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The Telecom Digest for Dec 3, 2014
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|Date: Tue, 02 Dec 2014 07:03:31 -0500 From: "Elmo P. Shagnasty" <email@example.com> To: firstname.lastname@example.org. Subject: Re: Majic Jack Go Power Issue Message-ID: <elmop-86AA71.email@example.com> In article <firstname.lastname@example.org>, "Fred Atkinson" <email@example.com> wrote: > After they asked me questions about how I had hooked it up, > they told me to unplug it from the UPS and plug it directly into a > wall outlet. I did so and it began to work. When I asked them what > we needed to do to make it work on the UPS (so I don't lose > communications when the power goes off), they told me it could not > be made to work on a UPS. Actually, what they were saying--and should have said explicitly--is that if it works in a regular outlet but not your UPS, you must examine your UPS--and they don't support your UPS. They can't. > So if I lose power, I lose communications because of a design > flaw in their power supply. How do you know it isn't a flaw in your UPS? Have you tried a different UPS? > If they could find a way to fix this (a third party power supply, > for example), I would be OK with that. If the flaw is in your UPS--and so far evidence strongly points to that--what do you expect them to do? They can't fix your UPS. Of course, power is power. As long as you meet the specs, you can use any power supply. ***** Moderator's Note ***** Four rechargeable AA cells in series would be about 5 volts: you could probably power the Magic Jack from those, and "float" the input power across them. Bill Horne Moderator|
|Date: Tue, 02 Dec 2014 01:33:58 -0600 From: GlowingBlueMist <GlowingBlueMist@blackhole.io> To: firstname.lastname@example.org. Subject: Re: Majic Jack Go Power Issue Message-ID: <HXdfw.email@example.com> On 11/30/2014 8:44 PM, Fred Atkinson wrote: > I recently switched my home phone service to Majic Jack. I > ordered their newest device called a Magic Jack Go. > > With my previous arrangement, I have a separate UPS to power my > cable modem, my Cisco 871 router, and my VOIP device. This is so I > don't lose phone service in the event of a power outage. > > When my Magic Jack Go arrived, I activated it and plugged it into > my UPS with my other devices. I connected it to my Cisco Router with > an Ethernet cable and I connected it to my phone. > > I could not make it work. [Moderator snip] > > ***** Moderator's Note ***** > > Please tell us what the input voltage is, and if it's "AC" or "DC". > > Bill Horne > Moderator The MagicJack Go uses just your standard 5-volt DC from a USB port or a standard 120 to 5-volt DC USB charger. What it sounds like is that the UPS being used is sending out a modified sine wave or square wave output when it is running and the small UPS power adapter supplied by MagicJack Go is designed to only work with a true sign wave 120v input. What I would do is try a couple of other USB charger adapter power supplies and see if one of them will work with your UPS and the MagicJack Go. I have read that others are using the same hardware supplied with the MagicJack Go with a UPS but I suspect theirs is supplying the real sign wave output on the 120 volt side like from an actual wall outlet. What brand/model is your UPS?|
|Date: 2 Dec 2014 03:56:12 -0000 From: "John Levine" <firstname.lastname@example.org> To: email@example.com. Subject: Re: Majic Jack Go Power Issue Message-ID: <firstname.lastname@example.org> > The power supply plugs into a standard AC receptacle (110VAC). The >Magic Jack Go plugs into the power supply via a USB port. That's quite peculiar. If it uses a normal mini- or micro-USB connector, you might try plugging it into a cell phone charger, which is supposed to provide the same voltage on the same connector, and see what happens. Also, are you sure your cable service will continue to work when the power goes out? Battery backup and UPS on outside cable plant tends to be spotty. R's, John|
|Date: Tue, 2 Dec 2014 11:11:35 -0800 (PST) From: HAncock4 <email@example.com> To: firstname.lastname@example.org. Subject: Utilities: major power failure hits Detroit Message-ID: <email@example.com> CBS News reported that a major power outage affected multiple buildings in downtown Detroit on Tuesday. The downtown electrical grid failed at around 10:30 a.m. Tuesday, impacting 100 Detroit Public Lighting Department customers, reports CBS Detroit. "The city's public lighting grid suffered a major cable failure that has caused the entire grid to lose power," the city said in a statement. "The outage is affecting all customers on the PLD grid. We have isolated the issue and are working to restore power as soon as possible." for full article and links to related stories, please see: http://www.cbsnews.com/news/downtown-detroit-hit-with-major-power-outage/ ***** Moderator's Note ***** I was tempted to reject this, but I realized that nothing is more essential to telecommunications than power. Bill Horne Moderator|
|Date: Tue, 02 Dec 2014 12:01:54 -0600 From: Doug McIntyre <firstname.lastname@example.org> To: email@example.com. Subject: Re: Majic Jack Go Power Issue Message-ID: <55ednUMuKsIPY-DJnZ2dnUU7-fmdnZ2d@giganews.com> Frank Stearns <firstname.lastname@example.org> writes: >"Fred Atkinson" <email@example.com> writes: >> After they asked me questions about how I had hooked it up, they >>told me to unplug it from the UPS and plug it directly into a wall >>outlet. I did so and it began to work. ... >Did they specify the limitation? This makes absolutely no technical >sense to me with either a standby UPS (which simply passes through >the incoming line voltage until that goes away and there is then a >quick change over to UPS power) or an "always on" double-conversion UPS. The waveform output of a generic "consumer" grade UPS is pretty poor. There have been many efforts in the sales literature, especially around APC, that they have the best output waveform, and APC especially makes a point of saying theirs is the best sinesoidal. Here's one case-study/comparison of UPS power vs. wall power. https://www.ipqdf.com/case-studies/monitoring/general-ups-switching-waveforms/ That, combined with just how horrendously designed almost every USB wall-wart power device is, I could easily see there being problems. Apple's design is one of the best. Knock-off of Apple's devices typically being some of the worst. Various other vendors in the middle. Why do you think there are stories about people being electrocuted by their phones while plugged in and charging? Piss-poor USB power wall warts. Since the OP states that the device is USB powered, what I would do if I were him would be to get a powered USB hub instead, shouldn't matter what size or capabilities, as long as it is powered, ie. has a power supply to plugin, and then probably plug the USB cable into it. The power design for powered USB hubs are quite a bit better, since it typically has to provide a bunch more power than just barely enough to do the one device thing. That should work better off the UPS. (Another area of power that is related is in the case of inverters (ie. in RVing when you need to power devices off 12V lead-acid cells) especially consumer grade ones, the output of inverters is also pretty poor overall, and there are numerous reports of problems all around with powering devices off bad inverters, especially electronic type devices. -- Doug McIntyre firstname.lastname@example.org|
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