Post by: SD90 on August 23, 2016, 04:46:27 PM
The layout is basically a point to point around the wall triple deck, with a helix going from level 1 to 2 and 2 to 3. (There will be an option on each level for continuos running.) The basement is 31'x30' with a 7'x8' bump out where the helix will be. There will be 500' of mainline run, will 1 Railpro power supply be enough, or should I get 2?
If I place the power supply in a corner, and have 3 bus lines going out (1 for each level) in each direction they will be about 60' long each, plus the helix. I'm planning on using 14 gauge bus wire.
If I did use 2 oder supplies, would I need to insulate the rail joints where they meet?
Post by: nodcc4me on August 23, 2016, 06:28:45 PM
That's going to be quite a layout. Waiting for pictures. :)
Post by: SD90 on August 23, 2016, 06:48:38 PM
I'd just have to insulate one wire, not both?
Post by: nodcc4me on August 23, 2016, 07:02:57 PM
Post by: Alan on August 23, 2016, 07:08:42 PM
Post by: Alan on August 23, 2016, 07:11:19 PM
Post by: Alan on August 23, 2016, 07:34:29 PM
http://www.ebay.com/itm/5A-15V-AC-Adapter-Power-Supply-Charger-Fr-Toshiba-Satellite-Portege-Tecra-Laptop-/321835366443?var=&hash=item4aeee1f82b:m:mQx8MHuKXAaraAOtsbOdPmQ (http://www.ebay.com/itm/5A-15V-AC-Adapter-Power-Supply-Charger-Fr-Toshiba-Satellite-Portege-Tecra-Laptop-/321835366443?var=&hash=item4aeee1f82b:m:mQx8MHuKXAaraAOtsbOdPmQ)
Post by: Alan on August 23, 2016, 07:52:02 PM
Anytime multiple switch mode power supplies are used in a parallel configuration (which yours will be when a wheel bridges the rail gap) you should put a high current schottky diode in the positive supply lead to isolate the voltage regulation sections of the power supplies from each other else strange things can happen.
http://www.mouser.com/ProductDetail/Fairchild-Semiconductor/SB1245/?qs=sGAEpiMZZMtQ8nqTKtFS%2fDJWInRO8leYd%2f7HCUlqa%252bw%3d (http://www.mouser.com/ProductDetail/Fairchild-Semiconductor/SB1245/?qs=sGAEpiMZZMtQ8nqTKtFS%2fDJWInRO8leYd%2f7HCUlqa%252bw%3d)
Post by: SD90 on August 23, 2016, 08:22:10 PM
Yes, just the red wires must be insulated from each other. Can you place the power supply in the corner?
Yes, the power supply could be placed in the corner, any of them.
Imagine the basement is a square, with the 7x8 bump out at the top, I thought of putting the power supply at the top, so I could power the helix and have 3 bus lines (1 for each level) going in each direction from there.
I appreciate the replies!
Thank you!
Post by: SD90 on September 01, 2016, 05:50:19 PM
Post by: Alan on September 01, 2016, 07:23:56 PM
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If I use more than 1 power supply, can I just insulate both rails?
No, unless the PS manufacturer specifically states the units can be paralleled. Typically, you won't find that in low cost consumer products. It all depends on what circuitry the manufacturer uses for voltage regulation. We have no way of knowing this.
As a loco crosses the gap both power supplies are connected via the front wheels and back wheels. The momentary condition may or may not be a problem. But what if the loco sits parked straddling the gap? The regulators may become unstable creating a runaway voltage effect. Poof goes your modules.
Another consideration is short circuits. If a derailment caused short occurs while the gaps are bridged then the full current from both PSs will flow through the short. A pair of 5A PSs = 10A which melts trains.
Here is a two page document explaining how to parallel connect PS. Can you do everything on page 1? If not then see page 2.
http://www.frei.de/assets/templates/frei/Dateien/Dateien/PDF/Stromversorgungen/en/Technische_Beschreibung_Parallelschaltung_ENGL.pdf (http://www.frei.de/assets/templates/frei/Dateien/Dateien/PDF/Stromversorgungen/en/Technische_Beschreibung_Parallelschaltung_ENGL.pdf)
The diode solution is easy enough and costs less than $5. Then you don't ever have to worry.
Post by: yvesmary on September 01, 2016, 08:15:17 PM
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As a loco crosses the gap both power supplies are connected via the front wheels and back wheels. The momentary condition may or may not be a problem. But what if the loco sits parked straddling the gap? The regulators may become unstable creating a runaway voltage effect. Poof goes your modules.
Does this apply to my setup? I have a PWR-56 powering the lower level which goes up a helix and at the top the rails are gapped (insulated joiners) and the upper level is powered by another PWR-56.
