Power Districts

[gavino200]

I'm thinking about how I can divide my layout into districts. I'm talking about separating different parts of a layout electrically, so that when one part shorts, the rest stay running. It's very common in the US to do this. It's not absolutely necessary for me, as my Digikeijs controller has an electronic circuit breaker in it. But if I can do it easily, I'd like to do it.

 

There are a few US products that allow you to split a power district into smaller districts. One of them, I know is compatible with RailCom. But I've heard that others are not.

 

I don't see any European products out there for doing this. Is this just not a consideration among European modellers? Do people just rely on boosters to create districts. This seems like it would work fine, though you either have few districts of you use boosters redundantly, which is fine but probably wasteful.

 

Any thoughts? @Martijn Meerts?, @Dani?

 

The common US products I know of are as follows.

Digitrax PM42 (with breakout board). I've used this before. Personally I dislike Digitrax and I'm not interested in using this. But I've read that it's troublesome with RailCom, and that it is too slow to work well with the electronic circuit breaker in the Digikeijs system (even though the speed can be programmed).

 

DCC Specialties PSX range, are widely praised. I found this guy on YouTube who had problems with them and had to go back to using a PM42.

 

Tam Valley Depot seems to have made a circuit breaker in the past, but it doesn't look like they're still producing it.

 

NCE EB1 make a circuit breaker that I've been told works with RailCom, but I'm not sure if it can be daisy-chained like the PSX to split a Booster district into different power districts. It seems designed to just protect a booster. I wouldn't need that as Digikeijs boosters have a built in electronic circuit breaker.

 

I don't see any European products. Is this just a US thing?

Edited April 6, 2022 by gavino200

[gavino200]

So, making a little progress on this.

 

If I use circuit breakers to divide the layout into regional buses, I'll be using the NCE EB1. I have a first hand account of it functioning well with both RailCom and with Digikeijs boosters. The DCC Specialties PSX series are also supposed to be compatible with RailCom, however I know one person who couldn't get it to function with RailCom even with direct correspondence and input from the designer. There are multiple accounts of the PM42 having trouble with both RailCom and the Digitrax boosters so that's out.

 

However.....considering my layout, this approach may not be the best for me. Bear in mind, I don't actually need extra circuit breakers for safety reasons. The electronic cirucuit breakers in the Digikeijs boosters are reliable. My main reason is so that a derailment doesn't take down the entire layout. But I guess that wouldn't be the biggest disaster.

 

The problem with a standard bus setup comes up when factoring in the block detection units. I'm using DR5088RCs. Each supplies 16 blocks and some non feedback track. It makes sense to have the wires coming from this unit to the track be as short as possible. These will be my feeders. In order to do this it makes sense to place these units at intervals, and to have feeders from the DR5088RC to whatever blocks are nearest regardless of what layout loop/yard/etc they belong to. My "bus"would be the wires coming from the DR5000 or the booster to the DR5088RCs. Unfortunately that would make it difficult to break the layout into power districts, each with independent circuit breakers based on layout topography. I think this is a reasonable tradeoff.

 

\

 

This picture from my DR5088RC manual

 

 

However, it leaves me with a second problem - how many DR5088RCs can I connect to one booster. I was hoping to rely on the rule of thumb that one 3 Amp booster can run 10 trains. But I see I'll have to be a little more sophisticated. Perhaps there's a way to read the current output of a booster directly.

 

 

 

[gavino200]

Looking at the diagram, I see that I should be able to incorporate the breakers if I want. I'd simply split the wires between the DR5000 and the DR5088 daisy-chain and place an NCE EB1 between the 5000 and the 5088.

 

So, with consideration to my layout below I think I'll divide it into three districts, blue, red, and purple. The blue will on one bus supplied by the DR5000. I'll use a booster for the Red and purple sections, separated into two districts using an NCE EB1.

 

If running the whole blue section with the DR5000 turns out to be underpowered, I'll add a booster and divide it into two booster districts.

