[crawf1982]

I though this might be of interest.

A company called VPhase have developed a device that stabilizes domestic mains voltage at 220V. See the website for full details.

I have been having problems with bulbs blowing and small electronics getting fried at home (notably routers or their power transformers). I tested my sockets to see what voltage I was getting and on average it is 246V. I looked into this and found that the legal limits in the UK for domestic voltage range from 207V to 253V. After I had finished laughing hysterically at that discovery I went on the web and looked for a solution. The VPhase VX1 seems to be it.

Having a constant voltage would surely be better for all electrical appliances, but for video/audiophiles I would think it would be essential.

I have contacted VPhase to express my interest in their product and volunteered to take part in any field testing they are doing. I think the VX1 is due to be available in early 2009. Maybe we should look into an AVForums Power Buy!!

Cheers,

Dave

[ZippyCat]

Actually it’s not quite a daft as it may first seem, even if I admit we were extremely sceptical at work about claims made by a similar product from another manufacturer.

At the moment there are several large multinational companies installing similar types of technology into their buildings (obviously on a much larger scale) that steps down the voltage to 220V, filters harmonics and provides a form of power factor correction.

As it happens a couple Engineer’s from work attended a technical seminar yesterday that relates exactly to this kind of technology. There were representatives from some major companies who have confirmed that since installing this type of technology, their electricity bills have reduced in the order of 8 to 15%. At the seminar there was even a major electricity provider who is planning to install similar equipment between their substations and domestic premises.

It was however admitted by the company that it is not cost effective to install their device on a single dwelling, as the payback is in the order of 15 years, although it is cost effective to install it on a block of dwellings such as flats etc.

I purposely have not mentioned any names above as it would not be appropriate for me to do so (just in case someone asks).

[JohnDenholm]

I found this thread using the search and I realise its old etc...

Saw this on the TV today and Im wondering if since these last posts anyone has had any experience with them? Are they too good to be true or do they work?

Online they look to be about £300inc VAT then however much it would cost to fit one of these things which would suggest you would see a return in much less than the estimated 15 years above. Just wondering because a 10% saving if its true is actually a lot of money in this day and age, especially with a house with 2 plasmas, various sound systems and computers.

VPhase - Voltage Management - VPhase VX1

[crawf1982]

Since my original post I have actually completed a self build project. I have had a VX1 installed and I can confirm a constant voltage of 220V from the sockets. For comparrison, I got 247V from the sockets in the house I moved from!

[JohnDenholm]

Cheers for such a quick reply.

I take it as its a new build you couldnt say if it was saving money over a regular supply without one?

[crawf1982]

Well - as the voltage being supplied to the sockets is lower I assume there will be some saving on the electricity bill.

There are also the long term savings to consider though. Having a constant voltage of 220V rather than 247V will prolong the life of any large household appliances that are on all the time (fridge, freezer, etc) as well as small appliances with transformers.

[JohnDenholm]

Well worth looking at then, cheers!

[S2Tigger]

Currently doing a self build project, read this and did a bit of internet searching....what a minefield!!

Did find a reference to this document

I am not sure it would be a good investment or not....I suppose it is one of those topics where every person has a view....

Am open minded to this at present, wouldn't take a lot to get it installed as electricians are on site....will do some more digging

Darren

[robin1989]

anyone able to shed light on how big these vphase units are and is the 10-20% savings are true as if so that would be great for us as our bill for electric is about £2000 a year. also how would i test the output from a socket as im guessing shoving a standard multimeter in the socket isnt a good idea

[crawf1982]

Vphase unit size:

What size is the VPhase unit - VPhase

I can confirm constant voltages of 220V at our sockets.

A good way to test one of your sockets would be to plug in a figure of 8 power lead and then use a miltimeter to read the voltage at its contacts.

[hodgelv]

Originally Posted by crawf1982

Vphase unit size:

What size is the VPhase unit - VPhase

I can confirm constant voltages of 220V at our sockets.

