Are they incandescen'ts, LED's, or a combination of both?

John C

You have to add up the amps being loaded on the power pack. If just for building lights (depending on the size of the layout) you should be OK for buildings with LED's. I use a ​separate​ power pack for all my switches. Loading the lights and switches on the same power source is asking for problems. 

The bulbs are incandescent type. no leds right now.

I think this may be too much for the power pack i have.

If you have the incandescent lamps all on their own separate circuit then a transformer of correct voltage and sufficient amperage is all you need. Lamps don't care about AC/DC or tightly regulated voltage.

Assuming 12v lamps... this Radio Shack transformer will supply 3A.

You can also buy regulated power supplies on eBay at real reasonable prices. Up to 50A output are available. 50A will drive an almost unlimited number of small modeling light bulbs.

By comparison, the MRC Tech4 web page says the output is 18.5V at 17-20VA if I read it correctly. That means it can supply approximately 1A.

Thanks for the info Alan, I will check into that radio shack tranformer.

Ask a simple question get a long answer:

I use Christmas tree lights for my structures.  You can buy a string of 50 for about $2-$3.  Even less right after Christmas.

The lights run on 2 1/2 volts.  My layout is still block control using MRC power packs.  The AC accessory circut is about 20 volts.  Thus, connecting 8 lights in series works.

Another source I've used, particularly, on modules, is abandoned cell phone chargers.  Measure the output, divide by 2 1/2 and you have the number of lights to connect in series.  The disadvantage is that you need a 120V input source for this solution.

Xmas Lights! Brilliant!!!!

And yet again how the obvious jumps up and bites one in the a$$!

This is why I love this site. so many good tips from great modelers. I take it you get the Xmas lights that stay lit when one goes out.... That could be the Nghtmare before Xmas. LOL.