I had the idea after I read this blog entry on Hackaday. After watching the video I did some research on other people who build EDMs. I found some papers regarding the topic and the PDF of the book that the blog entry is based on, but no concrete build and design instructions. So the first phase will be designing the spark circuit so that the work piece and electrodes don't fuse together and everything is ready to be put into a CNC machine. In theory we only need to remove single spots in a 35μm thick layer of copper, therefore we only need a relatively low power device. But we still need to break down the electrolyte and therefore 60 to 100 VDC. Also we must be able to control when to spark. The use of switches/relais is non-practical beacuse of the noise and the high probability of spark inside the switch and therefore power dissipation.