This is specific to only how the wires are connected to the hubs:
Shimano and SP. I think you can treat Shimano and SP as the same, although I believe that all newer Shimano hubs have one connection grounded to the fork and SP does not. My first dynohub was an SP that I bought in 2013, I moved that around between three different forks. For simplicity I had wires and a plug zip tied to the three forks. At that time nobody sold an SP in USA (I ordered mine from Taiwan), so I was quite happy to discover that the Shimano plugs were interchangeable with it as I could buy those connectors.
Son. Clearly looks different and I have never used one. Now they also make one that uses each fork blade as a connection, you need a fork that is built for it. So, there are two Son current standards.
Panasonic. The plug looks similar but different from the SP and Shimano ones. I have never seen one, thus I am clueless.
https://www.somafabshop.com/shop/product/panasonic-dyna-hub-6v-3w-qr-rim-brake-4420Sturmey Archer. I have no clue if the plug is the same as one of the others or not.
https://www.sturmey-archer.com/files/catalog/files/170/MANUAL%20-%20DYNOHUBS.pdfGrounding to the fork. Since my first two hubs were SP, I had learned that the hub was not grounded to the fork. Then I got a great deal on a used wheel with a Shimano hub, and it took my hours to figure out that my hub and my light were both grounded to the fork, but with wires reversed it did not work. Thus the hub worked on one bike but not on another. That was how I learned that Shimanos are grounded to the fork. The link to Sturmey Archer above, the hub connection looks very similar to Shimano, I suspect that it is also grounded to the fork.
Vintage. And of course anything vintage could be different. The Sturmey Archer hubs that I worked on in the 70s when I worked at a bike shop are clearly different than the current ones.
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I am not researching this further, anyone else that wants to, go ahead. Of these, looks like one does not start with an S for PH. A few other misc notes:
Anyone that is trying to figure out if they should get a dynohub or not, they usually are not sold with a skewer.
The ones I bought new, I built up the wheels so they were quite inexpensive because the price difference between a complete wheel with or without a dynohub is only the cost of the hub minus the cost of the regular hub. But, if you are looking to upgrade and get a new wheel, that is when they get much more expensive.
So far the transition to through axles is slower for dynohubs than for frames and derailleur hubs. I built up another dynohub wheel last spring, I considered futureproofing it by building a through axle hub with quick release converter, but it was much more expensive than a conventional hub, so that is what I decided to build.
Since dynohubs are mostly used for lighting, if anyone is interested I documented how I wired my rando bike for lighting on a different forum, at this link.
https://www.bikeforums.net/electronics-lighting-gadgets/1228845-wiring-up-dyno-powered-lighting-system-usb-charger.htmlThere was an article almost a decade ago that provides some very good info on some of these hubs if you are interested, at:
https://www.cyclinguk.org/sites/default/files/document/migrated/publication/feature-hub-dynamos.pdf