[KAT5] Remote KAT5 Power over CAT5.... WAS: KAT5 Power over Ethernet

["Keith Doxey" <kat5users@xxxxxxxxxxx>]

Hi All,

Subject changed to clarify the situation.

KAT5 does not use ethernet and the term Power over Ethernet is not really
applicable in this case.

KAT5 uses all 4 pairs in the CAT5 cable so there is no capacity for
carrying
power on the same cable but it is possible to use another cable to carry DC
power.

The simplest way to do this is to cut a patch lead in half and fit a 2.1mm
DC power plug to one half and a 2.1mm DC power socket to the other half.
This can than be used to extend a power supply over a CAT5 cable.

I would suggest using the BROWN/White pair for carrying power as the Blue
and Orange pairs are used for phone lines and the Orange and Green pairs
for
ethernet. It makes sense to choose a pair that is less likely to cause
damage to other equipment if incorrectly patched. If you decide to do this
then please make sure you dont get the KAT5 and ower leads the wrong way
round!!

With regard to driving multiple KAT5 units from one supply, this can be
done
as long as you pay attention to the total load.

A KAT5 Receiver can use upto 100mA so three could be powered from a single
KAT5 PSU.

A KAT5 Transmitter can use upto 150mA so only two of these could be powered
from a single KAT5 PSU.

If you have a power supply other than the 300mA KAT5 PSU's then you can do
the maths yourself to work out how many units you could power.

There is one caveat to be aware of.....

.... KAT5 uses balanced transmission for distribution of its Audio and
Video
signals. The main benefits of balanced distribution are high noise immunity
and the elimination of ground loops as the signal does not use ground as a
reference.

By using a common power supply to feed more than one unit you will be
creating a common reference point between units which can cause ground
loops.

With several transmitters running from a single supply this should be a
problem as they are probably all being fed from equipment in the same
location.

Likewise if you had 2 or 3 receivers connected to a TV or Plasma screen
they
would also have a common reference to the display device.

Where problems COULD arise is when you feed both ends of a KAT5 circuit
from
the same power supply eg


Digibox----KAT5TX----------------------KAT5RX---TV


PSU---------------------------

because the Digibox and TV will already have a common reference between
them
from the aerial distribution system and the power supply cable then forms a
loop.

If ground loop problems do occur they will be noticeable by either a dark
bar moving slowly up or down the picture or a constant hum on the audio. If
this does occur you will need to use separate power supplies

Digibox----KAT5TX----------------------KAT5RX---TV

PSU1

PSU2--------------------------


I hope that clarifies it for people.

Regards

Keith



> -----Original Message-----
> From: Tony Butler [mailto:lists@xxxxxxx]
> Sent: 11 November 2004 14:15
> To: kat5-users@xxxxxxx
> Subject: RE: [KAT5] KAT5 Power over Ethernet
>
>
>
> That's what keith is suggesting.
> I have typically one PSU per kat5 "cluster"
> Eg, there are 3 kat5 units near the tv driven by one psu, 5 or 6 on n0
> driven by 2 psu's I think and so on...
>