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?"

Comments

connector genders

[lingqi]

I was six when i first heard of the term "male" and "female" connectors. Even though I keep pestering my dad about
1) which one is male / female, and
2) why they name it something stupid like that

he just kept "umm... ahhh"-ing and never answered.

I was like 17 when it finally dawned on me why they named it that way. ha! then it all made sense.

moral of the story are:
a) who says electrical engineers / connector designers are not perverted?
b) to save yourself trouble, don't talk about male/femail connectors in front of little kids.

Re:The eternal question...

[BiOFH]

Sorry -- According to the one source no one seemed to bother with (Amphenol themselves) it is, as the coward pointed out, 'Bayonet Neill Concelman' and was named for Carl Concelman (and not Carl & Concelman).

This was an easy find:
http://www.amphenolrf.com/products/bnc.asp

Connectors in my PC

[Waffle Iron]

Hmm... I'll waste some time here and assign grades to the connectors in my PC on a scale of 1 to 10:

• Keyboard/mouse DIN - 5. Works OK, but hard to orient. Making mouse and keyboard identical was stupid. Feel not very satisfying.
• AC Power cord to power supply - 9. Very satisfying feel. Easy to use.
• 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.
• 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).
• USB connector - 9. Sure beats previous solutions. Would be nice if the up/down orientation distinction was more obvious.
• 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.
• 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.
• 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.)
• 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.
• Centronix printer connector - 1. See previous entry. This end is especially bulky and cheap feeling, to boot.
• 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.
• Internal SCSI connection - 3. Same problems as IDE (except for length limitation), plus additional confusion over terminations, ID numbers, and incompatible speeds and widths.
• CD-ROM audio - 6. Not too bad, once you track down where the connection is on the motherboard.
• 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.
• Motherboard power - 7. Doesn't stand out much, no big problems.
• Misc motherboard stake pin connections - 2. No physical alignment constraints and poor silkscreen markings make these a big hassle.
• 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.
• PCI Slots - 6. Relatively unexciting.
• PCMCIA Slots - 8. I'm amazed at how all of those tiny pins connect without getting crushed. Good feel, ejection button is fun.

Re:Connectors in my PC

[Tablizer]

Your forgot one:

• Human sex organs - 7. Nice, but it would be better if the male had it's own female connector slot and double-jointed-ness in the pin for the the times that male can't find an opposing connector.

Re:Power supply adapters and plugs...

[K8Fan]

The UK AC plugs may be large, but they are safe, which is a lot more than I can say for the horrible US AC plug design. I visited the UK last year with a bunch of US multi-voltage video equipment. My British hosts were stunned at how bad the US plug design was, and how easy it would be to shock yourself as you inserted or removed one. The hot blade is exposed with AC power on it - if your finger should slip, you get zapped.

The UK plug design is plastic along the length of the blade, and only the end is metal. By the time you see the metal tip of the blades, the circuit is already broken.

another design center, another solution

[wfmcwalter]

It's interesting to see how the same old problem is solved in a new way when your target user varies from the usual.

I'm always impressed by the connectors for peripherals (generally controllers) on modern video-game consoles. Consider, if you will, the humble playstation connector:

• It can be operated successfully by a two year old, with no training or supervision.
• It's impossible to connect it wrongly.
• It appears to be entirely immune to the harmful environmental contaminants associated with its users (small children and lonely geeks).
• ... and it absolutely, positively will not break.

If only connectors for "grownups" were designed this way.