ShiftPlusOne wrote: ↑
Mon Aug 20, 2018 11:39 am
Is it intended that the schematics for the PoE HAT will be published ?
I'm not aware of any plans to do that at this point. Is there any information in particular you're looking for?
I was really after 'the full power regulation circuit'', but 'the whole lot' would satisfy my curiosity.
I was speculating whether the HAT could be used to provide PoE for Pi boards other than the 3B+, even other products. That would obviously require additional hardware, an additional ethernet jack from which PoE could be extracted at least, and perhaps modifications to the board, but that might be worth it to some.
I was also wondering if it could be used as a step-down regulator for non-5V supplies, what it's operating envelope would be, what limitations there were, whether it could be modified for that use.
Obviously knowing what the actual circuitry is and components used would help answer those questions.
I was hoping the full schematic would be published to save having to purchase a board and reverse engineer it myself, or having to wait for someone else to do that. I would rather have an official schematic than something from a third-party, and would prefer not to have to do the reverse engineering myself.
Many thanks for the other clarifications. One question I hadn't asked ...
If power is supplied over PoE and through the micro-USB; which does the Pi use for its power ?
How the HAT handles voltage mis-matches and prevents damaging an incoming micro-USB supply when both are connected is one thing which intrigues me. The 3B had the 'ideal diode' Q3 but the 3B+ doesn't. Having the circuit diagram could answer that. I'm happy to take a written explanation though.