I plan to build samples of both the George Stilwell BCD Circuit and the Rob Paisley Circuit to choose which I like best to control the Kato Unitrack (single coil) turnouts on the N Scale layout I am planning. These are capacitive discharge circuits, neither with transistors. I'll be driving 24 Turnouts. Both circuits require 12 VDC, but I have two choices for power sources and need help deciding which is best. Can someone help me decide? One option is a 12 VDC 500 mA "wall wart" transformer which I have. With no load, it produces 16 VDC. I'm thinking that it's probably unfiltered and will need an inexpensive 470uf electrolytic capacitor added to the output. The other option is a Hewlett-Packard printer 18 VDC 1.1 Amp power supply which I have. With no load, it produces 18.5 VDC and I assume it produces "clean", filtered power. I'd then connect its output to a "buck converter" that I'd need to buy to get the needed 12 VDC. Which is my best bet for circuit longevity and reliability? I know that when these two sources are connected to a load, the output voltage will drop. I'm thinking that the H-P/Buck Converter choice might be best, but it also might be overkill for such relatively simple circuits. Any advice is appreciated!