A good way to test one of your sockets would be to plug in a figure of 8 power lead and then use a miltimeter to read the voltage at its contacts.

DO NOT test for voltage in this way, it is a very silly idea. most multimeter test leads do not have finger guards so slipping when inserting the probes is a very possible risk. Although, unfortunately I cannot recommend a safe cheap/ free alternative for the average house holder.

[BlueWizard]

There are a couple of methods of power line voltage regulation, the most common of these being a Ferroresonant Transformer.

The resonant effect means that if the voltage on the input falls, the voltage on the output rises. If the input voltage rise, the output voltage falls. Consequently a uniform fixed voltage is maintained on the output.

But, there is a limit to how wide the input can vary in order for the output to maintain that fixed voltage. Also, the devices are very frequency dependent, if the power line frequencies varies, it throws off the regulation. One percent variation on the line frequency results in a 1.2% variation in the output voltage.

The drawback is that these transformers are relatively large and tend to run hot.

The other method is to transform the input into a DC voltage, then convert is back to a regulated fixed AC voltage on the output. These run cooler, but can be noisier (electrically noisier). And there is also a limit to how widely the input can swing while the device is still able to maintain regulation on the output.

This is the type typically used in Uninterpretable Power Supplys (UPS) for computer networks.

Just a little FIY.

Steve/bluewizard

[Andy8421]

I have been having problems with bulbs blowing and small electronics getting fried at home (notably routers or their power transformers). I tested my sockets to see what voltage I was getting and on average it is 246V. I looked into this and found that the legal limits in the UK for domestic voltage range from 207V to 253V. After I had finished laughing hysterically at that discovery I went on the web and looked for a solution. The VPhase VX1 seems to be it.

Crawf1982 - 246v is fine. Any mains equipment will be designed to cope with at least the UK range (230V +/- 10%). Most electronic devices with switcher supplies go down to at least 110V. Any problems you were having with device failure is not due to mains at 246v.

S2tigger - The energy saving argument for mains voltage reduction is not a matter of opinion, it is pretty much nonsense. The paper you linked to explains this well:

http://itee.uq.edu.au/~aupec/aupec04.../PaperID77.pdf

Just to play devil's advocate, lower mains voltage will lead to lower power available to the output stages on your power amp. 10% down on mains is 10% less headroom for the amp. Given the daft money spent by audiofools rewiring their house and replacing their mains cable with railway line, I can see a venture supplying products to boost mains voltage to the max 253V permitted in the UK. "Give your amp more headroom, dont be satisfied with sub voltage mains, the MainsBooster will give you the power your amp was designed for.." and so on and so on.

[BlueWizard]

"Just to play devil's advocate, lower mains voltage will lead to lower power available to the output stages on your power amp. 10% down on mains is 10% less headroom for the amp."

Not necessarily. This is hard to explain, so let me do it by analogy. Using a linear DC voltage regulator, as opposed to a modern switching regulator, your transformer delivers more voltage than the output of the regulator. For example, when AC is converted to unregulated DC, and that is fed into the voltage regulation circuit, we feed 40v in to get 30v out, giving us a reserve of 10volts.

So, the input, in this example, can drop by, not quite, 25%, and the output can still maintain 30 working volts.

Now, to try to describe how this works in Switching Power Supplies is way too complex, but the same principle applies, the primary unregulated DC power his higher than the output DC power, so there is something of a reserve.

A change of 10% would be about 24 volts on the AC mains, by the time that passes through a step down transformer, it is more like 3 volts, and even less when it is converted to DC. So, the effect on the unregulated DC voltage is very small, and within reason, has no effect on the regulated DC voltage.

In terms of Power; Power In, more or less, equals power out. As long as the Regulator has voltage to work with, and as long as the Power Lines, and the Power Supply have current to be supplied, the amp won't notice the difference.

However, there can be surges or ripples or short term drop outs on the mains that can go far lower than is typically allowed. You could have a momentary drop below 200v just as the amp is trying to send a surge of current to the speakers, and this could cause a reduction in available current.