 

I'd like to find a better way to calculate load on a booster than, how many trains is it running. I'll see if it's possible to read current usage directly from the booster using the interface.

 

 

[gavino200]

So, after research, reading, shopping, threads on multiple fora, and much cogitation I have a system plan for my new layout.

 

I'll use my Digikeijs DR5000 Command Station to power an accessory bus. 

The accessory bus will power DR4018 units for signals and DR4024 units for turnout servos as well as DR4102 frog polarity inverters.

 

I'll use a Digikeijs DR5033 Booster to power the blue track area on it's own bus. This bus will supply DR5088RC feedback monitor units.

 

A second Digikeijs DR5033 Booster will power the red and purple track areas. I'll separate this booster district into two power districts using two NCE EB1 Circuit breakers. Each power district will have it's own bus. The two buses will supply DR5088RC feedback monitor units.

 

There'll be a LocoNet bus along the length of the layout, using DR5099 LocoNet hubs. This will connect the DR5088RC units.

 

I'm going to place relays on the lines feeding each of the main three districts. These will be controlled by a DR4018 on the accessory bus. Then I'll be able to switch off individual districts from iTrain. I may extend this to include the yards separately also, depending on the number of junctions.

 

That's it. The advantage of using an accessary bus instead of the @chadbagLoconet trick to power the switch and signal units is that it will eliminate dozens of 12V "wall-wort" power supplies. Anyone see any problems with this setup? @chadbag?, @Martijn Meerts?, @Madsing, @Kiha66?, @Dani?

 

At al later stage I'm going to have to think about an LED controller for the general layout LEDs. I think an Arduino/RasPi solution would probably be best for this. It likely wouldn't talk with iTrain, but really I don't think it has to. It could probably be linked somehow using relays if necessary.

 

 

 

 

Edited April 8, 2022 by gavino200

[Martijn Meerts]

That would certainly work, although all data will still go through the command station, so depending on how many trains are running / how many turnouts you have / how many feedback modules you have, and how many of all those are running / triggered at the same time, your command station might be a bottle neck. I don't really think it should be an issue, the layout is relatively not big compared to what a command station should be able to handle. Also, I'm not very familiar with the Digikeijs system, so not really sure what the limitations are.

 

[Madsing]

Ok. No real objection.

Intuitively, I have tried to load my DCC bus as little as possible and keep its current/power for trains. I am using Tomix switches and they require an awful lot of current when switching, I didn't want that surge to affect communication to the trains in any way. However, I understand that you will have a separate accessory DCC bus with its own booster, so my remark does not apply. Also, I have read that Kato switches require less current than Tomix switches. In case you change your mind, don't ever think about using "dozens" of wall wart power supplies, replace all of them by a stable, protected power supply such as this one: https://www.aliexpress.com/item/1005003750997278.html. Plenty of current for a few dollars.

 

Regarding the LED controller, you can consider using the same as mine. I have recently added more details about it to my blog: https://shin-yukari.weebly.com/led-controller.html. I am more than willing to help should you want to experiment with that.

 

Marc

[gavino200]

3 hours ago, Martijn Meerts said:

That would certainly work, although all data will still go through the command station, so depending on how many trains are running / how many turnouts you have / how many feedback modules you have, and how many of all those are running / triggered at the same time, your command station might be a bottle neck. I don't really think it should be an issue, the layout is relatively not big compared to what a command station should be able to handle. Also, I'm not very familiar with the Digikeijs system, so not really sure what the limitations are.

 

 

Yes, that could be a problem. The Digikeijs guys don't seem to be too concerned about it. If it turns out to be overloaded it won't be difficult to add a second command station. An advantage of the Digkeijs command center is that it's actually relatively inexpensive. I'm curious to see if it can handle the load, and also what it will look like if it can't.

[gavino200]

1 hour ago, Madsing said:

Intuitively, I have tried to load my DCC bus as little as possible and keep its current/power for trains. I am using Tomix switches and they require an awful lot of current when switching, I didn't want that surge to affect communication to the trains in any way. However, I understand that you will have a separate accessory DCC bus with its own booster, so my remark does not apply. Also, I have read that Kato switches require less current than Tomix switches.

