Hydra II EVSE v3.1 schematic

Here are the latest schematics of the Hydra II EVSE variant.

In the upcoming 3.1 board, MC34063 DC-DC converters will replace the two integrated modules that were present in previous designs. Also, the "Sziklai pair" switching transistor architecture has replaced the previous Op Amp and switch chip designs for the pilot generator. Lastly, provisions are in place for a future relay test input connector. The purpose of that is to be able to detect the presence of AC power on the J1772 hot lines for each car. If power is not present or absent when expected, then that's a (potentially serious) error.

I have what I hope is a finalized board design, but wish to check the layout of some of the new parts against what I get from DigiKey. Once that's done, the boards will be ordered from OSHPark, and then two weeks later, the prototypes will be built.

Similar changes have been made in preparation for the v2.3 board as well (which is the original "splitter" variant of the Hydra). If the changes to v3.1 work, then the process will be repeated for v2.3 as well.