Seems like I missed a big chunk of the middle of this thread somehow. A few points, not necessarily relevant to the immediately below comment:
1) There are lots of 48VDC to 24VDC PoE adapters already on the market. Not the least of which is the UBNT INS-3AF-I-AG, which is 48V/802.3af in 24VDC out. At $22.95 it is cheap enough that I'd personally have to have to think twice about designing a product which did exactly this, unless it was in a different, more wisp-friendly form factor. In addition to the above, there are several single PoE injectors on the market which take a hardwired 48V in, and spit 24V out. Or vice versa. 2) Yes, power supplies seem to be more expensive at 48VDC. I'm 100% sure that this is because there are significantly fewer options for power supply controller IC's at >30V or so. Plus capacitors get a lot more expensive, etc.. 3) In another thread I mentioned that the new control boards on the rackinjector would accept either voltage (+ or - 48VDC). The existing injection boards just pass through voltage so +-48VDC in, +-48VDC out. However, the underlying technology I'm using to make the control board happy with -48VDC can (according to the datasheet) also handle 24V or 48V out at up to about 12W. I'm in the processes of verifying that this will work to power a typical 802.11 based radio. I'm about 85% certain this will turn into initially a board for the rackinjector which can take any voltage between -60V and +60V (except -10 to +10) and put out 24V or 48V on a given port, at up to 12W per port. Other variations would come shortly thereafter. Assuming a successful implementation, it is still up in the air about how you will select your output voltage - it might be buy a board for your voltage, or it might be modular and/or jumpers. Cost will pay a big part of this decision. On Mon, Jun 25, 2018 at 8:04 AM, Adam Moffett <dmmoff...@gmail.com> wrote: > What about a magical correct power adapter? Anything in / anything out, > and it knows what to do automatically. > Needs a bottle opener on it too. > -Adam > > > ------ Original Message ------ > From: "Chuck McCown" <ch...@wbmfg.com> > To: "AFMUG" <af@af.afmug.com> > Sent: 6/24/2018 9:41:10 PM > Subject: Re: [AFMUG] ePMP voltages again - specifically 2ghz > > Not a problem, not cheap. >> >> What kind of form factor? >> >> What kind of in and out voltages? Certainly doable. >> I think Forrest has something similar in his latest stuff. >> >> Would you want it to pull it off of the Ethernet cable and then put it >> back on the Ethernet cable at a different voltage? >> >> >> -----Original Message----- From: Robert Andrews >> Sent: Sunday, June 24, 2018 4:50 PM >> To: AFMUG >> Subject: Re: [AFMUG] ePMP voltages again - specifically 2ghz >> >> oh. or any 48 and makes it +48.... i.e pass through if already ok... >> >> On 06/24/2018 02:45 PM, Gino A. Villarini wrote: >> >>> How about a dc-dc poe/SS that takes –48 and converts to +48, 24v etc ? >>> >>> From: AF <af-boun...@af.afmug.com <mailto:af-boun...@af.afmug.com>> on >>> behalf of Chuck McCown <ch...@wbmfg.com <mailto:ch...@wbmfg.com>> >>> Date: Thursday, June 21, 2018 at 12:53 PM >>> To: Mathew Howard <mhoward...@gmail.com <mailto:mhoward...@gmail.com>>, >>> David Milholen <dmilho...@wletc.com <mailto:dmilho...@wletc.com>> >>> Cc: AFMUG <af@af.afmug.com <mailto:af@af.afmug.com>> >>> Subject: Re: [AFMUG] ePMP voltages again - specifically 2ghz >>> >>> *//* >>> >>> */Gino A. Villarini/* >>> >>> President >>> Metro Office Park #18 Suite 304 Guaynabo, Puerto Rico 00968 >>> >>> Me too... >>> So, what appetite is there for an inline POE regulator that would >>> convert 48 to 24? >>> *From:* Mathew Howard >>> *Sent:* Thursday, June 21, 2018 10:50 AM >>> *To:* Dave >>> *Cc:* AFMUG >>> *Subject:* Re: [AFMUG] ePMP voltages again - specifically 2ghz >>> ugh... I keep forgetting to use reply-to-all... >>> Not every single UBNT radio... all the airfibers will happily take 48v. >>> Mikrotik is finally starting to make most of the new stuff handle 48v >>> (including the PowerBox Pro), but yeah. UBNT is the reason I still have to >>> use 24v on most of our towers... they make a converter you can stick on in >>> line with the radios, but that's kind of a pain if you have more than one >>> or two, and it's an extra part to fail. >>> On Thu, Jun 21, 2018 at 11:46 AM, Dave <dmilho...@wletc.com> wrote: >>> >>> They make dental floss for that :) >>> >>> >>> On 06/21/2018 11:39 AM, Josh Luthman wrote: >>> >>>> Except for every single Ubnt device and a majority of Mikrotiks.... >>>> Josh Luthman >>>> Office: 937-552-2340 >>>> Direct: 937-552-2343 >>>> 1100 Wayne St >>>> Suite 1337 >>>> Troy, OH 45373 >>>> On Thu, Jun 21, 2018 at 12:39 PM, Josh Baird <joshba...@gmail.com> >>>> wrote: >>>> >>>> I promise life will be easier if you just use 48V. :) >>>> On Thu, Jun 21, 2018 at 12:35 PM, Josh Luthman >>>> <j...@imaginenetworksllc.com> wrote: >>>> >>>> I'm trying to use a Powerbox Pro to power up two epmp >>>> APs. The 5 GHz is just fine but the 2 GHz is saying >>>> current too low. Both ports are getting 23 volts and the >>>> cables are <10 feet (from the Powerbox Pro). >>>> Does anyone know if the 2ghz requires more voltage possibly? >>>> Spec sheet does say 23 volts min but it's weird one powers >>>> (5 ghz) and the other doesn't. >>>> Josh Luthman >>>> Office: 937-552-2340 >>>> Direct: 937-552-2343 >>>> 1100 Wayne St >>>> >>>> <https://maps.google.com/?q=1100+Wayne+St+Suite+1337+Troy,+ >>>> OH+45373&entry=gmail&source=g> >>>> Suite 1337 >>>> >>>> <https://maps.google.com/?q=1100+Wayne+St+Suite+1337+Troy,+ >>>> OH+45373&entry=gmail&source=g> >>>> Troy, OH 45373 >>>> >>>> <https://maps.google.com/?q=1100+Wayne+St+Suite+1337+Troy,+ >>>> OH+45373&entry=gmail&source=g> >>>> -- AF mailing list >>>> AF@af.afmug.com >>>> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >>>> <http://af.afmug.com/mailman/listinfo/af_af.afmug.com> >>>> >>>> >>>> >>>> >>> -- >>> -- AF mailing list >>> AF@af.afmug.com >>> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >>> <http://af.afmug.com/mailman/listinfo/af_af.afmug.com> >>> >>> ------------------------------------------------------------------------ >>> -- AF mailing list >>> AF@af.afmug.com <mailto:AF@af.afmug.com> >>> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >>> >>> >>> >> -- AF mailing list >> AF@af.afmug.com >> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >> >> -- AF mailing list >> AF@af.afmug.com >> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >> > > > -- > AF mailing list > AF@af.afmug.com > http://af.afmug.com/mailman/listinfo/af_af.afmug.com > -- *Forrest Christian* *CEO**, PacketFlux Technologies, Inc.* Tel: 406-449-3345 | Address: 3577 Countryside Road, Helena, MT 59602 forre...@imach.com | http://www.packetflux.com <http://www.linkedin.com/in/fwchristian> <http://facebook.com/packetflux> <http://twitter.com/@packetflux>
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