Check also similar project Simple EVSE-WB
This project was started in 2013 in cooperation with GWL company. The goal was to create minimalistic solution which would allow faster charging of Peugeot iOn since these cars are equipped with 10A cables from the factory. Some moths later we introduced small board which was possible to be built inside the J1772 connector including power relay (20A) and AC/DC (12V) power converter.
Please do not expect anything like RCD protection or big shiny displays showing charging status including current which was set. Using this hardware you can basically make a cable that has 2 more wires and tells your car - please charge, that is all I want.
All the documentation for this project is currently hosted here: