On Nov 25, 2011, at 20:28, Richard <legalize at xmission.com> wrote: Oh yeah, power cables. I have so many and forget that other people don't; sometimes I'll go somewhere and don't bring the cord and get weird looks when I act surprised that my hosts don't have spare computer cords. Interestingly enough, we got a new coffee percolator recently that has an IEC cord. That's very convenient, because replacements for the old Farberware ones were getting hard to find. I understand, though, that this is common practice in Europe for tea kettles? I've taken a liking to the Sterilite drawers that you can buy from Target relatively cheaply in stacks of three. They're stackable beyond that (up to at least six comfortably) and come in a variety of cheerful colors. I've got bins for power cables, power strips, USB, Ethernet, serial, ribbon and lots of other categories. -Dave

don't; an is draw didn't come I went into a hardware shop recently and asked for an IEC lead. I got blank looks until I said "you know, a kettle lead", then they knew immediately what I wanted :-) Rob

Indeed. Those are everyhwere here. I even have (and could probably find) ones with Aemrican (117V and 234V) plugs, German Schuco plugs, and maybe others... ^^^^^^^^^^ What does that look like ? Yes. Well, actually the conenctor on an electric kettle over here is the 'hot condtion' one with a notch on the socket and ridge insdie the plug. Originally, the 'normal' one, as used on computers, was rated at 6A, the 'hot condtion' one at 10A. I could never work out why, the contacts were identical. Now it appears all are rated at 10A. A common term for the sort of mains lead we're talking about, whether 'hot condition' or not, is a 'kettle lead'. Older UK electrica kettles had one of 2 conenctorm The older one was flat with 2 roudn pins on the kettle. The outer shell of the socket part had spring contacts which conencted to the kettle body whenm youp lugged it in, providing the earth connection. The somewhat later one was a circular connector about 3cm in diameter with 2 round plins for the live and neutral wires and a flat earth pin. There have been others too. As for electronic equipment, just about everything modern uses one of the IEC 320 connectors. The one we've been talking aobut, the smaller 'figure of 8' 2 pin one (used on radios, tape recorders, non-earthed laptop power brickes, etc) and it's 3 pin version (used on earthed power bricks). BEfore those were common, there were a series of circular connecotrs, in at least 1.5A and 5A versions with 2, 3 or 6 round pins. SOem of the older ones don't meet safety standrds now, becuase you could unscrew the cover of the cable-mounted part iwthout needing a tool and expose live terminals. But tater ones were held together with screws, and last time I looked were still being made. -tony

Oh, absolutely. The 'hot condition' sockers. at least the moulded ones, are a different material to the standard ones. Yes, but that's not the point I was making. The electrical parts -- the contacts, are the same in the normal and the 'hot codition' ones, and yet the former was rated at 6A and the latter at 10A. Why the difference? Now, I suppose the hot condtion ones could stand the contacts running hotter so they could carry more current, but IMHO if the contacts of a connector are getting that hot, it's underrated. -tony

Sure, that was the original reason for the 'hot condition' version of the connector. One that could be used in an hot envrionment, such as on a kettle. It's a waste of power, and it also means there's a voltage drop across the pin/socket. This mightcause problems. True. My real qustion is that originally the 'normal one was rated at 6A, the 'hot codition' one, which is identically electrically, was rated at 10A. Maybe the latter could carry more current becasue it could get hotter, but I don't like it... Now, a lot of 'normal' ones seem to be rated at 10A, although they appear to be unchanged from the older 6A versions. My first guess is that the original 6A rating as a very conservative one. -tony