 

Yes, the switches will have their own power. I'm going to be using Peco turnouts with small servo motors. I don't really know what the power needs will be. The inbuilt booster in command center should be able to handle it, but I can add a booster if I ever exceed it's output. Maybe a bigger question, as Martijn mentioned is whether the command center will be overloaded. I'm guessing it should be fine, but I can add a second if it does.

 

1 hour ago, Madsing said:

 

In case you change your mind, don't ever think about using "dozens" of wall wart power supplies, replace all of them by a stable, protected power supply such as this one: https://www.aliexpress.com/item/1005003750997278.html. Plenty of current for a few dollars.

 

Yess! A single designated 12V DC power bus would be a great idea! Those are really cheap. The different terminals are for different possible values? You just hook the bus up tho the terminal corresponding to the Amperage that you want?

 

 

1 hour ago, Madsing said:

 

Regarding the LED controller, you can consider using the same as mine. I have recently added more details about it to my blog: https://shin-yukari.weebly.com/led-controller.html. I am more than willing to help should you want to experiment with that.

 

 

Yes!! Definitely. Nice system, and also nice blog entry! It's going to be a while before I get around to that, though. 🤣

[gavino200]

I found a nice little video on making a DC power bus. It talks about using something called a "buck board" which is a small cheap step-down transformer to run arduinos or other elements that run on a lower voltage. 

 

The video also reminded me that I have a ton of old audio cable that I'll be able to re-use.

 

 

[Martijn Meerts]

2 hours ago, gavino200 said:

 

Yes, that could be a problem. The Digikeijs guys don't seem to be too concerned about it. If it turns out to be overloaded it won't be difficult to add a second command station. An advantage of the Digkeijs command center is that it's actually relatively inexpensive. I'm curious to see if it can handle the load, and also what it will look like if it can't.

 

I'm quite curious as well, I'm thinking about which DCC system to use for the T-Trak modules. I could just use the ECoS, but I'd rather keep that in place on the big N-scale layout. Also, the ECoS uses S88 for occupancy detection, which can be annoying with modules, since you can't set addresses on S88 detectors. The Digikeijs system could be a good option.

 

[cteno4]

4 hours ago, Madsing said:

Regarding the LED controller, you can consider using the same as mine. I have recently added more details about it to my blog: https://shin-yukari.weebly.com/led-controller.html. I am more than willing to help should you want to experiment with that.

 

Nice article marc! I’ve been looking at the ATtinys for like 2-6 channel control for exactly this of setting led levels and doing some random on and off of lights in buildings. But I’ve just not had the time and opportunity to sit down and get into arduino programming, especially the serial addressing of a bunch of chips on a bus. My though was a chip per building as they are down to a dollar now.

 

jeff

[Madsing]

20 hours ago, gavino200 said:

Yess! A single designated 12V DC power bus would be a great idea! Those are really cheap. The different terminals are for different possible values? You just hook the bus up tho the terminal corresponding to the Amperage that you want?

No. You have to choose the power/amperage when you purchase the power supply. The 1.25A unit is very compact, the 30A one is much bigger as all components inside are dimensioned according to the maximum current. Remember that, for a power supply, the current (unit: A = Ampere) is the maximum current that the unit can supply. The actual current will always be determined by the devices connected, and their power consumption. So there is no harm purchasing a power supply that is capable of delivering more current than required. In fact, it's even good practice, to be safe, and to let the power supply work below its maximum limit.

Maximum Power = Voltage x Maximum Current. The unit is W for Watt. So, the power of a 12V power supply capable of delivering maximum 3A is 12 x 3 = 36W.

(Sorry, maybe you know all this already, I have no idea... 😀)

 

The power supplies in the link (https://www.aliexpress.com/item/1005003750997278.html) have multiple terminals, but it's only for redundancy. The terminals are

- Live, Neutral and Ground (Earth): Power input, AC 100V-265V

- V+ and V-: the DC 12V power output. These can be duplicated two or three times for convenience.

