HiFi Subjectivist ¦ Audio Forum ¦ NVA User Group

Times are a changing!
I have moaned officially three times about the quality of my mains electricity, and each time got further up the chain to in the end talking to a senior engineer in the national grid. He asked me to give the problem for hi-fi users in the way we have to deal with the distorted and malformed wave form we have to put up with at the moment. So he got that. It seems he is an expert opinion on a new committee that is looking into the future including the post Brexit considerations. A new set of rules i.e. a new British Standard is being drawn up.

The current ring circuit British standards including BS1363 is inadequate for the future of home generation and control of our electricity supply. At it simplest sun or wind generation, but the real future is smart meters that allow you to pick and choose the cheapest times to connect to the grid and to charge power walls. Lots of companies now making them but only Tesla is pushing the process.

https://www.tesla.com/en_GB/powerwall

Also other manufacturers are joining in as with other car companies, even one using batteries no longer strong enough for cars as power walls don't need that, so using recycled car batteries (not the big 12v ones), these are the low voltage power packs.

Power walls IMO will solve most of our problems we have now as long as effort is put into designing clean and accurate and fast conversion points at each end AC to DC in and DC to AC out. That is the only potential source for problem with audio.

Now all of this makes the BS1363 redundant as rings are not the most suitable for this new way, and it is finally being realised that ring circuits are a bad mistake and potentially dangerous as they can sometimes fail in an unsafe condition and cause house fire. So it looks like the new regs will take us back to radial circuits, and ring circuits will be banned in new installations.

So a big about face is on the cards for the future and power walls will get cheaper as more and more electric cars make the batteries cheaper and more available. At some point the intelligent house that controls its own power requirement will be here and that can only be good for hi-fi equipment.

So back to the original question at Wigwam. I replied that yes a radial circuit is better sounding but not so much because of the system but because you can get rid of the daft badly designed BS1363 plug, our square pin 13amp, and instead use our *British Standard* plug for radial circuits BS546 15amp. If someone installs a radial circuit using 13 amp fused plugs they are simply daft and throw away the benefit. nothing I have said breaks Wigwam rules on the matter which I quote below. Yet my posts have been removed.

ELECTRICAL SAFETY
In line with regulations, no posts can be made that encourage or suggest any modifications to mains electrical wiring, including but not limited to fuses, cables, etc. that do not meet relevant standards. Posts in the DIY section assume other members have a reasonable knowledge of electrical safety, but equally any posts promoting or suggesting any potentially dangerous act will be removed.

Note the high lighted bit which I have not broken, so I afraid once again we are into BIASED MODERATION

Hopefully all this earlier in the post means in time it will get better for us and we are not trying all the time to compensate for our shit mains as with DC blockers, isolation transformers, and balanced mains units. But we will have this for a long time, it will be probably be 5 years before the new regs come in.

Did you ask what plans are in hand for the standards that will govern the inverters in use? it will gain us nothing if 5% distortion is acceptable from the inverters. We will just replace an old problem problem with a new one.

No he gave me no indication of any decisions apart from it is highly likely we will revert to radial circuits as the rest of the world has. Sadly ring circuits will be around for very long time.

It is an on going process, committee.

I think it is up to us to design hi-fi ones, and I vote you as the best person to design one.

and I vote you as the best person to design one.

DC to AC high efficiency mains converters are so far from my skill set as I can think. I remember trying to repair an audio quality UPS once, rarely have I heard such a loud bang when a mosfet vaporised itself. I propose we drag Colin W out of retirement, its right up his street.

When I worked for Harmen and Simmons we designed a 100KVA mains conditioner, using a isolated transformer set to resonate at 50Hz this kept the voltage constant but the output was not a sin wave. A addition choke and cap was used on the final stage to produce a 50Hz sin wave. This was a simple solution and could be made smaller i.e. 5KVA, The taping was done with Back to Back Thyristors but this produced high levels of cross over noise, now with the R00T2 SSR I designed which has very low cross over distortion this noise could now re reduced to 50dB from 100dB see graph. Since then I have had on the books a better design which give me 20dB. All at 50A 240VAC nominal. Also the new design loses are at 10A only 6W as to 14W on the old design.

https://www.root2.ltd.uk/

I have been having a hunt to see what the current state of inverters is, and its got a lot better than the last time I looked. At least as good as what we are getting now from the wall, and I would say potentially better. This sort of thing gives me some hope.

http://www.ti.com/lit/an/slaa602a/slaa602a.pdf

And I might consider trying one of these