Noise on the line

[R791945]

I have a power line adapter (PLA) which is not passing through the Ip connection at the speed it is arriving at the BT Hub. It comes in at 55mbps and a speed test on the computer shows it is running at 28mpbs.

I have discovered that a number of essential items such as a burglar alarm are plugged into the mains circuit. Through isolation I have found that they are causing the power line adapter to run slowly.

I spoke to the manufacturer of the PLA and they recommend that I put in line conditioners at each socket to prevent the noise passing through to the mains circuit. Rather than buy lots of their adapters I wonder if it is possible to put my own suppressor into the plug, socket or round the socket lead.

I am in the UK so the power is 240v.

If go to my local electronic parts shop and ask for a suppressor what spec should I look for?

Having done a search I am not clear what type of suppressor is required because the manufacturer also said that if I have surge suppressors on the circuit that could cause a slow down because of the added noise they give to the mains circuit even though they iron out the supply to the computer.

 

[AnalogKid]

When most people hear suppressor they think transient suppressor, like MOV's or Tranzorbs. Make sure your supplier knows you want what is called in the States a power line filter. Depending on the internal construction, some filter better in one direction, and are clearly marked with input and output sides. Usually the input is from the power line and the output is to the equipment. However, there is nothing wrong or unsafe about installing one "backwards" for better performance keeping equipment noise off the power line.

ak

 

[R791945]

When most people hear suppressor they think transient suppressor, like MOV's or Tranzorbs. Make sure your supplier knows you want what is called in the States a power line filter. Depending on the internal construction, some filter better in one direction, and are clearly marked with input and output sides. Usually the input is from the power line and the output is to the equipment. However, there is nothing wrong or unsafe about installing one "backwards" for better performance keeping equipment noise off the power line.

ak

Thank you for your reply. As I am dealing with AC does it mean that a filter has to go to both the pos and neg supplies to the equipment? I assume the way to set this up is to cut into the cable put in a box with the two filters in it.

I have seen some equipment come with magnets that fit over the cable. Is that for some other reason that power line noise?

 

[shrtrnd]

I think we're unclear as to whether your power line filter is to be used at a standard power socket, or if you intend
to integrate it into your many PLA 'sockets'.
We basically don't know exactly what it is you intend to do, so it's hard to give good suggestions.

Those aren't magnets on the cables, they're ferrite assemblies, to suppress noise on the line.

 

[R791945]

My previous comment was thinking aloud on the possibilities. I was unclear which way to go. I could see more than one way to setup the suppressor. I would prefer the PLA to be used inside the power socket but I have not found a sample on an UK site. Do you know what these suppressors are known as in the UK?

 

[AnalogKid]

There is no pos and neg in AC. Please be more clear about the equipment and what you want to achieve. A sketch would help.

ak

 

[R791945]

There is no pos and neg in AC. Please be more clear about the equipment and what you want to achieve. A sketch would help.

ak

Thank you for your helpful response. In case it is still unclear I was asking if two suppressors are needed for each socket or just the one.

I want to achieve a reduction in the noise on the mains line within my flat. It is causing the internet speed to drop dramatically. It arises from noise on the line from various devices, and was asking for help as to what components are available to suppress it. It is too early to give a sketch as I am not at that stage.

 

[AnalogKid]

Powerline filters use a two-winding common mode choke that is the inductor for both common mode and differential mode L-C filters. As such, one physical filter attaches to and passes through both sides of an AC powerline. If by socket you mean a standard AC wall outlet, then one filter per socket.

ak

 

[R791945]

Powerline filters use a two-winding common mode choke that is the inductor for both common mode and differential mode L-C filters. As such, one physical filter attaches to and passes through both sides of an AC powerline. If by socket you mean a standard AC wall outlet, then one filter per socket.

ak

Thank you again for your help. I searched in CPC.farnell.com for "two-winding common mode choke" and they presented a number of Common mode chokes at (http://bit.ly/2i8wo0O) . They vary in price according to rating in Amps and hertz eg [85UH, 12A] or [10MH, 2A] or [32UH, 8.5A]. Is that what you are referring to? It looks like each choke has two connections and what I gather from your last comment is that each connection goes into a different power connector on the back of the AC wall outlet (if DC it would be neg and pos).

If I have found the right type of powerline filter I enquire how I decide which one to buy? Is it purely on Amps because I assume that frequency also comes into the choice because I notice that the 8.5A choke is more expensive than the 12A choke and difference is the Hertz rating.

 

[AnalogKid]

There is more to a power line filter than just the choke. Look at power line filters from Corcom, Schurter, Delta to see what a commercial device looks like. You start with the current, then look at various models with different filter characteristics. The better the filtering, the larger the part.

ak