 

If you are not comfortable with these, there are also fully enclosed power supplies like these https://www.aliexpress.com/item/1005003470250892.html. Their characteristics are similar, but they are safer (especially if you have kids at home) as they cannot be opened. That's the kind I mostly use.

 

Marc

[gavino200]

11 hours ago, Madsing said:

No. You have to choose the power/amperage when you purchase the power supply. The 1.25A unit is very compact, the 30A one is much bigger as all components inside are dimensioned according to the maximum current. Remember that, for a power supply, the current (unit: A = Ampere) is the maximum current that the unit can supply. The actual current will always be determined by the devices connected, and their power consumption. So there is no harm purchasing a power supply that is capable of delivering more current than required. In fact, it's even good practice, to be safe, and to let the power supply work below its maximum limit.

Maximum Power = Voltage x Maximum Current. The unit is W for Watt. So, the power of a 12V power supply capable of delivering maximum 3A is 12 x 3 = 36W.

(Sorry, maybe you know all this already, I have no idea... 😀)

 

Thanks! That's really helpful. I know I knew this at one stage. But physics was a long time ago. I had forgotten this for sure and didn't know what to make of the Wattage number. Now it's crystal clear.

 

11 hours ago, Madsing said:

 

The power supplies in the link (https://www.aliexpress.com/item/1005003750997278.html) have multiple terminals, but it's only for redundancy. The terminals are

- Live, Neutral and Ground (Earth): Power input, AC 100V-265V

- V+ and V-: the DC 12V power output. These can be duplicated two or three times for convenience.

 

Gotcha. So for input I'd just take the same plug cable as for a computer or a closed power supply, identify the wires correctly, and connect them to the live, neutral and ground.

 

11 hours ago, Madsing said:

 

If you are not comfortable with these, there are also fully enclosed power supplies like these https://www.aliexpress.com/item/1005003470250892.html. Their characteristics are similar, but they are safer (especially if you have kids at home) as they cannot be opened. That's the kind I mostly use.

 

 

Well, yeah. Those are in my comfort zone. But I've been curious about the open units for a while. And I do like to extend my comfort zone. 😂 My son is 14 and knows not to mess with these things. It's always nice to have more options.

 

Thanks again, Marc, for explaining!!

Edited April 10, 2022 by gavino200

[gavino200]

An interesting video I found about fixing aluminum case power supplies. It also shows how to hook them up. This one is specifically about hooking them up.

 

 

Edited April 10, 2022 by gavino200

[Dani]

On 4/9/2022 at 12:04 AM, gavino200 said:

I'm going to place relays on the lines feeding each of the main three districts. These will be controlled by a DR4018 on the accessory bus. Then I'll be able to switch off individual districts from iTrain. I may extend this to include the yards separately also, depending on the number of junctions.

 

Hi Gavino,

 

I'm just wandering if installing relays to switch off districts can cause you any trouble. I'm using Rocrail and I have no experience in iTrain. But you switch off a track section that has current sensors, the current sensor will probably send a signal to the software to indicate there is no train (there is no consumption, so there is no train). And the opposite when you turn it on. This can drive the software crazy so in automatic mode it can block your entire layout with an emergency brake. It's just theory.

 

I wouldn't spend money in circuit breakers nor boosters until you make sure you need them. I'm also using a DR5000, and until the modular layout of the club was over 50 meters long, we didn't need any booster. And we needed it not because of the length, but because of the number of trains on the layout. I think we had like 12-15 full trains all illuminated and with sound, and the command station was not delivering enough power so some trains were not playing sounds.

 

Then you only need to isolate both rails at some point to create the districts, and feed this part with an independent booster. So I suggest you to divide you layout in isolated zones, but connect all them to the DR5000. You will see if you need a booster, and installation is really easy, just disconnect one of the isolated districts from the DR5000 and connect it to the booster. Prepare the layout, but don't buy boosters in advance because probably you won't need them. This is just a humble suggestion.

