Proposed new style household sockets.

[ColinB]

Originally Posted by Lucien Nunes

Of course, the UK was not a good candidate for conversion to unfused plugs due to our widespread use of ring final circuits. It inspired me to invent a socket-outlet that included an variable overcurrent protection device that was automatically adjusted by the type of plug engaged

Have you got any more info on these, Lucien? I seem to remember Gerry Wells mentioning this years ago. Did it ever get prototyped, or into production?

Thanks,

Colin

I would guess that most 'electronic' stuff these days will work with 100 to 250V AC or DC as an input, this does give the possibility of a float charged lead acid battery supply for all the home. The only thing of importance that will be affected is the kettle, even then it will only be a timing issue.

A new sort of 13A plug with one pin a wee bit smaller (say live a bit narrower) would fit in existing sockets and the 'new' variable voltage DC 'narrow pin' sockets, reverse compatability.

[Lucien Nunes]

Running DC for SMPSUs in tandem with AC could be problematic. Whilst the wall outlets could be one-way interchangeable as you describe, other connectors downstream such as IEC C13 would fail to carry over the distinction and one might end up with C13-AC and C13-DC cordsets being used indiscriminately. Also, many accessories in use today (including ordinary rocker switches, microswitches and the cutout in the kettle) are unsuitable for DC due to their slow break and small contact separation.

Distributing ELV DC to avoid lots of small SMPSUs is attractive, but could end up using as much copper as the mains wiring. There are also snags if equipment sharing a DC bus is interconnected, e.g. a computing device and sound system. In most equipment, signal common is connected internally to DC -ve, which can result in DC circulating through signal interconnect screens. If there is ripple or noise on the load current, this can induce noise in the signal leads. In the event of a faulty connection in one DC -ve lead, the entire load current then diverts through the signal interconnection and this can fry PCB tracks etc. Both of these problems arise periodically in my work, the usual solution being to isolate every unit from the bus with a separate DC-DC SMPSU, taking us back to square one.

I propose mechanical power distribution. If it was good enough for busy factories for 200 years, it must be a commercially viable solution. Small lineshafts could be erected in convenient places around the house, to which gadgets could be connected with nothing more than a rubber band. The appropriate dynamo would be concealed within the gadget, leaving just the pulley projecting...

Colin - I made some experimental devices but nothing resembling a full prototype. I was too young and inexperienced to realise that the system would have been too expensive to be universal, and thus would be self-defeating.

[happytiger]

Originally Posted by Lucien Nunes

I think there was some confusion when IEC60906 was proposed. Some people thought it was an existing 'foreign' plug that was being foisted on us, rather than a new standard intended to supersede those too.

It was described in detail in an MK booklet which I received some time ago,based on the IEC connector, never caught on, it appears that the British BS1363 is here to stay!

[Rhgbristol]

Yes
Mk issued a booklet about it in about 1976/77 entitled something like 'proposed European plug and socket system'

I remember writing to mk's then managing director, a guy called Jim Fallon, who sent me a copy. It was a very well printed book, a5 sized from memory, with very good glossy photos.

The proposed plugs, and sockets were not quite like current iec kettle connectors, but longer and thinner.
There was a two pin and three pin version of the same plug.
There was also a four gang socket version, which was the same physical size as the currentl style bs1363 twin socket.
Have not seen the book for years - must of thrown it years ago.

[kalee20]

Originally Posted by Lucien Nunes

I propose mechanical power distribution. If it was good enough for busy factories for 200 years, it must be a commercially viable solution. Small lineshafts could be erected in convenient places around the house, to which gadgets could be connected with nothing more than a rubber band. The appropriate dynamo would be concealed within the gadget, leaving just the pulley projecting...

I love it.

And low-powered devices could be powered in an emergency from a hand drill; medium-powered ones from an exercise bike.

[G6Tanuki]

Philosophically, I'd like to see more use of 3-phase AC supplies in average domestic environments: specially if the-powers-that-be drive us down the path of 'renewables' where we can't guarantee consistent pricing for power across the daily demand-curve.

3-phase would be great because it would let you grab massive amounts of power for short bursts - for bulk water-heating - when the wind-turbines/solar-stuff was instantaneously providing a superabundance of cheap power and the grid was needing somewhere to dump it.

The downside of this would be that it needs people to have old-fashioned hot-water-tanks rather than the more sensible 21st-century heat-just-what-you-need-when-you-need-it approach.

[Tractorfan]

Hi,
Three phase supplies to domestic premises is (or was) quite common in France. It was mainly for electric heating and ovens. where limited overhead capacity was available. A few houses which have been rewired often have had two phases disconnected.
I heard a tale of an ex-pat whose house had three phases rated at ten amps each. Assuming that he would get 30amps by connecting them together, he did so and blacked out most of the village!
Cheers, Pete.

[emeritus]

In my late brother-in-law's house in France, all that had been done to convert the original 3 phase to single phase was to replace the original 3 phase master switch by a single phase switch and circuit breaker, and connect all three phases to the master switch, leaving the original fuses and wiring untouched. The original 20A 3 phase sockets in the shower room (intended for a washing machine) and cellar were left as they were. He never tried using those sockets, which were still left live. Presumably had he connected a three-phase appliance that did not include a 3 phase motor (such as an electric cooker) it would have worked, but the return (Neutral) would have been somewhat overloaded, as the neutral wire was of the same size as the phase conductors. His cooker was connected to a conventional 20A single phase socket, but the manual showed wiring connections for both single and three-phase supplies. (The new owners intended rewiring to the current standards.)

In the attached photo of the shower room socket, the conventional French socket was put there for the photo to give an ideas of size.

[Tractorfan]

Hi,
You can still buy domestic 20amp three phase plugs, sockets and even trailing sockets here, either with, or without a neutral connection. Also available are 20amp single phase plugs & sockets and adaptors to allow standard 16amp plugs to be used.
Cheers, Pete.

[julie_m]

While working on a camp site in the South of France, I had the unenviable task of getting an ancient chip fryer up and running in time for the snack bar opening that evening. It used a 20 amp, three-phase supply with no neutral; the thermostat switched a contactor with a 400 V coil wired across two phases, which switched the supply to the delta-wired elements. Unfortunately, the contactor was so ancient that replacement coils were unavailable; and the only whole new contactors available from the local electrical factors had 230V coils. I bought one anyway, put a replacement 400V coil on back order, and ran a temporary supply from the nearest 230V socket to the thermostat circuit. And pommes frites were back on the menu that evening! (And I picked up the live from that socket, rather than using one of the phases from the fryer; because if I had done that, then the neutral pin would have become live -- via the thermostat and contactor coil -- when the fryer cooled down.) A week later, the new coil arrived and I was able to remove the bodge wire.

One great Advantage of three phase for SMPS is that you wouldn't need an input smoothing capacitor

[Herald1360]

Originally Posted by ajs_derby

And pommes frites were back on the menu that evening!

Well done, that man!