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Although the original housing and cover are obviously not cleaned up at all, I did a trial assembly of one of the two prototypes I’m building and experimented with different methods of attaching the connectors to the daughterboard underneath. It was impossible to design the main board so that the connectors ended up where they needed to be so a daughterboard remaps them. I have already designed an electrically far heavier duty board but I need to be sure that the circuit itself is viable before making it.

The main limitation of course is that it is negative ground so once tested and if it works, I’ll have to look into how to design one that is positive ground. Ideas for making it switchable were toyed with but there simply isn’t enough room to do that but switching 6v to 12v was fairly straightforward..

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Awesome work Don!

Thank you! I am doing this mainly as an exercise for fun as they would be far too costly to produce a few at a time. I know that no one would pay anywhere close to what this one cost!

I do need someone with a 3D printer and the ability to design and print some black plastic insulators for the openings where the connectors come out, mainly to add some strength to them and to better emulate the original (although I have several and they're each different so I am not sure what original is!). As it is, pushing down on the screws to tighten them would put considerable strain on the daughterboard. Also some kind of back cover to keep out water would be nice but I may opt for something pourable to seal it really well if I can find such a product.

Then there is the matter of heat. If this work at all, I expect that there will be heat to expel but there is nowhere for it to go, especially if the back is sealed.

One concern is whether PCB traces can handle the current so the next design will take that better into account. On this one, I originally tried to make multiple traces across up to four layers where possible to spread out the load but the design was not only difficult to follow but also the boards with inner layers were quite expensive to make.

Also the steel connector tabs on this design are each different which made them quite costly to make but the yet-to-be-made redesign has them all the same.

Obviously this is the Delco-Remy design but after I had designed and made it, I finally got an original 1956 Autolite and see that it is much narrower so I'll have to somehow try to compress the design and I have no idea how I am going to do that as it's tight already!

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Maybe RTV silicone?

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Can you CAD them yourself?

I wonder if a Gate turn-off thyristor (GTO) would work well for polarity-independent regulation without having to swap arm and bat connections depending on polarity. The problem is that in industry these have been replaced with IGBT's or TRIAC's in most applications. The problem here being that IGBT's don't conduct in both directions, and TRIAC's don't turn off once they are on (they are designed for use with AC where they will naturally turn off every 1/2 cycle). So GTO's are hard to find.

Unfortunately I would need someone to do the actual design as I am not an electrical engineer and unfortunately I do not know 3D CAD either. I work with a company for some of my 3D scanning projects that can also do the necessary 3D CAD work but he's quite expensive! Back in my journeyman prototype machinist days I did 2D CAD but not 3D and that was decades ago. I run Linux now and there are CAD applications but most seem quite unwieldy and not too user friendly.

For the sealing, I had thought of silicone but I was picturing something that actually hardens. Of course, it has to be completely non-conductive too but most products I've looked at don't mention that in their specifications.