 

I'll share which is my strategy for power feeding, I'm not experienced in other systems, but this one I can say it works for really big modular layouts with many trains running at the same time:

 

• Rail current (DCC) is only used to feed trains. No modules connected, no servos, no light, no decoders to switch lights, ... no nothing. Just trains.
• I have two power lines:
  • 5V power line is exclusively to feed servo motors (they are really sensitive to current fluctuation)
  • 12V power line to feed illumination or any other device
• In my opinion your DR5000 Loconet bus has enough power to feed all your Loconet modules, in case it doesn't you can use a Loconet booster. I'm using a GCA101 board which delivers 3Amp to the Loconet bus, we need it because when we join all modules we have more than 50 loconet modules (for servos, illumination, current sensors, sound....). But again, wait until you find you need it.

By the way, for the 5V and 12V power lines I'm using a common ATX power source like those used computers. You have plenty of power for each of the lines.

 

I hope this can help you!!!

 

 

 

 

 

[gavino200]

2 hours ago, Dani said:

 

Hi Gavino,

 

I'm just wandering if installing relays to switch off districts can cause you any trouble. I'm using Rocrail and I have no experience in iTrain. But you switch off a track section that has current sensors, the current sensor will probably send a signal to the software to indicate there is no train (there is no consumption, so there is no train). And the opposite when you turn it on. This can drive the software crazy so in automatic mode it can block your entire layout with an emergency brake. It's just theory.

 

I heard about the stategy from a mod on the iTrain forum. I bet it works, but it may be more trouble for me than it's really  worth.

 

2 hours ago, Dani said:

I wouldn't spend money in circuit breakers nor boosters until you make sure you need them. I'm also using a DR5000, and until the modular layout of the club was over 50 meters long, we didn't need any booster. And we needed it not because of the length, but because of the number of trains on the layout. I think we had like 12-15 full trains all illuminated and with sound, and the command station was not delivering enough power so some trains were not playing sounds.

 

Then you only need to isolate both rails at some point to create the districts, and feed this part with an independent booster. So I suggest you to divide you layout in isolated zones, but connect all them to the DR5000. You will see if you need a booster, and installation is really easy, just disconnect one of the isolated districts from the DR5000 and connect it to the booster. Prepare the layout, but don't buy boosters in advance because probably you won't need them. This is just a humble suggestion.

 

Well, I'm hoping to get a bunch of trains running, but you're right, I may not need a separate booster for the second and third track areas. The advantage of separating them is that parts of the layout keep running if there's a short on one part.

 

There's a second more important reason to make a designated accessory bus that isn't related to power or DCC bandwidth. Most shorts are caused by trains going through a junction the wrong way. If the junctions are powered and controlled separately to the track, then you can still control the junction even though there's a train stuck on it. You can simply switch the junction and the trains start running again WITHOUT physically going over there to move the trains. This can be done either by using separate circuit breakers or by using a booster. There isn't a huge difference in cost.

 

 

2 hours ago, Dani said:

 

I'll share which is my strategy for power feeding, I'm not experienced in other systems, but this one I can say it works for really big modular layouts with many trains running at the same time:

 

• Rail current (DCC) is only used to feed trains. No modules connected, no servos, no light, no decoders to switch lights, ... no nothing. Just trains.
• I have two power lines:
  • 5V power line is exclusively to feed servo motors (they are really sensitive to current fluctuation)
  • 12V power line to feed illumination or any other device
• In my opinion your DR5000 Loconet bus has enough power to feed all your Loconet modules, in case it doesn't you can use a Loconet booster. I'm using a GCA101 board which delivers 3Amp to the Loconet bus, we need it because when we join all modules we have more than 50 loconet modules (for servos, illumination, current sensors, sound....). But again, wait until you find you need it.

By the way, for the 5V and 12V power lines I'm using a common ATX power source like those used computers. You have plenty of power for each of the lines.

 

I hope this can help you!!!

 

 

Thanks Dani, that's very helpful.