I normally carry a small hand pump with me on the bike in case of puncture. My emergency plan consists of the goopy stuff that one sprays into the flat tyre but one still has to get air in there too and my lungs aren’t up to the task. It is attached to the crashbars in a cradle made for just that purpose.
It has served me well but I felt the need for something more professional for use in the shed. I now have something…

My dear wife, having heard my lamentations over this state of affairs, bought me a mini compressor from Black & Decker for Christmas. A compact little machine which can be driven by mains electricity or from a 12V take off. It is a little cumbersome to take on the bike but for use in the shed it is superb. I can also carry it in the car, so it comes with me on longer trips. One never knows…
The air line and the electrical lead fold nicely away under the top cover and the 12V line is coiled up and packs away in the back of the body. The required pressure can be preset on the front of the machine. Very useful in case of emegency. Just to give a sense of size, the box measures 12″ x 6½” x 7½”. Here it is:

This is all very well but I also needed a compressor for other simple jobs like spray painting, a washer pistol, an air gun for dusting off and so on. Not having a tank that i could pressurise, I needed a real compressor. But not too big. The shed isn’t that large. I found one the other day. From Stanley. It will compress air up to 8 bar and will drive a rattle gun. Again, required pressure can be preset on the machine. Electrically driven, this one does what I require of it and is still very portable. I had to buy attachments for it but these are not expensive. A spray gun, a washer, an air gun, a tyre pessure gauge and air line all came in a kit at a very reasonable price.
I reckon I’m covered…