Do powerline adapters work during a power cut?

My electricity is being switched off next Thursday for 8 hours. I can't
think of any reason why my powerline adapters shouldn't continue to
work, but will they? I've got some battery-powered Raspberry Pis in a
part of the house where the WiFi doesn't work.
Another Dave
Reply to
Another Dave
The devices need mains to power them so they will act as comms devices - ie to convert between Ethernet and the modulation that is applied to the mains voltage on the house wiring, and the convert back to Ethernet in the other device.
I wonder if they would extract power from the Ethernet if both powerlink devices were plugged into computers that provided PoE (power over Ethernet).
I think you may be out of luck.
I presume you've got a way of powering your router by battery, to access the internet, and to hand out IP addresses to new devices (via DHCP).
Thinking *really* laterally - and I'm not for a minute suggesting that you try this - in theory you could connect one powerlink device and your router to a 12V-to-mains converter (powered from a car battery) and then run an extension cable to another place where a powerlink device is plugged in. But I'd bet the 12V-to-main converter will output such a horrible approximation of a sine wave that the noise it generates would swamp the powerlink signal. DON'T TRY IT - it's only a thought experiment.
I did once earn a few brownie points when the small business where I was working suffered a power cut (JCB through high voltage cable somewhere in the area) and the company couldn't even make/receive phone calls because their phone system was entirely by VOIP. They couldn't even look up their list of customers and their work diary to see which customers they were booked for us (PC repair engineers) to visit, or the customers' phone numbers to explain why we may be late. Luckily I had a 12V-to-mains converter in my car (I bought it so I could charge my laptop while I was driving etc), so they were able to rig it up to the company van (engine ticking over so battery didn't go flat) and power a VOIP-to-POTS interface so all incoming phone calls came through to a backup hard-wired phone, and they managed to boot up their diary server and a router, and access it from a laptop. It kept them going until the mains came back. I didn't see how well they coped because I had to go out to see one of the customers whose details we could remember because we had a paper copy of the job sheet, and by the time I got back, normal service had been resumed. The buggers still made me redundant a few months later :-(
Reply to
NY
Think about where the electronics in the adaptor are powered from, and you will have your answer! :-)
Reply to
John Rumm
When a local village had it's planned electricity shut down for the day I installed the wiring for a 3 phase genny for the local pub.
As I had swapped the power from mains to the genny before 8am someone asked how will we know when the power is turned off.
My answer was just wait for the all the alarm bell boxes to go off that have dead batteries in the control panel.
Reply to
ARW
If you think about it, they already need an enormous notch filter at 50Hz, and they need to compensate for all kinds of electrical noise that's on the mains from whatever electrical gear happens to be connected (SMPSUs especially). They're already adaptive enough to scan for good frequencies they can use to transmit, and I suspect the harmonics from the sine wave converter are relatively predictable. The bit rate may be well down, but I would expect them to still work.
Theo
Reply to
Theo
Don't be stupid, how do you think they get their power? If you have a back up generator that can feed the house sockets, then maybe, but I'd not expect great reliability myself. Brian
Reply to
Brian Gaff (Sofa)
Also how will the wifi work and indeed the router if you are connected to the internet that way. You could set up a mobile as a hot spot and do it over mobile data, but then you would need to reset all your passwords and oog in stuff as well. If the weather is good go to the coast instead! Brian
Reply to
Brian Gaff (Sofa)
AS everyone knows powerline adaptors cause no end of problems over the short wave bands. Sure they have notches for the ham radio bands, but not for the international short wave bands, producing a ticking and screeching noise from about 3Mhz all the way up to 28Mhz. Most seem to be wired not to use the mains to carry the signal at all, but use some form of brute force method to put out a broad band modulate carrier and I remember one could actually use them wirelessly over short distances due to the radiation from the house wiring. The thing is house mains wiring is nothing like an RF feeder and as such leaks the signal over wide areas. How on earth these were allowed to be used anywhere in the world I have no idea. I know that some Aircraft communications stations in places like Irish Republic (Shanwick) and the Azores have found these devices being used locally to be a problem as they use frequencies in the short wave bands to talk to long haul aircraft. not all are using space based communication, and are too far out for vhf. Bah Humbug.
Brian
Reply to
Brian Gaff (Sofa)
If one is determined to continue to produce wideband RF interference over several miles one could do this. But the simpler solution would run a bit of Cat5e instead of the mains extension cable and get a much better data connection without the inverter and powerline adaptors.
Reply to
Roger Hayter
I agree that Cat 5 is always the best solution: the one that will "just work" without any intermittent loss of connection, failure to reconnect after power cut (*), sudden drop in speed when a microwave is turned on, or bizarre interactions between wifi and bluetooth (**).
But it almost always involves trying to route the cable between one room and another, buried under the edge of the carpet, fed under the metal carpet strips in doorways, or else drilling through walls or ceilings to feed the cable and plug through. I did initially think of laying Cat 5 in the loft, to feed a wifi access point for the part of the house where wireless devices would be used, but it would have meant drilling through the ceiling into the loft, crawling along in very confined spaces near the eaves, and finding a way of hiding a cable going vertically from floor to ceiling. I quickly dismissed powerline because the house has two separate "fuse boxes" (although on the same meter) and the signal strength gets very much worse when you cross from one ring main to the other; it was pretty dire even a few sockets away on the same ring main. Simple wifi (even 2.4 GHz) from the router was woefully inadequate, so we had to invest in several mesh devices - which work beautifully most of the time, until the problem when the power goes off and the devices don't reconnect once it comes back.
(*
) We have a mesh network to get broadband from one part of the house to cover a "wing" at right angles. Getting the devices to connect after a power cut (as happened in the middle of last night) is a problem, because if the power to all the nodes is restored simultaneously, the child nodes don't connect to the parent; instead the children need to be turned off and then back on in sequence after the central parent node has started.
(**) On my old phone, I couldn't listed to streamed radio programmes (eg via BBC Sounds and its previous iPlayer equivalent) via bluetooth headphones because the phone didn't like bluetooth and 2.4 GHz wifi transferring data at the same time. The solution was to use wired earphones when streaming over wifi, or else transfer the file so it was held locally on the phone and then listen using bluetooth headphones.
Reply to
NY
Sounds like a small UPS holding up the parent and main router etc might solve that for the majority of power outages.
Reply to
John Rumm
Presumably, it's a standard feature in all new builds ? He asked, damn well knowing that would be far too easier a thing to arrange for the English "way of doing things".
Reply to
Jethro_uk
If you don't have cat 5, but have decent aerial cable (ie CT100, not the horrible brown stuff) you can use MoCA to run ethernet over coax. I have some bonded MoCA adapters that got approaching gigabit over the TV coax. You simply put a MoCA adapter between the TV access point on the wall and the TV and tap off ethernet.
I never got around to measuring them in a controlled test, but internet connection was 200Mbps and it handled that without breaking sweat, over a fairly sprawling house.
In theory you're supposed to have a MoCA-capable splitter (one that handles satellite frequencies is fine) and a blocking filter to prevent the signal leaking upstream, but all the points came off an existing aerial booster and I just ran the MoCA across ports of the booster without touching that setup at all.
I used it to run a WAP and office at the other end of the house from the FTTH incomer, and it worked very well.
Theo (I have the parts for sale if anyone wants them)
Reply to
Theo
On 22 May 2020 at 10:33:09 BST, John Rumm wrote:
Yes, just what we have for the frequent, few-second, outages that we get.
Reply to
Tim Streater

Site Timeline Threads

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.