On Thu, 04 Sep 2003 17:57:24 PDT, [EMAIL PROTECTED] wrote: >. I've been using "my standard" for 3 years now to power outdoor >ethernet devices - but all I do is put 48VDC on the spare pairs and use a >standard dc/dc converter to create either 5VDC or 12VDC (or both) inside the >device. .... >. Because of the low power requirement for 802.11 >hardware, even linear regulators work with tiny heatsinks. This is >fair game for any load up to 1A - above that range is where DC/DC >converters are really required.
Don't get me wrong, this is an excellent post, but I don't know of many 802.11b cards that are less then 300ma and most of the bridges are in the 500ma to 700ma range. My Dlink 810+ bridge, I just measured it yesterday at 500-650ma at 5volts. So with a linear regulator, you looking at it to drop 43 volts to come up with 5 volts (48-43=5). At 500ma current your looking at a heat load of 21.5 watts..... no tiny heatsink I know of can handle that without a meltdown. But your practice is a sound one (using switching regulators). I might even asked if you took it a step further and just ran raw AC up the lines (like from a doorbell transformer) and did the filtering and regulation (with a switcher) at the ethernet device? -- general wireless list, a bawug thing <http://www.bawug.org/> [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless
