Except SmartBridges went away from the standard and only use one wire for the ground side (other one is used for reset line on injector).
JH ----- Original Message ----- From: "Brian Winter" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Friday, November 07, 2003 2:04 PM Subject: Re: [smartBridges] 18v power? > They can't "certify" this. It depends on the cable you use and how good the > regulated supply is. Assuming a psu man enough for the task, Cat5 cables > will be similar so as a guide: > > Woodhead outdoors cat5 FTP and UTP 24 awg solid has DC resistance of 150 > ohms/Km (at temperature +20C) > PoE uses 2 wires up, so half the resistance, and 2 wires back, so double > that to get you back where you started. > APPO requires 350mA at 12v > > So working backwards, if you want to lose 1v (ie a 13v psu) at 350ma, you > need 2.86 ohms: thats 19.05 metres (62.49 feet) > > Heres the rest: > Volts Ohms Metres Feet > 13 2.86 19.05 62.49 > 14 5.71 38.10 124.98 > 15 8.57 57.14 187.48 > 16 11.43 76.19 249.97 > 17 14.29 95.24 312.46 > 18 17.14 114.29 374.95 > 19 20.00 133.33 437.45 > 20 22.86 152.38 499.94 > > You can see why they don't bother quoting above 18v. 100+M of CAT5 is > getting a bit long !! > > In reality the APPO etc will have an on board regulator (they would be > unlikely to get it certified without), so there'll be some considerable > tolerance to this. DC resistance of cable and power requirement of radio > will change with temp too. > > bw > > ----- Original Message ----- > From: "Breiland, Derek" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Friday, November 07, 2003 5:07 PM > Subject: RE: [smartBridges] 18v power? > > > > Exactly, hence the need for certification. :) > > > > -----Original Message----- > > From: Hugh Carmichael [mailto:[EMAIL PROTECTED] > > Sent: Friday, November 07, 2003 11:01 AM > > To: [EMAIL PROTECTED] > > Subject: RE: [smartBridges] 18v power? > > > > My cable run is about 250 feet. I ended up using an 18V adapter from my > > notebook PC. The SB site says 15-18V for runs longer than 180 feet. > > > > My question is do you use 15V at 200 feet, 16V at 225 feet, 17V at 250 > > feet etc. It seems like a pretty big gap between 12V to 18V to allow > > for an additional 120 feet (to the max of 300) > > > > > > > > -----Original Message----- > > From: [EMAIL PROTECTED] > > [mailto:[EMAIL PROTECTED] On Behalf Of Breiland, Derek > > Sent: Friday, November 07, 2003 11:50 AM > > To: '[EMAIL PROTECTED]' > > Subject: RE: [smartBridges] 18v power? > > > > It would be really nice if Smartbridges were to actually certify at > > least > > one if not several power supply options. > > > > When we start talking about "be careful of the smoke" we are just > > guessing > > and in this business there is no room for guess work. If we had a > > certified > > product recommended from Smartbridges I think we would all feel better > > about > > using it and in the event we needed support on a problem from > > SmartBridges > > we would know we are using certified equipment to rule that out. > > > > I am awaiting the release of the POE outdoor. Even though I have no > > intentions on using it outdoors it does provide for a higher voltage > > level > > for long cable runs as well as some surge protection the way I > > understand > > it. Not the cheapest solution but just like anything else you get what > > you > > pay for. > > > > Something bothers me about going out to the local Radio Shack for a > > power > > supply to run my AP's etc.. Not to knock Radio Shack but this is a > > situation that needs a commercial grade type solution, not an 18VDC > > power > > supply intended for the general public. > > > > -----Original Message----- > > From: John Hokenson [mailto:[EMAIL PROTECTED] > > Sent: Friday, November 07, 2003 1:29 AM > > To: [EMAIL PROTECTED] > > Subject: Re: [smartBridges] 18v power? > > > > Mouser Electronics.... > > > > JH > > ----- Original Message ----- > > From: "Jeremy Oswalt" <[EMAIL PROTECTED]> > > To: <[EMAIL PROTECTED]> > > Sent: Thursday, November 06, 2003 6:41 PM > > Subject: [smartBridges] 18v power? > > > > > > > Okay, I can't seem to find the articles in the archive concerning > > where to > > > get an 18v DC power supply that works with the Smartbridges. I know > > > Smartbridges is coming out with one, but I can't wait another week. I > > need > > > two for a 170' run. Any recommendations? > > > > > > _____ > > > > > > Jeremy > > > > > > _____ > > > > > > > > > > > > The PART-15.ORG smartBridges Discussion List > > > To Join: mailto:[EMAIL PROTECTED] (in the body type subscribe > > smartBridges <yournickname> > > > To Remove: mailto:[EMAIL PROTECTED] (in the body type unsubscribe > > smartBridges) > > > Archives: http://archives.part-15.org > > > > The PART-15.ORG smartBridges Discussion List > > To Join: mailto:[EMAIL PROTECTED] (in the body type subscribe > > smartBridges <yournickname> > > To Remove: mailto:[EMAIL PROTECTED] (in the body type unsubscribe > > smartBridges) > > Archives: http://archives.part-15.org > > The PART-15.ORG smartBridges Discussion List > > To Join: mailto:[EMAIL PROTECTED] (in the body type subscribe > > smartBridges <yournickname> > > To Remove: mailto:[EMAIL PROTECTED] (in the body type unsubscribe > > smartBridges) > > Archives: http://archives.part-15.org > > The PART-15.ORG smartBridges Discussion List > > To Join: mailto:[EMAIL PROTECTED] (in the body type subscribe > > smartBridges <yournickname> > > To Remove: mailto:[EMAIL PROTECTED] (in the body type unsubscribe > > smartBridges) > > Archives: http://archives.part-15.org > > The PART-15.ORG smartBridges Discussion List > > To Join: mailto:[EMAIL PROTECTED] (in the body type subscribe > smartBridges <yournickname> > > To Remove: mailto:[EMAIL PROTECTED] (in the body type unsubscribe > smartBridges) > > Archives: http://archives.part-15.org > > > > The PART-15.ORG smartBridges Discussion List > To Join: mailto:[EMAIL PROTECTED] (in the body type subscribe smartBridges <yournickname> > To Remove: mailto:[EMAIL PROTECTED] (in the body type unsubscribe smartBridges) > Archives: http://archives.part-15.org The PART-15.ORG smartBridges Discussion List To Join: mailto:[EMAIL PROTECTED] (in the body type subscribe smartBridges <yournickname> To Remove: mailto:[EMAIL PROTECTED] (in the body type unsubscribe smartBridges) Archives: http://archives.part-15.org
