[Soekris] POE maximum voltage?

Dave Parker daveparker01 at gmail.com
Wed Mar 28 02:35:10 UTC 2007

I guess I was being overly optimistic a bit on the "really easy to
answer" part; two people have recommended that I add some sort of
regulation to the voltage to keep it below 56vDC.

I'm kind of (not just kind of) out of my league on this, but I've been
thinking then that the circuit described in the "Simple Voltage
Stabilizer" section of this page:
http://en.wikipedia.org/wiki/Voltage_stabiliser might do the trick? My
understanding is that it would "regulate" voltage only in as much as it
would keep it from exceeding a reference voltage, which I would probably
select as 54vDC to be safe.

Do people from Soekris read this list periodically? I was kind of hoping
for an "official position" on the topic. Minus that, I guess I'll have
to see if I can build one of those circuits.

Dave Parker wrote:
> I should mention that the battery bank itself is nominally 48vDC.
> Dave Parker wrote:
>> Hello
>> I have what I'm guessing is a really easy to answer question:
>> Is 59.2vDC an unacceptably high voltage to send through a POE injector
>> to a net4526?
>> I've salvaged a bank of lithium batteries and charger from an electric
>> scooter, and while I'm suspecting that there are enough amp hours there
>> to run the board for "a very long time" without charging, I'd like to
>> use those amp hours for other things, so I'd like to use the charger
>> while the board is in operation. The charger's logic  appears to have
>> voltage top out at around 59.2v, and maintenance is around 56v.  The
>> former scares me a bit.  Will the board tolerate that?  Is there
>> something I should add to the circuit to protect the board while the
>> charger is operating?  The cat5 run from the injector to the board is in
>> the 5-8' range.
>> I've tried finding a concise answer to this question with some extensive
>> googling to no avail aside from two documents that mention "absolute
>> maxium voltage = 68vDC.  That's not enough to make me feel secure about
>> my magic smoke, hence... I ask :)
>> Thanks in advance,
>> Dave Parker

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