transmitting signal across power line

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Hello all, is it possible and how to realize communication between computer and avr in the next scheme?
Is there any tutorial or other documentation that talks about this?

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There are commercial units around for doing this and a lot of developent funds have been used getting there
http://www.maxim-ic.com/powerlin...
is a good starting point
Try Google
communications over power lines

Keep it simple it will not bite as hard

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There are also ready build modules available for about $18-$30

check here: http://www.archnetco.com/english...

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blueled wrote:
There are also ready build modules available for about $18-$30

check here: http://www.archnetco.com/english...


Do they work at 10KV, or did I misunderstand the OP?

Four legs good, two legs bad, three legs stable.

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The generating and distribution companies have been working on it.
http://standards.ieee.org/announ...
http://www.cogency.com/B_Support...
In fact there are a lot of hits with Google
OP take the hint please.

Keep it simple it will not bite as hard

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@sutton
I find some useful articles with Google.

I need to measure active power, voltage and current in one part of city (this is not the problem), then those informations I must send to my host computer in another part of City (this is the problem, how to send it :D).

Between this meter (the meter with avr who measure active power, voltage and current) and my host computer I have two transformers, like on my above picture.

AVR (the meter) is connected to 220V and I need to inject my signal to power line 220V, 50Hz and receive that signal in the host computer via RS232. But I don't know will I lose my signal between these two transformers.

('my signal' is the signal with informations about active power, voltage and curent)
I hope you understand my problem.

BTW what's mean "OP"?

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Of course, a link going around that power line might be easier.

---
Formerly Torby. Stitch626 just seemed a more descriptive nicname.

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slavko wrote:
BTW what's mean "OP"?

"OP" is an abberviation for "original poster", or "the person who started this thread".

In this context, it was used to help distinguish information that was being directed to everyone who was participating in the conversation, from a comment that was being directed at one specific user.

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Transmitting data over power line in one building, residence, etc, can be done.

It is MUCH harder when you have to go through transformers, etc. One, fairly old system is called "carrier current" but was primarily used as a substitute for AM broadcast. A newer system is BPL (Broadband over Power Line). It is the source of a lot of controversy in the US and has required Federal Communications Commission approval. But, even they have to provide highfrequency "shunts" around the transformers and that requires the cooperation of the power utility. Unless this involves monitoring FOR the power utility, the probems would be nearly insurmountable. And, if it DOES involve the power utility, the would still be a huge amount of research ahead of you.

Jim

Jim Wagner Oregon Research Electronics, Consulting Div. Tangent, OR, USA http://www.orelectronics.net

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@Ifmorison
thanks

@ka7ehk
The problem is more difficult than I thought, I will try some another solutions for remote metering.

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Hi

How far apart are you talking about for your distance ?

Just a thought, why not use a mobile phone or use a landline phone with a modem at one end & something simular at the other. Here you can ring your distant phone & transfer your data to your PC.

Regards
Ken

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The distance between the meter and the host pc is about 8-10 kilometre, I don't know exactly how far.

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Wow, that's far.
What about net access ? Then you can just use the internet.

/Jesper
http://www.yampp.com
The quick black AVR jumped over the lazy PIC.
What boots up, must come down.

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You can get a GSM module with GPRS and TCP/IP stack for ~ $70 and then use the internet as Jesper suggested.

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Sorry to divert the topic but i am just curious to know whether this system works if the two units are connected to different phases of power grid i.e. Is it possible for the device connected on R phase to communicate with the device connected to phases B and Y as well?

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Quote:
The distance between the meter and the host pc is about 8-10 kilometre, I don't know exactly how far.

If the power cable goes through any transformer, which it probably will over that distance, I dont think you will ever be able to communicate over this distance.

 

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There was a guy ta Manchester doing a Phd who was involved with wind power and comms using the power lines.I believe he got a system working but it was slow, he found it wierd that when he went to conventions a lot of guys who had not done it said it could be done using high bit rates.

Keep it simple it will not bite as hard

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Power lines communications (PLC) is complex engineering task. Many companies have applying diverse technologies to 'reliably' achieve these comm links, using ultra low frequencies, spread spectrum, multi frequency, transmit a zero crossing, etc etc.. The underlying problem is that power lines are vey complex, variable, affected by many factors and loads connected to them.

Bridging over transformers is quite hard, unless you work with very low frequencies, and in polyphase systems you need to provide for phase to phase bridges in case your transceivers are not sharing the same phase. You may run into regulatory issues depending on the bands you want to use too.

You can get some info on companies doing AMR (automatic meter reading) like Hunt technologies, DCSI, and meter manufacturers like Ampy.

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@rberger

Quote:

If the power cable goes through any transformer, which it probably will over that distance, I dont think you will ever be able to communicate over this distance.

yes, the power cable goes through transformers and this is the problem, we have about 10 houses connected to one transformer. A data communication over a mobile phone is interesting, but one mobile phone per house is very expensive.

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Could you have a small hub at each transformer into a GSM module so information is collected from each block of houses then passed on?

Keep it simple it will not bite as hard

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The Hub is a good idea and common practice, they sometimes call them concentrators, keep all the communications within the low-voltage network all talking to the Hub, then have it as a relay or store-and-forward configuration. Seen it where the hubs are just data colectors, and are either visited or dialed-in periodically.

I believe it was Ampy that made a large deployment in Italy with this concept and GSM radios for the hubs.

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thanks folks, this is an excellent idea,
I have not been thinking about this, because I'm not well familiar with a GSM and the other stuff.
first I will read some good books about this, then make a next step :wink: