What do people use as a secondary power supply?

[Sir TophamHatt]

A read a lot of people have a secondary 16v power supply for things like points and lights.

 

Can someone show me an example of this and how they set it up?

[letterspider]

This is the set up I am working on - excuse the poor drawing

 

]

 

Using the eLink for digital control of track and accessories. 

ESU switchpilots to control points and signals

Peco point motors

 

This is a simplified set up because I am using the track to carry all digital command signals and power to the locos and to the accessory decoders. Experienced modellers would also have a parallel supply of running wires under the baseboard supplying the track and accessory decoders with regular feed of power and digital signals . However as I have triple and quadruple track in several sections -  for simplification I use those other tracks as feeders (they are after all pretty thick metal conductors!)

 

The PECO point motors draw a lot of power, the ESU Switchpilot cannot divert high currents from the track, through its circuitry and to the point motors. So in order to stick with my PECO point motors I will have to supply them with an independent 16V power supply. The ESU Switchpilot then has the job only of switching that power on and off to the points which I command

 

You can download the comprehensive manual on how to do this from here:

 

http://www.esu.eu/en/downloads/instruction-manuals/digital-decoders/

 

I am also using this 16V to supply lighting to scenery and this can also be controlled by the Switchpilot

 

The 16V DC supply is recycled from an old Scalextrix set

Edited July 10, 2020 by letterspider

[Oldddudders]

1 hour ago, Sir TophamHatt said:

A read a lot of people have a secondary 16v power supply for things like points and lights.

 

Can someone show me an example of this and how they set it up?

I'm not sure what you are looking to clarify. If I need a secondary supply, I buy an appropriate PSU, possibly a laptop PSU, plug it in and attach the accessories to the output. What is difficult?

[Sir TophamHatt]

23 minutes ago, Oldddudders said:

I'm not sure what you are looking to clarify.

 

A question of whether you can power platform lighting, signal lighting and points all from the same secondary power source?

 

Seep point motors need a CDU. Mine is in place between the controller and the accessory bus wires.

 

Signals seem not to want to work when connected to the accessory bus wire.

 

So it's a question of whether I need a 3rd power supply or can I split the 2nd power supply into two, have one for lights and the other (via a CDU) for point motors.

 

Many power supplies come at 19v but what I'm using now is 16v. In order to split a new psu, I guess 16v terminal blocks are out of the question? 

Edited July 10, 2020 by Sir TophamHatt

[MartynJPearson]

You can power everything from one supply, as long as you are mindful of the current that you are drawing. If your lighting and signalling is a few LEDs then all well and good, but things do start to add up so check the rating of your power supply.

 

One other caution is that devices that draw high current - like solenoids, point motors etc, can cause a flicker - but a CDU as already suggested will help reduce or remove that.

 

As for what to use - I use an old Gaugemaster controller which has a 16v output - a lot of DC controllers beyond the train set basic variety from way back when have 16 volt outputs.

[Oldddudders]

The CDU should only feed the point motors. It is not wise to send a big spike to anything else, so place it directly before the points. 

[Alister_G]

I use a Gaugemaster GM-GMC-M1 16 V AC Cased Transformer, which has 2 separate 16V AC outlets. They are expensive, but they're bloody bombproof.

 

Al.

[Mick Bonwick]

4 hours ago, Sir TophamHatt said:

A read a lot of people have a secondary 16v power supply for things like points and lights.

 

Can someone show me an example of this and how they set it up?

 

Are you using your DCC system to change points? What sort of lights are you using or planning to use? Are you using your DCC system to change signals, and are these semaphore or colour light? You will need to be more specific about your requirements if you hope to get a full answer. You haven't supplied very much information that will help respondents.

[corax67]

I’m with Alister_G - Gaugemaster for me too on our church exhibition layout and my own layouts too.

 

 

Karl

[Dagworth]

3 hours ago, letterspider said:

This is a simplified set up because I am using the track to carry all digital command signals and power to the locos and to the accessory decoders. Experienced modellers would also have a parallel supply of running wires under the baseboard supplying the track and accessory decoders with regular feed of power and digital signals . However as I have triple and quadruple track in several sections -  for simplification I use those other tracks as feeders (they are after all pretty thick metal conductors!)

The reason for having a seperate DCC data send to the point decoders is so that when you inevitably run a loco into a wrongly set point and short out the DCC system you can switch off the track feed, re-establish the DCC power, change the points and then switch the track feed back on without having to manually drag the offending loco backwards off the point in order to get the DCC power active again. Nothing to do with the current of the DCC signal to the point decoders, what they draw on the data line is so small it can be ignored.