Very liekly it does. No, don;t do that. The 'Hot condition' connector is designed to withstand the higher then normal temperatures produced by such devices, the ridge is there ot prevend you from plugging a normal cable in. A normal cable may well soften enough to be hazardous. You can get 'hot codition' sockets quite easily over here. I would be suprised if Farnell didn't sell them (and thye have a US presense IIRC). Over here, equipent must genrally either be 'double insulated' (which means even in the event of a failure, exposed metal cannot become life) or earthed. There is one exception to this -- a single-insulated non-eartehd device that can still be legally sold -- christmas light strings (!). For homebrew stuff it's generally easier to earth it than to ensrue it meets all the requirements to be double insulated. A lot of modern commercial devices are double-insulated and have a 2 wire mains lead), one reason is that such devices are stil safe if the earthing on the socket is dubious... I don;t know when they became common over here. The older-style round pin sockets existed in 2 and 3 pin versiosn (and were incompatible, in that you couldn't plug the 2 plin plug into the 3 pin socket or vice versa). All ring main socekts (the '13A' BS1362 one) are 3 pin, I think they were introduced in 1948. I am also darn sure that fititng 2 pin non-earthed sockets is against the regulations now (as it should be!). Yes, I've seen such adapters. I've also seen a moulder US 115V plug wit hthe earth pin cut off, presumably so it would go into a 2 pin socket. Ouch!. Ther'es one possible hazard over here. The normal domestic power cirucit is called a 'ring main'. As the name implies its a ring of cable and you can fit as many 13A socket outlets onto it as you like (there are restrictions as to the floor area it can cover, etc). The cable is rated at 21A (IIRC) so the circuit can theoretically carry 42A (2 paralell paths as it's a ring), it's fused at 30A in the 'consumer unit' (aka fuse box)). Anyway, since 30A is a ridiculaously high current rating for portable appliances, there's a cartridge fuse in the plug. These exist in a number of current ratings, but only 3A and 13A are commonly used. The first problem is that most 'loose' plugs are supplied with a 13A fuse in it. It's not uncommon for such a plug to be fitted to a piece of electronic equipment which should be prtected with a 3A fuse in the plug. I can't be the only person with a large jar or 13A fuses that I've removed form such plugs. Actually, the plugs _are_ available with a 3A fuse pre-fitted, but just try finding anyone who stocks them. The worse hazard is that I have a mains lead which has what appears to be a UK 13A plug on one end (and will fit a normal UK mains socket) and an IEC 320 connector on the other, but _no_ cartridge fuse in the moulded-on plug. That is IMHO lethal over here. I believe it was made for use in some other country which was once under British rule and which adopted the same mains socket on a 15A radial circuit (one cable per socket outlet, each socket indvidually fused in the consumer unit). In that application you don't need the fuse in the plug. -tony

On 11/27/2011 2:17 PM, Mouse wrote: Also check just to see, that the power does come from the fuse box... you never know as you could get it from the neighbors window instead. I have heard that happen in a older home. :(

Mine was cut off, you cna see a stub of the pin in the moulding. Can you dismantle the power strip to make sure hte ground is connencted between the sockets and to the input cable at that end? If so, why not just rempalce the plug? -tony

I've certainly seen a lot of them, includign the higher-current ones. I think my Zilog S8000 machine has such a mains connector. Actually that's true. The electrical safety rules came from the IEE (Institute of Electrical Enginenrs, now renamed) I beelive you can break the rules for prototypes,homebrew devices, etc. Howev,er I try to avoid doing so (obviously there are times when prototyping that yuou have live parts exposed, etc). I do amke sure anything I build is properly earthed. 204V shocks are unpleasant if you're lucky, if you are not lucky, you don't feel a thing -- ever again. As I mentioned in anotehr message, I've seen that :-( Err, yes... As an aside, the common mains plug/socket over hera has rectangualr pis, specifically to make it incompatible with the earlier round pin ones. Yes. that type is allowed, in fact it;s the only type of socket allowed in a bathroom (defined as a room containign a fixed bath or shower). The reason is that the socket contains a double-wound isolating transformer (abotu 20VA rating). Some years ago one of the 'pounds shops' (equivalent of dollar stores) over here had some of said sockets on sale (I guess they were bankrupt stock or something). I bought all I could find. A 20VA mains isolating transfomer (with the cecondary tapped at 115V, since said shaver sockets often ahve a 115V outlet too) was well worth a pound ;-) Tha'ts the main problem IMHO. Said adapters are only safe if the screw is earthed (and if it is, why wasn't a 3 pin socket installed?). IF the screw is earthe,d then of course the adapter is fine, it's equivalent, really, to a 3 pin socket. Yes, they exist over here too. The circuit is beacially a delta of neone and series resisotrs, often with a couple of otehr lad resisotrs so tht 2 neons in series will not strike. They indcate any signle wire being disconencted, lvei/neutral swapped, etc. They're not ahrd to get, and there have been projects to build then in the magazinse over the years. Probably for the same reason that not everyone has a multimeter, a solderign iron, etc :-). The built-in fuse is a nice feautr,e sure. It means that a failure of the plugged-in device, even a dead short in the cable, notmally only blows the fuse i nthe plug and you don't have to go to the consumer unit to change the fuse. I wonder if that cable was actually intended for use in the UK, or in whichever country it is that uses said socket son a radial circuit? I would not be happy using it over here, unless plugged into a fused mult-socket block (there is a common multiple socket over here, what you cal la power strip, whth 4 13A sockets in parallel and a 13A fuse on the incoming feed (which is generally connected to a 13A plug). You use them to run several low-power devices from one wall socket, of course. In that case, an unfused plug plugged into such a board is not a major safety hazard, since the incoming feed is fused at 13A). -tony

