Re: Another unusual plug and some other questions
 

Hi,
Is this what you were thinking of? I used to have the matching plug, but I think it's been lost in the mists of time. There are no markings on it apart from "RADIO".
Cheers, Pete:wave:

Re: Another unusual plug and some other questions
 

I've got a matching plug on my '30s GEC extension speaker.

My primary school had these sockets in every classroom with C&S speakers connected to them.

Nick

Re: Another unusual plug and some other questions
 

My school had 3-pin sockets of this type in some classrooms too. A 1952 Belling-Lee catalogue identifies the 3-pin plug type as being in accordance with BS666.

The 1936 Bulgin catalogue has 2 pin [unillustrated] and 4 pin [similar configuration] types, the 4 pin type being for use with speakers having energised field coils.

Re: Another unusual plug and some other questions
 

My primary school had the 2 pole versions with a switch box to select channels of radio. I think it was centre OFF one side PROG1 the other PROG 2. In practice it was always switched to the side which gave the 'Home Service' so we could cavort about to the exhortations of Miss Percival (Music & Movement), once a week. Heaven knows what would have happened had teacher's hand slipped and the 'Light Programme' been selected; the effect of those Beat Combos on our tender minds .......

Re: Another unusual plug and some other questions
 

Hi Gents, this type of plug was used in schools and homes in NE England as part of the Reddifusion "wired sound" system. It used 100v line distribution and 4 programmes were available. Selector switch was usually by a rear window and a resistive "chain" fader was fitted to the speaker box. This connected to the selector switch by the plug/ socket shown.

Ed

Re: Another unusual plug and some other questions
 

We had this in Rammy until the mid nineties Ed for TV/Radio. I think Dave Moll has the selector switch from my house on Bury New Road. I thought the signals came out on a 9 Meg feed [twisted pair] or have I got that wrong? The ref to a 100v line has confused me. Don't want to go off topic with this but I am relying on the "some other questions" aspect of the Thread Title to meet the regulations:D.
Dave W

Re: Another unusual plug and some other questions
 

The schools in our area had some sort of radio/gram hidden away somewhere and C&S speakers with switched volume controls. I thought they switched resistors but they could just have well been transformer taps.

Just seeing the connector re-creates the sounds ding-de-dong, ding-de-dong, DING-DE-DONG, DING-DE-DONG, BONG! Are you sitting comfortably?

David

Re: Another unusual plug and some other questions
 

Hi Dave W, 100v line was for radio, TV was on separate leads, probably twisted as you say and screened. From memory it was about an 8 meg signal.

Ed

Re: Another unusual plug and some other questions
 

Thanks for the clarification Ed. At least I wasn't entirely folowing the wrong "lead". :thumbsup:

Dave W

Re: Another unusual plug and some other questions
 

I picked up a few 1956 editions of Practical Householder last weekend and found this advert for "The King Pin".

Oddly at the same market but a totally unrelated stall, someone had one of these very plugs and a scrap of old fabric cord attached to it (covered in mud). The joker wanted £15!!!! So I bid him farewell.

Anyway, interesting ad nontehless

Re: Another unusual plug and some other questions
 

Surely fuses don't blow often enough for this to have ever been of any use...?

Re: Another unusual plug and some other questions
 

Oh yes they did !
Back in the good old days, when power sockets were rather a new idea, fuses blew regularly.
Some appliances used a full 15 amps and therefore got through 13 amp fuses regularly.

And of course mains voltages differed, I doubt that a 110 volt heater would have survived long on 240 volts, but many old 210 or 220 volt heaters got used in 240 volt districts and used 16 amps or so.

I remember a relative who had an old fashioned 3 bar electric heater in which I noticed that the elements seemed bright orange rather than dull red.
I found out later that the elements were designed for 200/210 volts.
They threw it out when moving to a house with the new fangled 13 amp sockets because it kept blowing fuses. It worked fine on a 15 amp plug, probably with a 20 amp fuse at the fuseboard.

Re: Another unusual plug and some other questions
 

Here's a 1906 Hubbell Catalog of US electric sockets and receptacles.

http://archive.org/details/Electrica...No.9August1906

Gene

Re: Another unusual plug and some other questions
 

Fascinating read Gene, particularly liked the table lamp, thanks for that link.
Neil

Re: Another unusual plug and some other questions
 

Thanks. I'm glad you liked it. This catalog also gave me a clear look into early American plug technology. I was told appliances could either be hard-wired or fitted with an Edison base. There might have been other plug-socket schemes,but Hubbell's won out.

It's interesting that he started with a tandem blade design, then for some odd reason settled on the parallel blade (NEMA 1-15 or 125V/15A) design that we have to this day for household use.

