Power over ethernet problem

[benjenn]

I work for a databasing company which recently did a bid on a wireless internet/network install. Our wireless consultant gave a bunch of bad info and left us with $12000 worth of "unusable" equipment. We have a cisco catalyst poe switch and a bunch of linksys wrt54gs routers. We found some 3Com devices for their IP Phones that will initalize the switch but they output 24V 1.2A dc. The rating for the routers is 12V 1A dc. Is there any semi-easy way to get the 12v 1a we need from these devices.

 

[Oznog]

I work for a databasing company which recently did a bid on a wireless internet/network install. Our wireless consultant gave a bunch of bad info and left us with $12000 worth of "unusable" equipment. We have a cisco catalyst poe switch and a bunch of linksys wrt54gs routers. We found some 3Com devices for their IP Phones that will initalize the switch but they output 24V 1.2A dc. The rating for the routers is 12V 1A dc. Is there any semi-easy way to get the 12v 1a we need from these devices.

Not really easy. A reg can readily get you 12V, but it has to dissipate 12 watts for a 1 amp output. Big ass, majorly hot heat sink, potentially failure-prone to run a reg that hot. I'd use a resistor in series with the reg's supply to move some of the heat away from the sensitive reg. But the simple answer is to just go on eBay, surplus catalog, or wherever and get the right one. You don't want hacked together power heatsinks scattered all over an office setting.

 

[Sebi]

Maybe a switching buck regulator can solve this problem. National LM2576 in 8pin dip can handle 1A.