I had the 400 watt PC power supply on hand already.

I plumbed it in to the buck converter and discovered that I had ordered a 1.2v minimum buck converter, perhaps I shouldn't have ordered it quite so early in the morning.

For my very small experiment with a thin brass tube soldered to a corner of a PCB, and a 1" x 3/4" copper tube, I had too little surface area for 1.5v battery and a 1.2v buck converter.

Solutions include increasing surface area, decreasing voltage

I threw a voltage divider on the output of the buck converter (I could have saved 16 bucks if I had thrown one on the AAA battery too, but... I didn't.)

I suppose that makes fail 4