My prototype motor uses four of these circuit's, positioned 90 degrees apart around the rotor, and all connected in parallel. You can use just one reed switch to switch all four transistors and coils but it is more load and the reed switch does not hold up for very long. In fact, either way, if you use small reed switches, they will get worn and start to stick. I have bought larger reed switches but I am also working on an electronic switching version of this, although that is easier said than done. I have worked on this for a few months now so I have tried very many things and have not managed to match it with electronic switching yet. Limiting the current passing through the reed switch does not necessary increase the length of its operational life, besides which, doing that produces less radiant energy.