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Paul Sutton wrote: > marcus turner wrote: >>> Seems sensible, no doubt we could setup an AP in a similar way..? >> I have a spare cable router that could be used as an ap for this >> project. It runs on 4.5v, 1.5A > I have a few voltage regulator chips, if anyone has any circuit solder > boards (the pre drilled boards with tracks,) and a soldering iron, you > may be able to come up with something, mini power unit for example. Hi, Bit late in the discussion but... Any idea of what you want to use as a power source? This is always a PITA, Probably a 6v *sealed* lead acid (eg gel battery) is as close to optimum as you would get. If you use a good old 12v you have to loose 12-4.5v = 7.5v across your regulator and at 1.5A that is 7.5*1.5 = the best part of 12W as pure waste and although you can stick a big heat sink on its not a great solution. if you need more that one hub then the power wasted gets stupid. A more optimal solution to the voltage conversion is a DC-DC converter, although more expensive the efficiency is MUCH higher that a regulator solution. Also bear in mind that standard 12v lead acid, although cheap and easy to get from scrap yard etc, they don't like being used in this way particularly. You can't deep cycle them and you can only draw off 25% capacity before you reach the magic 12.4v threshold and irreversible sulfication begins. If you can keep them topped up all the time then they are fine. The alternative is gel batteries, as mentioned, (sealed lead acid) which are designed to be deep cycled (as used in UPS's and other backup equipment) but expensive by comparison but are also available in 12v or 6v. Anyway if anyone does start building something and needs some help with electronics let me know. -- Robin Cornelius http://www.byteme.org.uk
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