How to run under-cabinet lights cables (18AWG) in walls so that the junction box is neither apparent under the cabinets, nor in the cabinets?

Question

Context: I am remodeling my kitchen and currently working on wiring under-cabinet lights. In my research, I find that I need:

1. a power source, which can on one of the 2 counter receptacles circuits
2. a LED Driver power supply 120v to 24v
3. 18 AWG cables to run from driver to LED strips or between strips

Problem: I cannot find clear details of where to place the junction box so that it is not apparent from under the cabinet and in the cabinets.

What I understand: If I want the cables in the walls, so that they are not apparent, I will need a junction box when they come out of the wall to the LED strips.

Question:

1. How to run under-cabinet lights cables (18AWG) in walls so that the junction box is neither apparent under the cabinets, nor in the cabinets?
2. Are junction box a must have for low voltage LEDs?

Answer 1

Junction boxes are not needed. I ran mine inside the cabinets stapled (correct staples) against the front of the cabinet before putting the counter tops. I also used small magnetic read switches that would turn on a relay to light the LEDs, again stapled to the inside of the cabinet faces. This mounting allows me to access, difficult but doable, it if I ever have trouble. I have a basement so I simply came up through the floor. On the uppers I came down from the attic, it is a ranch home. I used some of the Arduino module relays and modified the opto circuit for 12V. The lighting I used was 12 VDC. This was for the in cabinet lighting, I did exactly the same thing for the under cabinet lighting. All of the lighting was strip LEDs on aluminum in aluminum rails held in place with clips.

If you have the drywall off consider running a plastic coudoulet about 2" from the attic to basement or crawl space and cap the ends. This can make changes easier later.

Answer 2

We just had under cabinet LED strip lights installed. We had the transformer/power supply mounted behind the top drawer of one of the cabinets. This is fairly open so should provide enough air circulation to prevent early failure of the transformer.

The 18 gauge wires for the LEDs were then run behind the drywall (did require some drywall work) up to the cabinets and brought out through a 1/4" hole in the back corner of the underside of the cabinet, and then run over to the LED strips.

You can't seen any of the wiring unless you poke your head under the wall cabinets. Nothing is visible when standing or even when sitting in a chair.

Here's a picture of the the wiring under the cabinet. The brown tape is temporary. The circled switch controls the LED strips.