A caveat with higher current capacity power supplies (esp. replacing one kind of battery chemistry with another) is their internal impedence characteristics may vary, and if the electronics being run assume a certain impendence, things may go awry. A specific case is replacing alkaline batteries in some electronics that depend upon the internal current-limiting impedence characteristics of alkaline batteries. In those electronics, if you try to use NiCads or NiMH batteries, the device sometimes misfunctions. (Alkaline batteries have a (much) higher impedence than NiCads or NiMH batteries, as a result alkalines don't like high-current loads like digital cameras. I think certain older film-camera flashes were among devices that don't repond well to NiCad/NiMH batteries).
As far as using a higher current power supply on an AP, I don't think this will be a problem. For long runs it may be necessary to use a higher voltage (but same or slightly higher current) power supply than the original in order to overcome the voltage drop over the CAT5 run. If you use a power supply that puts out enough voltage but not enough current, the voltage will drop (to some degree) in order to make up for the current shortfall (basically you have a brownout). You can find voltage drop calculators using Google. Most CAT5 is 24 gauge wire. The AP should have an on board voltage regulator to bring the incoming voltage down to whatever the chipset needs, so being a few volts (say < 3) above the specified voltage at the end of the 300 foot run likely is good enough. If you open the AP and identify the regulator IC (possibly a three-legged 7805 or 7812), you can then look up its spec sheets for its acceptable input voltage range. That said, the closer your input voltage is to the regulator's output voltage, the cooler the regulator will run and the happier it will be. -hk At 09:43 PM 2/4/2006 +0100, you wrote: >Increasing the Voltage beyond the specifications will kill the radio. >Putting a higher power - (current) PSU shouldn't hurt the radio. The radio >will 'draw' the needed current only. >The power consumption if assumed constant, > >P (Power) = I (Current) x V (Voltage) > >----- Original Message ----- >From: "Brian Rohrbacher" <[EMAIL PROTECTED]> >To: "WISPA General List" <[email protected]> >Sent: Saturday, February 04, 2006 9:34 PM >Subject: Re: [WISPA] OT amps and volts > > >> It's not actually mine. It's another's from the list. We were talking >> about it. But I am sure that on my 230 ft run of cat 5 that I had to >> replace an 18v 1a with an 18v 2a to get the radio to stop rebooting. The >> individual I was talking to thought if you up the amps it will kill the >> radio. I thought if you up the volts it kills the radio. Who is right? >> >> Well, actually I know what the cat 5 is. It's comscope 25 pair. >> Which brings up another question. Who does this? Run a single bundle of >> 25 pair up towers and use punch down blocks. Any issues with this? >> >> Brian >> >> Sean S gayle wrote: >> >>>Brian, >>> >>> I'm normally a lurker, but maybe your problem is in the 300' run of >>> CAT5. >>>What kind is it? You may be getting signal degradation which is causing >>>the >>>sporadic radio behavior. >>> >>>Sean >>>JohnnyO's evil twin >>> >>>-----Original Message----- >>>From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On >>>Behalf Of Brian Rohrbacher >>>Sent: Saturday, February 04, 2006 2:01 PM >>>To: [email protected] >>>Subject: [WISPA] OT amps and volts >>> >>>I'm a little confused here. I'm working on a 300 ft run of cat5 and have >>>a question. The radio is acting sparatic. The power supply has already >>>been upped from a 18v to a 24v. Both 1 amp. Will it hurt to put a 24v 2 >>>amp power supply in? If I "over do" on amps or volts, what blows a radio. >>>One or both? I seem to remember being told that a radio only takes what >>>amps it needs, so putting a higher amp power supply in won't hurt, but if >>>you put too many volts in, that will fry them. Please clarify me on this. >>> >>> >> >> -- >> Brian Rohrbacher >> Reliable Internet, LLC >> www.reliableinter.net >> Cell 269-838-8338 >> >> "Caught up in the Air" 1 Thess. 4:17 >> >> -- >> WISPA Wireless List: [email protected] >> >> Subscribe/Unsubscribe: >> http://lists.wispa.org/mailman/listinfo/wireless >> >> Archives: http://lists.wispa.org/pipermail/wireless/ >> >> > >-- >WISPA Wireless List: [email protected] > >Subscribe/Unsubscribe: >http://lists.wispa.org/mailman/listinfo/wireless > >Archives: http://lists.wispa.org/pipermail/wireless/ > > -- WISPA Wireless List: [email protected] Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
