The reasoning behind not just throwing in a single 18V for all applications is because in shorter cable runs, there will not be much of a voltage drop over the Cat5, causing an excess amount of voltage to reach the unit, possibly damaging it. I do believe a switch would work though on the powershot, which could vary the amount of resistance inside the powershot depending on how long your cable length was. Ryan
> I agree with Jack. > > At most, why note make a power shot with three settings: 12v, 15v, and > 18v? That would seem simpler and cheaper than trying to build > potentially troublesome intelligence into it. > > Sam > Not an EE > > :) > > On Thu, 12 Jun 2003, Jack Berridge > wrote: > >> Sounds interesting....and scary. I'm not an EE but when you start >> talking about an "intelligent powershot" that is capable of making >> decision based on "sensing the cabling length" it scares me. This >> scares me because "intelligent devices" tend to die (fail) more often >> than a good old dumb device that's only purpose is to provide a >> specific (designed/engineered) amount of power. To me, I see an >> intelligent device as another point of failure just waiting to >> happen. Whereas, if we had a straight 18v power supply (powershot) >> it's either working.....or not. No intelligence, no extra features >> or sensors to worry about failing --- just good old power source that >> is capable of supplying 18v as designed/engineered. Why do you feel >> the need to have an intelligent powershot versus one single straight >> 18v that works for short and/or long Ethernet cable runs? >> >> Thanks. >> >> >> >> Jack >> >> >> >> At 12:10 AM 6/12/2003 +0800, you wrote: >> >This is going to change. As I mentioned earlier, we are working to >> >have higher power voltage adaptor and with intelligent powershot >> >that can dynamically adjust the power supply based on cable length >> >sensed. So it will be one universal AC power adaptor. >> > >> >Alex >> >sB Tech Support >> > >> > >> >-----Original Message----- >> >From: [EMAIL PROTECTED] >> >[mailto:[EMAIL PROTECTED] On Behalf Of Jack Berridge >> >Sent: Wednesday, June 11, 2003 9:37 PM >> >To: '[EMAIL PROTECTED]' >> >Subject: RE: [smartBridges] POE, voltage range >> > >> >Curious. If you highly recommend using smartBridges power supply for >> > smartBridges devices, why doesn't smartBridges have a power supply >> >and PoE solution that works to the maximum Ethernet cable specs >> >(~300 feet)? Why even have the 12v power supply? Why not have an >> >18v power supply that will work with the 50' or less cable runs as >> >well as the longer cable runs? At least for the outdoor (WISP type) >> >solutions. Other vendors we work with use the higher end (18v, even >> >24v) power supplies and it works for the short as well as the long >> >runs. It just seems that the 12v has caused your user community >> >more problems which are resolved by going to 15v or 18v >> >solutions......why not have an 18v be the normal (default) solution >> >for outdoor smartBridges solutions? >> >Thanks. >> > >> > >> > >> >Jack >> > >> > >> > >> > >> > >> > PM 6/11/2003 +0800, you wrote: >> > >> >>If you are using any third party power supply, please use the >> >>regulated DC voltage power supply. We are highly recommended to >> >>use our smartBridges Power supply for our devices. >> >>If the Ethernet cable length exceeds more than 50 meters, then only >> >>18V is recommended. >> >> >> >>Seeni, SB support >> >> >> >> >> >>-----Original Message----- >> >>From: [EMAIL PROTECTED] >> >>[mailto:[EMAIL PROTECTED] On Behalf Of phantam >> >>Sent: Wednesday, June 11, 2003 9:57 AM >> >>To: '[EMAIL PROTECTED]' >> >>Subject: RE: [smartBridges] POE, voltage range >> >> >> >>Dynamic power sounds intriguing. >> >> >> >>---------- >> >>From: Mark Koskenmaki [mailto:[EMAIL PROTECTED] >> >>Sent: Tuesday, June 10, 2003 7:32 PM >> >>To: [EMAIL PROTECTED] >> >> >> >>Thank you. I have no fears of even reaching 15V, but wanted to >> >>make sure that even if somehow things got to 15.5 or 16, it would >> >>be ok. >> >> >> >>Thanks again. >> >> >> >>Mark >> >> >> >> >> >>NEOFAST.NET >> >>North >> >>East >> >>Oregon >> >>FAST >> >>Net >> >>mark(at)neofast.net >> >>----- Original Message ----- >> >>From: <mailto:[EMAIL PROTECTED]>Alex Wong >> >>To: <mailto:[EMAIL PROTECTED]>[EMAIL PROTECTED] >> >>Sent: Tuesday, June 10, 2003 11:29 AM >> >>Subject: RE: [smartBridges] POE, voltage range >> >>We recommend 18V as max athough can be higher. Pls refer to this >> >>link for more details. >> >><http://www.smartbridges.com/new/products/ps.php>http://www.smartbridges.com/new/products/ps.php>> >> >> >> >> >> >> >>We are also in the development stage of having a dyanmic power >> >>supply that can automatically adjsut the power supply based on the >> >>cable sense. Alex >> >>sB Tech Support >> >>-----Original Message----- >> >>From: [EMAIL PROTECTED] >> >>[mailto:[EMAIL PROTECTED] On Behalf Of Mark Koskenmaki >> >>Sent: Wednesday, June 11, 2003 12:03 AM >> >>To: '[EMAIL PROTECTED]' >> >>Subject: [smartBridges] POE, voltage range >> >>What's the upper limit for voltage, for POE on the ABO and APPO? >> >>Thanks >> >>NEOFAST.NET >> >>North >> >>East >> >>Oregon >> >>FAST >> >>Net >> >>mark(at)neofast.net >> >>--- >> >>Outgoing mail is certified Virus Free. >> >>Checked by AVG anti-virus system >> >>(<http://www.grisoft.com>http://www.grisoft.com). >> >>Version: 6.0.488 / Virus Database: 287 - Release Date: 6/5/03 >> > > 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://198.63.203.6 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://198.63.203.6
