12v down Cat5 again

["David Chapman" <david@xxxxxxxxxx>]

Yes I know it's been discussed before but I can't find any consensus on the
figures.

Although it has batteries my WM968 weatherstation needs 12v - mainly to
power the backlight behind the LCD display which comes on when you touch
it.

Got the meter out and it's 12v and needs 10mA most of the time increasing
to
150mA for the 10 seconds or so when backlight is on. Although it's Cat5 I'm
sending good old RS232 down it to the Com port of the PC - I think just
pins
2, 3 and 7 so should have potential to double up the available pairs to
supply 12v if necessary, distance is about 10 metres.

Be great to feed the 12v from node zero and avoid the black box. I would of
course put a fuse in to protect the cable but is an occasional 150mA asking
too much ?

David C

ps I was talking about RS232 during Christmas after the Spitting Image
tribute with some friends who don't go back further than USB. Anyone else
remember the Spitting Image tribute song to the "RS232, RS232, RS two
thirty
two interface lead" ?