Slashdot Mirror
Connectors: A History of Their Technology?
dpbsmith asks: "It seems like a simple engineering problem--construct a device for easily and safely connecting several dozen wires at the same time--but the variety and creativity in their design over the years has been amazing, and, clearly there have been trends, fashions, and styles. In the fifties and sixties, virtually all connectors were roughly similar to the D-Sub design used for RS-232. A stiff, straight pin engaged a springy socket that contacted and bore against it on all sides. There were minor variations in shape and placement; the Amphenol Blue Ribbons (think Centronics), the connectors into which circuit boards engaged, but they were all variations on a theme. I was absolutely astounded the first time I saw a modular RJ-11 connector. Cheap, effective, and utterly unlike anything I'd ever seen before. Who invented these? Western Electric? Recently, we have the USB connector and the Firewire connector, obviously members of the same family (and a cheap-and-cheesy-seeming family it seems); on the other hand, my telephone and my digital camera have connectors that are very small and snap in with a positive lock that must be released with a squeeze, obviously yet another fundamentally different design. What do people know about the design, history, and engineering behind connectors over the years? Is it all hidden away, trade secrets of the connector companies, or is their a story that can be told?"
Talking about connectors, one thing that really mades me mad is the amount of power supply adapters we have to have these days. My office floor is littered with them, for net routers, printer, laptops, displays, mobiles etc. etc. Why can't we have two circuits? And for that matter, why are electric plugs so big. In the UK the are enormous. Many things these days only take a tiny bit of power - can't we have smaller electrical plugs? On my travels it seems that in the rest of the world electrical plugs are pretty big too. Is there anywhere with little dainty ones and without huge power adapters? Japan perhaps?
I'm always impressed by the connectors for peripherals (generally controllers) on modern video-game consoles. Consider, if you will, the humble playstation connector:
If only connectors for "grownups" were designed this way.
## W.Finlay McWalter ## http://www.mcwalter.org ##
And male panel connectors are called jacks, too.
Male/Female refers to the contact type.
Plug/Jack refers to movable/fixed. The more movable connector (eg, on the end of a cable) is a plug, and the less movable connector (eg, on a panel) is a jack. This is covered in the ANSI standard for reference designators.
Can anyone think of a crappier design than SCART??!
* Keyboard/mouse DIN - 5. Works OK, but hard to orient. Making mouse and keyboard identical was stupid. Feel not very satisfying.
;).
:)
Evolution at work, the tranition from DIN to minidin occured at the same time as the transition away from serial mice.
* AC Power cord to power supply - 9. Very satisfying feel. Easy to use.
Ah, yes, the trusty IEC connector. AKA kettleleads in the UK. Great things, pity the distribution boards are so expensive.
* AC Power cord to wall outlet - 6. A true classic. Rated down because of childhood memories of annoying transition to 3-prong grounded outlets. Could have used better protection against fingers/children.
I'd not give US wall plugs more than a 3. At least they have flat connectors, unlike those crappy EU ones. Unsheathed, tinny wobbly little things. UK three-pin plugs are far better.
* 1/8-inch audo jacks - 8. Easy to use. It would be better if all audio equipment would use the same connector (i.e., no 1/4-inch or RCA jacks).
Not robust enough, I've wrecked a couple of these.
* USB connector - 9. Sure beats previous solutions. Would be nice if the up/down orientation distinction was more obvious.
OK. I guess.
* RJ-11/RJ-45 modem/network - 8. Very convenient; elegant design. Achilles heel: if you try to pull the cable out of a tangle of wires, you're likely to break the little retaining tab and ruin the cable.
Agreed
* 15-pin VGA video - 5. Hard to orient, screws are inconvenient (but easier than the 3-BNC connector alternative). Technical achievement award to those who figured out how to kludge 1600x1200 signal frequencies through this thing.
Should see old SUN equipment, the connector contains little coax connectors.
* 9-pin serial connector - 3. Boring. Same problems as VGA. Should have been done with 2 or 3 pins. (Old larger serial connectors rate a 1 for total overkill.)
Most of the extra pins have a use. Flow control for a start. Important when you're going to throughput with as little silicon as possible.
* Parallel printer connector - 1. Choosing to save money by not putting a shift register in the printer was one of the most unfortunate decisions in the history of personal computing. How many kilotons of copper have been needlessly wasted on all those wires? Cable is thick, heavy and expensive. This is a classic example of how the marketplace can converge on a suboptimal solution and then get locked in.
Greater throughput than other tech at the time. Similar connections were used for scsi.
* Centronix printer connector - 1. See previous entry. This end is especially bulky and cheap feeling, to boot.
The good thing about these is that they're rated for about 50V. If you have a lot of relays to control these things are ideal, and commonplace.
* Internal IDE connection - 3. Ribbon cable is hard to manage. Master/slave business is a hassle. Doesn't seem to be a clear standard on orientation keying. Hard to tell when properly seated. Max length too short.
Designed to a price.
* Internal SCSI connection - 3. Same problems as IDE (except for length limitation), plus additional confusion over terminations, ID numbers, and incompatible speeds and widths.
More modern internal SCSI should have D-shaped connectors, nicer.
* CD-ROM audio - 6. Not too bad, once you track down where the connection is on the motherboard.
The latch is a mixed blessing, good in that you don't knock it out, bad in that it's really hard to release when it's clustered up with the rest of the junk on a mobo.
* Hard drive power. - 9. Surprisingly easy to use, given the amperage it must support. The twisting behavior is really nice. I've never had problems with these.
MOLEX. I've had these fall apart on cheap PSUs.
* Motherboard power - 7. Doesn't stand out much, no big problems.
No problems, as long as you're using standard equipment. Some large manufacturers pull tricks like swapping positions of different power levels. A multimeter helps.
* Misc motherboard stake pin connections - 2. No physical alignment constraints and poor silkscreen markings make these a big hassle.
Cheapness rules here
* ISA Slots - 3. The lack of a proper mechanical specification for these caused a lot of alignment headaches. It's a good thing you could use the slot screw to get the thing all the way in with brute force. Things got better once most cards shrunk to the size of a business card; less to go wrong.
Yet another near-dead connector. Lasted well considering. I've had more problems seating PCI cards with their smaller connectors.
* PCI Slots - 6. Relatively unexciting.
Ayup. You missed AGP. I'm amazed how densely that bastard is packed
* PCMCIA Slots - 8. I'm amazed at how all of those tiny pins connect without getting crushed. Good feel, ejection button is fun.
Not much finer than an IDE connector, and a better alignment system.
Missing:
slot1 (pretty good, but obviously a dead end) 7,
Socket7, 8, A, 370 etc etc. some great fun with no alignement, socket 8 worthy mention for being two different pin densities in the same connector. 3-9
Firewire: good design, 10
Floppy power: what internal power supply should be
BNC.. great for signals
Triax, for studio and location video feed: FAR TOO PICKY 2
FC and other fibre connectors, incredible, they do near instantly what takes me by hand about 5min.
-Yarn - Rio Karma: Excellent
Amazing. I had been told by many people that this was a British Naval Connector. I was once asked this as a trivia question, answered 'British Naval Connector' and was told I was correct!
/var and /usr. No one seems to agree. It's very new technology but the truth may already have been lost.
Goes to show you how incorrect info can become official if no one checks. Kind of like the origins of the names of files and directories in Unix, like
=rmortyh
RJ stands for Registered Jack (check out the glossary at the end of this FCC document).
BNC stands for Bayonet Neill Concelman