The tandem design was not discontinued,but assigned as a NEMA 2-15 or a 250V/15A plug.

For a while 120V outlets were designed to take both. Here is a 1940s era socket in my bathroom. 8-)

Re: Another unusual plug and some other questions
 

Hello forum. I'm newly joined. Attached is a quick sketch (from memory) of a British plug and socket that I'm trying to identify.

My childhood home was built some time around 1900. Each room in the house had one socket of the type shown, fitted to the skirting board.

Both plug and socket were heavy duty (about 1.75-2.00 inches in diameter), with large diameter pins. I think they were rated at 15A. I remember one plug was fitted to a two-bar reflector fire, another to a Cossor valve radio. Unusual features of the plug were the brass case, and the ‘goose-neck’ flexible metal sheath to provide strain relief (some had a moulded rubber sleeve instead). A pair of brass ears were held in place by a knurled cap, to ease removal of the plug.

I've never seen a similar connector in any other house, then or since. I've trawled the internet for some years now, hoping to see a similar example, but with no luck.

All clues gratefully accepted.

Re: Another unusual plug and some other questions
 

Hi,
It looks a bit like the industrial plugs & sockets that used to be made by 'Reyrolle'. The power station I used to work at used them for the 110volt portable power tool system. We also had a miniature version for the 25volt SELV hand lamps.
The 250volt version had a different keyway to avoid the wrong socket being used.
Maybe your house had a domestic version?
Cheers, Pete.:thumbsup:

Re: Another unusual plug and some other questions
 

That looks like it could be a derivative of the "Niphan" military/industrial-type plugs/sockets. They were also used extensively in the railways-world.

Re: Another unusual plug and some other questions
 

Definitely industrial, probably "liberated" from somewhere. Given your location, possibly a mine?

Re: Another unusual plug and some other questions
 

I have only just noticed #216 and the most interesting linked Hubbell catalogue, having been taken ill on holiday last year when it was originally posted.

In my earlier post #68 I mentioned Hubbell's patent US776,326. Pages 52 -57 of the catalogue feature "Multiple Attachment Plugs" similar to those shown in that patent, but modified for the then-new flat pin plugs. Pages 56 and 57 indicate that the illustrated example of a plug for a "receptacle of any ordinary type" shown in Figs 2, 3 and 4 of the patent, and which Hubbell implicitly acknowledges was already in use before his patent was filed in 1903, was called a "Chapman Receptacle". Google produced a photo of one here:

http://media-cache-ak0.pinimg.com/or...d8eba434e3.jpg

as well as a few examples of early literature where such receptacles are mentioned. Its contact arrangement is similar to the "Kliegl" connector that was used for studio/stage lighting well into the second half of the 20th century, but whereas the Kliegl has a resilient contact on the plug, the Chapman has resilient receptacle contacts.

If I ever get round to learning how to make entries on Wikipedia, I might correct the caption to the drawing of the early Hubbell plug of US 774,250 (filed on the same date as US 776,326 and showing the same type of plug) that, at the time of writing, appears on the "AC power plugs and sockets" pages. I am sure I saw the drawing and caption some years ago in an account of Hubbell's history that used to appear on their web site, and which has since been revised.

Thanks, Gene, for clearing up that mystery!

Re: Another unusual plug and some other questions
 

Tractorfan, G6Tanuki, AC/HL (220, 221, 222)...

Many thanks for the suggestions. Our landlord in the 1950s was never anxious to modernise - we still had Victorian fireplaces and a cast iron cooking range when we left the house in 1969 - and he had family links to both coal mining and railways, so an industrial origin for the plugs and sockets sounds very likely.

The sockets were star wired back to one of two cast metal quadrant lever boxes above the kitchen sink (the other being for lighting). The sockets had no earth provision, despite the fastening screw on the plug case, which 'captured' the appliance earth wire.

I will now investigate industrial connectors!

Re: Another unusual plug and some other questions
 

I bought a few small catalogues last week, in a Dubilier one from 1954 I found this page with the range of radio interference suppression plugs they offered.

David

Re: Another unusual plug and some other questions
 

Not allowed in the USA? Maybe so, but on a recent trip there I was surprised to see these installed in a coach (Megabus) for the purpose of passengers charging their phones and tablets.

Charging points at Heathrow and Gatwick have UK and Schuko next to each other nowadays.

Rather dangerous thing to do. There are still homes with 5 amp round pin sockets often for portable lightning all controlled by a single switch. Nothing to stop someone plugging in one of their 24v DC appliances.