We get those over here too, with a 13A BS1363 socket on the back, which looks as though it would alsdo take a 2 pin shaver plug.. They often come as a set of 2 adapters. One has the flat pins which can be rotated as you describe to fit USA or Australian sockets -- this type makes no connection to the rarth pin. It has moulded into it 'Class II appliances only' [This meand double-insulated - -ARD]. The other fits the German mains sockets, it has 2 round plins and is so arragned that the earth pin of the UK mains plug wioll end up in contact with the earthing spring contact of the German socket. I don't like them much, but I've seen worse. -tony

Yeah, there are aven computer-users who don't own a soldering iron, a mutlimeter or a logic analyser. Kids these days.... I normally carry a couple of known-good mains leads in my toolkit when I do repairs. Alogn with any other 'standard' cables that I suspect I might need. The katter deoebd ib wgat U am working on, if it's an HP machien I'll carry a few HPIBm HPIL and HP-HIL leads, for example Hmm... Not half as annoying as when I get soemthing for repair and the (non-stnadrd) cable is not included with it. I prefer all cables to be included when I get something to repair, if only beceaus the cable could be the cause of the problem. If the machine won't power up at all, I do want to check the mains lead. Ove here, where mains plugs normally contain cartridge fuses, I want to know if the machine is blowing that fuse (if it is, it points to a short-circuit early in the power circuitry). I once had a C64 to repair which only produced mnonochrome output on the Commodore monitor, that was an open-circuit wire in the video cable. -tony

'move right hand one to the right'? I'm sorry, I'll type that again. I normally carry a couple of known-good mains leads in my toolkit when I do repairs. Along with any other 'standard' cables that I suspect I might need. The latter depends on what I am working on, if it's an HP machine -tony

On 28 Nov 2011 at 22:35, Pete Turnbull wrote: I'm sorry--I haven't a clue. Maybe I should ask Samanatha. --Chuck

Tony Duell wrote: :-) We could call you Milligna, the well-known typing errro. -- Pete Peter Turnbull Network Manager University of York

On Nov 30, 2011, at 3:29 PM, Tony Duell wrote: No, but a milliHelen is the power required to launch one ship. - Dave

On 30 Nov 2011, at 20:29, Tony Duell wrote: Incidentally, if anyone needs to know the time I think I've got it written on a piece of paper somewhere. Hold on, I think Major Bloodknock borrowed it ;) -- Mark Benson http://DECtec.info Twitter: @DECtecInfo HECnet: STAR69::MARK Online Resource & Mailing List for DEC Enthusiasts.

That's not a bad idea :-). Although it won't work for me becuase just about al lthe walls here are covered in bookshelves (no, replacing those boosk with e-books is not an option). Yes, that was a second quesito nthat I forgot last night -- identifyign the cables. Some are obvious (a mains plug to IEC 320 socket is going to e wired the normal way, a BNC to RCA phono plug is also obvious [1]. But a DB25 to DB25 could be one of dozens of wirelists [2]. Perhaps I should put a number on each cable and keep a book of the wirelists (and hope I don't loose the book) :-)). [1] FOr ome unknown reason that cable grows legs. They're commonly needed around here to connect compostie monitors to various amchines, and I must have made at least 20 over the years. I can never find one when I need it. [2] Worse 'craqy wirelist' I came across. A VGA (or so) monitor with a DE15 socket on the back for the video input. It was supplied with a cabvel with DE15 plugs on each end. What nobody told me was that the DE15 on the monitor did not have the normal 'VGA' pinout, the cable was cross-connected so the other end would plug into a VGA socket. The only differnce between the 2 ends of the cable was that the isulation between the pins (not the moulded plug hood, but the bit inside the metal shell was black at one end, white at the other. That led me a merry dance... Of course for some cables you may need several at the same time. The obvious oen is mains 'kettle leads', if you want to power up the machine, monitor, disk drive unit, logic analyser, etc. I often need 3 or 4 HPIB cables at th same time too. -tony