Volt meters are typically very high input impedance, 1 Mohm or more, so that they don't have any effect on the circuit when testing.
On Thu, Oct 18, 2012 at 4:18 PM, Mike Mattox <[email protected]> wrote: > The volt meter is a load, though. > > On 10/18/2012 2:57 PM, Chris Fabien wrote: >> No current = no voltage drop. Ohms Law. >> >> On Thu, Oct 18, 2012 at 3:38 PM, Jeromie Reeves <[email protected]> >> wrote: >>> The resistance of the length of wire. >>> >>> On Thu, Oct 18, 2012 at 11:03 AM, Greg Ihnen <[email protected]> wrote: >>>> A voltage difference with no load? What's causing the drop? >>>> >>>> >>>> On Thu, Oct 18, 2012 at 10:06 AM, Justin Wilson <[email protected]> wrote: >>>>> We see 27.3 volts at the battery. And 27.1 volts at the top with >>>>> no load. >>>>> Obviously load will have an impact on this. >>>>> >>>>> Justin >>>>> >>>>> -----Original Message----- >>>>> From: Jeromie Reeves <[email protected]> >>>>> Reply-To: WISPA General List <[email protected]> >>>>> Date: Thursday, October 18, 2012 9:15 AM >>>>> To: WISPA General List <[email protected]> >>>>> Subject: Re: [WISPA] Another Ubiquity question >>>>> >>>>>> That depends on wire size. That distance is not going to be ethernet >>>>>> so I will assume #12 AWG, 400ft, copper wire, etc. You should be >>>>>> seeing a 5.6% drop under a 1amp load or about 25v under load. >>>>>> >>>>>> >>>>>> On Thu, Oct 18, 2012 at 6:02 AM, Justin Wilson <[email protected]> wrote: >>>>>>> 27 volts at the base. DC has very little loss over 400-500 >>>>>>> foot >>>>>>> distances. We are seeing about .1 volt loss on a 400 foot run. >>>>>>> >>>>>>> -----Original Message----- >>>>>>> From: Scott Lambert <[email protected]> >>>>>>> Reply-To: WISPA General List <[email protected]> >>>>>>> Date: Thursday, October 18, 2012 12:16 AM >>>>>>> To: <[email protected]> >>>>>>> Subject: Re: [WISPA] Another Ubiquity question >>>>>>> >>>>>>>> On Wed, Oct 17, 2012 at 10:14:03PM -0400, Justin Wilson wrote: >>>>>>>>> Many UBNT deployments running at 27volts of clean DC power. Not >>>>>>>>> saying it's ideal but it works. >>>>>>>> 27v at the ethernet port or 27v at the base of the tower? >>>>>>>> >>>>>>>> -- >>>>>>>> Scott Lambert KC5MLE Unix >>>>>>>> SysAdmin >>>>>>>> [email protected] >>>>>>>> _______________________________________________ >>>>>>>> Wireless mailing list >>>>>>>> [email protected] >>>>>>>> http://lists.wispa.org/mailman/listinfo/wireless >>>>>>>> >>>>>>> >>>>>>> _______________________________________________ >>>>>>> Wireless mailing list >>>>>>> [email protected] >>>>>>> http://lists.wispa.org/mailman/listinfo/wireless >>>>>> _______________________________________________ >>>>>> Wireless mailing list >>>>>> [email protected] >>>>>> http://lists.wispa.org/mailman/listinfo/wireless >>>>>> >>>>> >>>>> _______________________________________________ >>>>> Wireless mailing list >>>>> [email protected] >>>>> http://lists.wispa.org/mailman/listinfo/wireless >>>> >>>> >>>> _______________________________________________ >>>> Wireless mailing list >>>> [email protected] >>>> http://lists.wispa.org/mailman/listinfo/wireless >>>> >>> _______________________________________________ >>> Wireless mailing list >>> [email protected] >>> http://lists.wispa.org/mailman/listinfo/wireless >> _______________________________________________ >> Wireless mailing list >> [email protected] >> http://lists.wispa.org/mailman/listinfo/wireless >> > > _______________________________________________ > Wireless mailing list > [email protected] > http://lists.wispa.org/mailman/listinfo/wireless _______________________________________________ Wireless mailing list [email protected] http://lists.wispa.org/mailman/listinfo/wireless