Thank you,
Yves in Alberta
Post by: William Brillinger on September 01, 2016, 08:52:49 PM
www.ringengineering.com/RailPro/Documents/PWR-56UsersManual.pdf
Post by: G8B4Life on September 01, 2016, 09:12:43 PM
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Does this apply to my setup? I have a PWR-56 powering the lower level which goes up a helix and at the top the rails are gapped (insulated joiners) and the upper level is powered by another PWR-56.
No. As Bill posted, the PWR-56 manual provides all the info needed for using multiple PWR-56's together. You just have to gap the positive rails and install at the appropriate place. Unless I'm grossly mistaken Ring would have built in all the required circuitry to handle race conditions, overload from shorts at power boundaries etc. I've never opened a PWR-56 up to see what's in there but I highly doubt it'd just be a radio controlled on/off switch.
All the info from Alan (which is great info, thanks Alan) would apply if you were using other power supplies, like the one's that Alan uses and I have that may or may not be specifically made to work together.
- Tim
Post by: Dean on September 01, 2016, 10:52:35 PM
DCC has a whole different set of rules.
Post by: G8B4Life on September 01, 2016, 11:16:36 PM
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May I presume that all this great information is for layouts that are RailPro only.
Correct. I think we could go further and say it is for layouts that are DC based but I don't know of any analogue/conventional control DC layouts that use 2 or more parallel power supplies.
DCC boosters, as with the PWR-56 are made to be worked together (power districts) and one would presume that all the required wizardry to prevent the conditions Alan describes are present in the DCC booster. It's probably different for DCC being square wave AC (Alan will most likely know) but I'm sure the principals are the same and that the relevant precautions would have been taken in the design of the boosters.
- Tim
Post by: Alan on September 02, 2016, 08:15:06 PM
Tim is correct about my recommendation applying to non-Ring power supplies. Sorry Bill, but I can't understand why someone would buy a $120 PWR56 when a $19 power supply will run trains just fine. And the bit about a PWR56 regulating the voltage to +-3% is a feature with no benefit. On a layout of any decent size the resistance in the track and bus wiring will cause more voltage deviation than the power supply regulation spec. Besides, 3% is not uncommon. My eBay power supplies regulate that well too not that it matters. How do I know?
Post by: William Brillinger on September 02, 2016, 08:38:34 PM
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Sorry Bill, but I can't understand why someone would buy a $120 PWR56 when a $19 power supply will run trains just fine.
I don't know why anyone would pay $120 either. It's only $91.96 with shipping on PDC.CA ;)
However I can think of a few reasons to choose the PWR56:
- fault reporting and control integration of the PWR56 with the HC
- repeater function (handy on larger layouts)
- simplicity of wiring (no extra monitors needed)
...and when purchased with an HC the pricing is not bad; it comes with an HC for only $69 in the RPK1 set.
Odds are if your layout is big enough to need to PWR56's then you'll want at least 2 HC's anyway.
Post by: Alan on September 02, 2016, 10:39:54 PM
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However I can think of a few reasons to choose the PWR56:
- fault reporting and control integration of the PWR56 with the HC
- repeater function (handy on larger layouts)
- simplicity of wiring (no extra monitors needed)
If I'm not mistaken the PWR56 integration (ability to the power on/off) is for the gizmo, not the actual power supply brick. Even though there is no power going to the track when the PWR56 is turned off, the brick is still running. One has to ask why a remote control on/off button if it doesn't really turn the power supply on/off? And do I really need to know the temperature? All power supplies have integrated over-temp shutdown. The lawyers see to that. A device that catches fire is bad for business. Just ask Samsung right now about their Note 7 recall. For fault reporting a simple LED across the bus does the job just fine. One can put a lot of LEDs on the fascia panel for $100.00. ;)
Repeater - yeah I understand that. Range has not been an issue fro me. My HC works from the other side of the basement 70' from the train room. But I imagine it is a different story in a busy radio environment like a show or apartment complex. I'll give you that one.
Voltage monitoring on a RailPro layout is absurdly easy. A $2.00 panel voltmeter does the job. It is a tie score on simplicity - Ring 2, Generic 2. PWR56 & brick compared to eBay PS and voltmeter. If you count actual number of wire connections needed then generic wins - Ring 7, Generic 6.
Ring had to offer a power supply to make his product a complete system. I get that. The off-the-shelf generic laptop brick he uses probably is sloppy on the voltage regulation as most bricks are. Bricks also are not suitable for a multiple power supply setup and Tim had to expect modelers to ask for such. So it makes sense he also supplies his gizmo interface which is no doubt a precision voltage regulator. That's why it gets hot and he is concerned about the mounting position. The radio communication is his trademark market differentiation so it too makes sense he includes it.
