Hi all,
As it seems some Ethernet runs are planned for today, I was thinking about
power distribution also for the Beagle Bone Blacks (maybe not Blacks but
anyhow) recc'd by Marc to control electronic access at each door needing it.
Stringing extension cords & wall warts from ea. BBB - door set is both not
code-worthy (if an inspector really wanted to bust our balls since
'permanent' extension cords are called out), multiple AC>DC conversion
is also power-inefficient, prone to power loss/unplugging & and may require
further electrical work to bring outlets closer to some doors..
Since I understood that BBB's don't accept Power over Ethernet (PoE) I was
considering central low-voltage power distribution through a single
Variac-type DC power supply, DC PDU, PowerPole connectors and the zipline
of appropriate gauge for the runs to deliver ~5VDC at the BBB endpoints (I
have done this before).
However (even if it is not as power-efficient) if we are injecting at
Sudo's racks it seems we could use Ethernet for power if
we inject 12VDC PoE, then break it out at the end to a cheap 12>5VDC
adapter which could in turn feed the 5VDC port on the BBB's - check out the
last post of:
https://groups.google.com/forum/m/#!topic/beagleboard/nrRZJkCWQa0
If we're running the thicker-gauge pairs in cat6 (compared to Cat5(e)), we
might be able to get away with 5VDC injectors but probably the injection
point would have to be more centralized within the building than the racks
in sudo room - like in the basement furnace room e.g., which makes most
sense to me as the central distribution point for Ethernet runs around the
building, due to it's centrality, the ease of running
into/along ducting/registers, proximity to the basement,
perimeter crawlspaces, the ease of lateral runs through the basement, etc.
Love
David