Also, how much voltage you have is related to the season and the time of day. When people come home from work and turn on all kinds of electrical appliances and air conditioners, the mains voltage is usually lower. Mid-morning, mid-afternoon, late evenings, and the middle of the night, the voltage can be higher; in other words, during off peak times.

Also, how far you are from the power source can make a difference. People on the end of the line tend to have poorer quality power; more noise, more voltage fluctuations, etc....

Just a few thoughts.

Steve/bluewizard

[ianmacd]

[QUOTE=Andy8421;14479312Crawf1982 - 246v is fine. Any mains equipment will be designed to cope with at least the UK range (230V +/- 10%). [/QUOTE]

UK harmonised range is actually 230V +10%/-6%

[Andy8421]

UK harmonised range is actually 230V +10%/-6%

Ian,

From Wikipedia (not a pefect source to be true):

"Voltage tolerance of 230 V +10%/−6% (216.2 V to 253 V), widened to 230 V ±10% (207 V to 253 V) in 2008"

Link here:

Mains electricity by country - Wikipedia, the free encyclopedia

Andy.

[Andy8421]

Steve,

My post was tounge-in-cheek, but I am afraid I need to take you to task a little over your reply.

A 10% change in mains voltage will have a 10% change in unregulated DC level. The nominal voltage change for the lower voltage will be smaller, but 10% is 10%.

Rectified AC driving a large storage cap can be thought of as a series of narrow, square wave charging pulses, current flowing only when the instantaneous AC voltage exceeds the voltage on the cap. All short term transient power requirements of the output stages are met by the storage capacitor, the AC waveform only supplies average power.

Unless I am mistaken, my old Naim Nait uses a regulated power supply for the pre amp stages, but an unregulated supply for the poweramp output stages. I believe this to be true of most hifi poweramp designs.

[ianmacd]

Originally Posted by Andy8421

UK harmonised range is actually 230V +10%/-6%

Ian,

From Wikipedia (not a pefect source to be true):

"Voltage tolerance of 230 V +10%/−6% (216.2 V to 253 V), widened to 230 V ±10% (207 V to 253 V) in 2008"

Link here:

Mains electricity by country - Wikipedia, the free encyclopedia

Andy.

Not sure where they got that from as ESQCR 2002 states in regulation 27(3):

(b) in the case of a low voltage supply, a variation not exceeding 10 per cent above or 6 per cent below the declared voltage at the declared frequency;

ESQCR has had 2 ammendments since 2002 in 2006 and 2009 and neither seem to update that regulation.

[BlueWizard]

Originally Posted by Andy8421

Steve,

My post was tounge-in-cheek, but I am afraid I need to take you to task a little over your reply.

A 10% change in mains voltage will have a 10% change in unregulated DC level. The nominal voltage change for the lower voltage will be smaller, but 10% is 10%.

...

Too bad that don't make a tongue in cheek emoticon.

What is 10% of 230v? It is 23 volts.

What is 10% of 40V? it is 4 volts.

Is the result of those to calculations the same? Didn't think so.

But yes, if it falls 10% on the input, more or less, sort of, it falls 10% on the output. But you are passing though a step down transformer, so as illustrated, 10% on the input is not the same absolute number on the output.

And, that 4 volt loss in unregulated voltage is still within the reserve window that allows the 30v regulated voltage to continue on unaffected.

The part about Storage capacitor is right. But it is complicating an already complex matter. Because the caps are literally on the regulated output, indeed they do supply short term current, that eases the load on the actual regulated voltage, and that stabilizes the output voltage in the short term.

But if the capacitors are drained, then need to be refilled. Hopefully this happens during a period of lesser demand output load.

Personally, I suspicious of any line voltage filter that claims "Voltage Stablization" unless I know what the internal workings are. "Voltage Stablization" is a some what ambiguous term, and I would be leery until I knew exactly what was going on inside.

Steve/bluewizard