Decided to respond here since it's directly related. I've had another project come up which uses this circuit, so I thought I'd write something up for it.
I have a lightbox that is pretty bright and wanted to add dimming to it without modifying it too much. I decided that I could likely put a dimmer box in line with the power cord. There is a pigtail coming out of the lightbox with a plug on it. And the AC > DC converter has the other plug end on it. I figured I could get a pair of jacks and have the box in the middle. The specs aren’t too bad at all. 12V at 1A max based on the wall-wart. So that was my design goal.
I’ve already built of one these circuits just for fun/testing. But this came up and was the perfect time to break it out again. I changed out the MOSFET I used last time for one that can reliable drive more current. I think I went overkill, but I don’t have many options for heat sinking I don’t think.
I choose the project box kind of at random and had to get the size of the protoboard to work with. To do that I looked at the box’s datasheet to get the dimensions and then transferred them to paper to mock it up. From there I cut it out and traced it onto the protoboard that I have. That gave me the number of holes I had to work with.
From here I decided I needed some help laying out the circuit to see if it would even fit. I could have done it by hand, but I decided to look for some software help. I found some nice software (really easy to use with some nice features). It’s called DIY Layout Creator, located here.
It worked out great and I’m able to fit the circuit with protoboard in the project box. In hindsight, these steps should have been reversed. That being said, there isn’t much to this circuit so it isn’t so bad this time.
And that’s where I am now. I’ll be adding more when I get to it.