There was a similar problem in Australia where portable generators were being sold with a 12 volt 2 pin socket with the same outline as the 2 business pins of their standard 240 volt socket (I've seen them here as well). The authorities soon put a stop to that with a recall and generators there now have the standard Australian low voltage (ELV here) 2 pin socket which has the 2 pins at right angles to each other.

Re: Another unusual plug and some other questions
 

I would consider it foolhardy to use old style UK round pin sockets for 24 volt DC if they were already used in the same premises for AC mains.

For relatively new or re-wired premises though, the old round pin 5 amp and 15 amp outlets are ideal for 24 volt DC supplies.
I have seen the 15 amp sockets used for intermittent loads of a lot more than 15 amps, not best practice but they never even got warm.

Re: Another unusual plug and some other questions
 

The pins on 15A plugs are quite heavy and will be able to absorb quite a bit of heat over a short period but the user must make sure enough time elapses before the next load is applied.

Re: Another unusual plug and some other questions
 

As the standard US flat pin plugs are rated at 15A, a UK 15A plug should be capable of carrying currents far in excess of its nominal 15A.

My GEC catalogue of 1911 explicitly says as much about its range of 2 pin plugs that correspond with the old UK standard 2A 5A and 10/15A 2 pin plugs: "The terminals are of ample dimensions, and the complete plugs are guaranteed to permanently carry currents far in excess of their rated capacities".

Re: Another unusual plug and some other questions
 

The current limitation is more likely to be the integrity of the limited area contact between the socket and the pin than the csa of the pin itself, especially when old springy bits relax.

Re: Another unusual plug and some other questions
 

I did a rewire (back in the 90s) in which the client wanted their table lamps on a special circuit on a dimmer switch (anyone remember incandescents? :) ) and I installed the circuit for that as 5A sockets, so they couldn't inadvertently plug anything else into it. Needless to say, in this domestic dwelling they didn't use 5A sockets for anything else.

Also, it's a bit off topic but worth noting in discussions of actual current capacities that twin 13A sockets are not rated for 26A continuous and will, after sufficient use with a 6kW load, Halt And Catch Fire.

Re: Another unusual plug and some other questions
 

Following on from #228, last week we had a midweek break at Warners on the IOW. Our bedside lights were connected via the old style 3 pin 5A plugs and sockets. I have previously found these used in hotels to allow standard lamps to be controlled via wall or bedside switches, but in this case the (unswitched) sockets were not controlled by wall switches, the lamps being switched by in-line flex switches. No fuse box in the chalet, so I couldn't check the fusing arrangements!

We could have done with a couple of incandescents: the bedside lamps were fitted with base-down ES-base GLS LED lamps, made by BELL. No problem with RFI on any band until my radio got closer than 4" (Spain came through loud and clear on medium wave), but as bedside lamps they were dire. This type of lamp is evidently designed for burning base up in a ceiling light fitting as light is only emitted from the hemisphere opposite the base. As a consequence, while the light reflected from the ceiling made the room bright enough, very little light came down where it was needed to read in bed. Rough measurements with the exposure meter of my camera indicated the downward illumination was less than 20% of the upward. Must remember to bring a couple of my own tungsten lamps in BC and ES bases with me next time we go away.

Re: Another unusual plug and some other questions
 

Sorry to go back a few pages, but something of interest in this day and age:

Just this minute made this on my desk at work! Was surprised to find we still have a live Walsall ring in our TV studio area. I'm currently tasked with converting an old cupboard to a recording suite. Just a couple of Walsall's on the wall so this will provide temporary power for my tools / radio whilst I work; until rewired further down the line.

Re: Another unusual plug and some other questions
 

Is what trickles out of them normal mains? Walsalls and the like were often used when there was something "odd" about the supply connected to them. Backup, different voltage, clean, or whatever.

Re: Another unusual plug and some other questions
 

Yeah; the room hasn't been used for TV stuff for at least 20 years, but back when it was put in in the early 70's it was there to provide some kind of clean supply and forced seperation from domestic circuit for certain bits of kit - on a seperate phase i think.

As the room changed and was no longer used for TV stuff (this is a college so it changes a lot) the supply for these was removed, and at some point it has just been tagged onto an MCB in the domestic board.

Re: Another unusual plug and some other questions
 

Hi,
I've got a Walsall gauge plug & socket like that. The socket is actually made by Walsall and the plug is marked 'Sainsbury's' but carries no maker's name. The plug also contains some kind of suppressor or vdr in the cover connected between all three pins via springs. It may be intended for EPOS use (Electronic Point Of Sale). The base of the plug is moulded in such a way that it could accept another fuse holder on the neutral side if used for another variant.
Cheers, Pete.