I am not saying anything bad about the PWR56. I am a delighted RailPro customer. Just making the point that for frugal folk such as myself there is a lot of money to be saved when it comes to power supplies. Money I can spend elsewhere on the layout.
Post by: William Brillinger on September 02, 2016, 10:50:21 PM
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Just making the point that for frugal folk such as myself there is a lot of money to be saved when it comes to power supplies. Money I can spend elsewhere on the layout.
Absolutely True.
Post by: G8B4Life on September 03, 2016, 11:29:26 AM
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Just making the point that for frugal folk such as myself there is a lot of money to be saved when it comes to power supplies. Money I can spend elsewhere on the layout.
You don't have to be frugal, just informed. Ring doesn't exactly go around stating that you can use any power supply that outputs ~14volts but quite purposefully goes about promoting their power supply as the only suitable and RE endorsed supply for their system. Nothing wrong with that, that's good business sense to promote your own stuff but it probably does leave most just going with the RE supply than investigating other options. Even I was not 100% sure until I had the thing in my hands.
I also would imagine the number of PWR-56's sold in the starter kits would far outnumber the number of PWR-56's sold separately. This brings us back to the point you made about a complete system, I don't think many, if any modellers would normally have a suitable power supply just laying around so the inclusion of one in a starter kit is a great way of getting going. That's how I did it. Now I have a large 15v 20 something amp SMPS (price was good) which I can break down into separate districts easily enough if needed and the PWR-56 can be used on a test bench.
Another way to look at it (I don't know if RE does or does not look at it this way) is if your trying to lure folk over from DCC you might try to capitalise on the mindset they might have, that being they need an expensive booster for every power district in DCC so if the mindset has set in and they don't think too hard they might just think they need an expensive PWR-56 for each district too.
I think if people needed the repeater functionality but wanted to use their own power supply it would be great if Ring sold the PWR-56 part (the brick is PA-2) separately but I don't see that happening, limitation of liability etc.
- Tim
Post by: Alan on September 03, 2016, 11:58:25 AM
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need an expensive booster for every power district in DCC
Is that really true? I thought you only had to add DCC circuit breaker units for each power district.
Post by: Dean on September 03, 2016, 01:18:30 PM
Quoteneed an expensive booster for every power district in DCC
Is that really true? I thought you only had to add DCC circuit breaker units for each power district.
Yes that's true. If wanted to split my layout into two sections, I would have buy another booster and power supply and run communication cabling back to the main booster. Throw in some circuit breakers and it starts to get expensive.
What I like about the PWR-56 is the fact that you can kill all the power to the track from any place around the layout. I could have used that feature on a couple of occasions. :-[
Post by: Alan on September 03, 2016, 04:36:11 PM
Post by: G8B4Life on September 04, 2016, 03:00:23 AM
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Is that really true? I thought you only had to add DCC circuit breaker units for each power district.
Yes and no. Circuit breakers can be used to make power districts, but the typical electronic DCC circuit breakers that are most useful for that purpose I believe are a relatively modern (in the age of DCC itself) development. Before that you used light bulbs (ugh!) or another booster.
The diagram in this article (tonystrains.com/download/MRR-PowerDist.pdf (http://tonystrains.com/download/MRR-PowerDist.pdf)) shows a most likely setup for an informed DCC user today. A user from 10 years ago or an uninformed user of today might have each one of those breakers saying Booster instead. There is a lot of literature around that teaches "except for all but the smallest layouts if you want to run a lot of trains at once, or a number of sound ones break up your layout into districts with smaller capacity boosters rather than using 1 big booster for the whole layout". This is the mindset I talked about.
Going back to the article, our advantage is we can buy a single supply relatively cheap that totals all those boosters and split off from that using breakers (also cheap thanks to it being DC) for our districts. If we need another supply, well that's cheap too. With DCC most small scale boosters are 3 or 5 amp so once your approaching the limit of a single booster (as a heavy yard or engine terminal theoretically could) you need another expensive booster (or more) for other parts of the railroad, or replace with a large really expensive booster - if it's suitable for small scale decoders that is.
- Tim
Post by: SD90 on September 05, 2016, 02:10:03 PM
...and when purchased with an HC the pricing is not bad; it comes with an HC for only $69 in the RPK1 set.
Odds are if your layout is big enough to need to PWR56's then you'll want at least 2 HC's anyway.
That's a very good way to get another power supply, I never thought of just getting 2 starter kits, I planned on getting 2 throttles anyway!