Lighting wiring

[DavidEnghauser]

Thanks to many of your suggestions I have completed the DCC track wiring buss, droppers, etc. As I posted earlier everything runs well. I will now be putting in scenery, buildings, etc. My current question is:

Can I run a two strand wire under the baseboard and basically do drop down wiring for the lighting to this buss? I have a small 9V transformer that I would attach the lighting buss to. I will be using LED lights so they won't be drawing much current.

Thanks for your help,

David Enghauser in Richmond,VA

[DavidEnghauser]

Correction: I have a 12 volt, 2 amp transformer, which will power 100 LED lights.

[Steve M]

The simple answer is, yes you can. But it is rarely that simple.
To start with, check that the total current drawn by all the LEDs is less than the output amps of the transformer. Personally I would limit the lighting transformer to 1 amp for safety. If the transformer puts out more than that you can split the feed into separate 1 amp feeds using self resetting circuit breakers.
Don’t forget each LED will need a resistor or they will blow.
Even on 9v you may find LEDs are too bright so you can either use a power controller to reduce the voltage or experiment with resistors of different values. Be aware that LEDs won’t work if the voltage drops below a set value.

[DavidEnghauser]

Thanks Steve,

I have purchased the LEDs for the buildings from a supplier here in the US that have a resister built in. The platform lights will be from Gaugemaster and they come supplied with a resistor that is soldered on.

Where would I find self resetting circuit breakers?

[Brian]

Correction: I have a 12 volt, 2 amp transformer, which will power 100 LED lights.

Hi
A 2.0Amp power supply will feed around 200 or more LEDs when their series resistor is of a reasonably high Ohmage value. 1000 (1K0) would on 12 volts give most standard LEDs around 10milliamps (0.01Amp) each. You can get some LEDs that work on 2ma (0.002A) You just need to know their spec.
This LED resistor calculator web site is good to use... http://led.linear1.org/led.wiz

Your lighting Bus idea is fine, but do remember that whatever is tapped off the bus pair there is no control over them. You therefore can't turn On/Off individual lights etc easily. SteveM makes a good suggestion of splitting a 2.0Amp power supply into two sub bus pairs, each protected by its own 1.0Amp circuit breaker or a fuse. Self resetting CBs are easier to use as you don't need a supply of spares as you may well do with fuses. Examples... https://www.railwayscenics.com/self-res ... p-415.html or https://www.rapidonline.com/Catalogue/Product/26-1110

Next, be sure what you have as a power source is the best option..
Transformer.. Converts mains power voltage to a low voltage and should ideally isolate the two. AC in and AC out. Note; some transformers can provide the same output volts as the input 1:1, others can increase the output volts (Step Up). Not all transformers isolate secondary from primary either. An Auto transformer is one such that doesn't isolate. In the main in model railways we need a step down isolating transformer
Rectifier.. Converts AC into DC can be used in conjunction with a transformer to give AC input and DC output at a lower voltage than the input.
Power Supply Unit (PSU).. Often a plug-in device with a built in transformer and can also have a built in rectifier.
Regulated PSU Often a plug-in or 'brick' style power supply providing a stable output under varying loads. These are best used for layout lighting as they remain constant and are DC. LEDs work best with a stable DC supply, though they can be operated on AC too and you can now obtain AC LEDs!

[Steve M]

This is the sort of thing you would be looking for. This one is very expensive but you should be able to source similar for a better price. I think I used to get mine from Maplins (before they went bust) for about 50p each

https://railsofsheffield.com/products/1 ... it-breaker

While you are looking have a look at these voltage controllers

https://rover.ebay.com/rover/0/0/0?mpre ... 2692035870

[DavidEnghauser]

Brian, Both Railway scenics and Rapidonline show that the circuit breaker is discontinued. Rails of Sheffield has one from Gaugemaster. Since they have 2 prongs, how do you wire them in? Would I put one on the beginning of each circuit?

Keep in mind I am a complete novice with electricity. However I did do well enough to wire and solder the track in place. I need step by step instructions.

Thanks again.
David

[Steve M]

They are designed to fit on a PCB but I soldered the positive wire from the PSU to one terminal and then took a wire from the other terminal to one side of the bus. The negative wire from the PSU goes straight to the other side of the bus.

Untitled by Steve Mumford, on Flickr

It’s not pretty but mine were mounted on a board to stop any stress on the wires. The photo shows an 8 amp PSU split into eight 1 amp supplies.

[Brian]

Brian, Both Railway scenics and Rapidonline show that the circuit breaker is discontinued. Rails of Sheffield has one from Gaugemaster. Since they have 2 prongs, how do you wire them in? Would I put one on the beginning of each circuit?

Keep in mind I am a complete novice with electricity. However I did do well enough to wire and solder the track in place. I need step by step instructions.

Thanks again.
David

Hi
As you're USA based I assumed you would like to know what self resetting Thermal Circuit Breakers were hence the links. I guess there are US electronic suppliers who would stock similar? An internet search should reveal them ...Search '1.0Amp Thermal Circuit Breakers' Brimal in the UK have them... https://www.brimal.co.uk/over-current-c ... 0-amp.html
They are wired in series into the positive or one feed wire from the power source (AC or DC). So the power source has two output wires and the CB connects into one wire of the two. On DC it would be the positive wire on AC it doesn't matter too much. Output from PSU to one CB tab, other CB tab to layout/lights. Other PSU wire goes straight to the layout/lights.