC on the far, offending side of the layout. The habit I'd try to maintain is to shut off power on the near side transformer, before powering on the far side transformer, and vice-versa.
I know there are remotes out there to buy or build (http://www.awrr.com/throttle.html)and I may actually try one, but right now I have the spare and the need.
Thanks for your help and continued Happy Holidays.
Roypea