 

Andi

[DCB]

6 hours ago, Oldddudders said:

I'm not sure what you are looking to clarify. If I need a secondary supply, I buy an appropriate PSU, possibly a laptop PSU, plug it in and attach the accessories to the output. What is difficult?

Laptop PSUs aren't designed to be shorted out on a regular basis in the way model Railway transformers etc are.    If you use PSUs not designed for model railways its best to provide overload protection, maybe just a polyswitch (effectively an auto re setting thermal cut out) or maybe a fuse.  I have seen transformers which have actually been on fire. Having said that I have had several laptop PSUs where the wires in the connector at the laptop end has failed and made an otherwise excellent PSU unusable on a laptop.  

[Il Grifone]

IMHO it's best to use a separate transformer for each function - point/signal solenoids (whether using a CDU or not), track circuits, lighting etc. This avoids interaction and other problems.

 

A power unit with an independent 'tertiary' winding is probably OK, but it would depend on the magnetic circuit (quantity of iron).

 

A car stop/tail bulb (Incandescent not LED) can be used as a short-circuit protection. Wire the stop filament (the thicker one) in series with the supply.

[Ravenser]

As a practical issue , you can only power things running off the same voltage off the same transformer - unless you take an extra step.

 

So assuming your auxilary supply is 16V AC, then you can run solenoids off that, and anything else that takes a 16V AC supply . But you can't run LEDs (I'm a bit sensitive to the repeated mention of lights in this thread...)

 

To take a practical example , my layout, Blacklade has effectively 3 circuits : Blacklade wiring

 

- The traction bus : DCC supply to track off NCE PowerCab. (This also supplies the data signal to the accessory decoders, and used to supply NCE Switch-Its before I replaced them, as that's te only way to power them)

 

- The 16V AC auxiliary bus. Fed by a surplus Lenz 45VA transformer at 16V AC. Originally fed a MERG decoder directly (they use 16V AC power feed) but this has been replaced by a second Digitrax DS64 . Those don't like 16V AC - I've read it destroys them in short order, despite claims in the instructions) So in practice this now feeds two  stabilised power supply units from Express Models and someone else . These step 16V AC down to 12V DC stabilised, and power the LEDs in the signals and the two Digitrax DS64s . Power for a Conrad point motor is tapped directly off the 16V bus and switched through the spare contacts on a Tortoise - these two points form a crossover.

 

- 15V DC Uncoupler bus - Fed by a Maplins switchable voltage regulated transformer set to deliver 15V DC / 4.0A to power the Kadee electromagnetic uncouplers. Circuit confined to one board

 

The traction bus is black and red solid cable from mains cables

The 16V AC auxiliary bus is blue and yellow "5A" rated wire

The 15V DC uncouplers are on brown "5A" wire

 

Hope that helps as a practical example

[Sir TophamHatt]

16 hours ago, Mick Bonwick said:

 

Are you using your DCC system to change points? What sort of lights are you using or planning to use? Are you using your DCC system to change signals, and are these semaphore or colour light? You will need to be more specific about your requirements if you hope to get a full answer. You haven't supplied very much information that will help respondents.

 

No, using DC system for points with toggle switches. I didn't think about the CDU until now so just wired it up after the controller and then run bus wires for the points.

 

Lights are Eckon LEDs with special control boards for automatic operation. I'm now guessing I'll need to use a separate power supply for these.

 

The post was just asking what people use to power other things apart from the tracks and how they use it (bus wires? terminal blocks? more than one output?).

[Sir TophamHatt]

5 hours ago, Il Grifone said:

IMHO it's best to use a separate transformer for each function - point/signal solenoids (whether using a CDU or not), track circuits, lighting etc. This avoids interaction and other problems.

 

This is where it gets more interesting as I watched a video on YouTube with a guy who used a PC power unit. These have lots of 12v outputs. Although the person in the video soldered them all together, I wonder whether each one could be used to power something different but then only the one "other" power supply is needed.

 

Here's the video:

 

 

[Il Grifone]

I can't help with the internals on a PC power unit I'm afraid. I would expect they are all different anyway and I suspect each output at the same voltage are common. (Don't quote me on that!)

I have repaired them back in the day, but really they were so cheap as not to be worth the trouble.

 

My usual way of wiring everything up is to use a common return bus (2.5mm² at least depending on the size of the layout and the quantity of accessories), connected to earth for electrical safety and to reduce interference. Each category of load then has its own supply. Everything but the smallest layout requires at least two controllers - to run two trains at once or just convenience when you are at opposite ends of the layout. A supply for point motors etc. to avoid the operating pulse interfering with the trains and another for lighting. This latter is a fairly constant load so could possibly use a spare 16V AC tap on the train supply as long as it is a separate winding and not just across the train supply.