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Barrel connectors

Ah, OK.

I've seen numerous colors: yellow, red, ubiquitous_black, etc. At first, I was excited thinking there might be some color code that would make sorting out what's what easier. But, that didn't pan out.

So, a micrometer and selection of drill bits are my only real way of figuring out what the characteristics of a particular connector are.

Great tolerance there! :>

I am more interested in understanding how/why particular sizes are chosen as there doesn't seem to be any sense to it all.

It *seems* US firms have the barrel negative wrt center post. And, many far east firms the opposite.

Except when they aren't! :<

Yes, but the connectors are more fragile and harder to mate.

I've had to replace a number of jacks -- laptops, organs/"keyboards", etc. Usually devices that ither see lots of motion while in use

*or* have heavy cords dangling off the connection, unsupported. I've also encountered broken "wipers" in the jack (the contact that mates with the O.D.)

I figured connectors with a *longer* and *wider* barrel might be more mechanically secure -- not just because of the increased size but, also, because they could be more readily "supported" by bits of the device into which they mate (even if that support is non-conductive)

I've also seen connectors that have quarter-turn locks built in. Insert and rotate to keep it from falling out (or being PULLED out)

I think the biggest risk, there, is a "plug" with a "too large" I.D. being *apparently* mated to one with the correct O.D. but smaller I.D. -- not a very robust connection (if at all!)

Exactly my thoughts (electrically). Let it feed anoher (set of) converters inside the device. More assurance that you have *all* the right supplies instead of HOPING to have the *one* right input supply.

Ah, hadn't thought of that! Hadn't *planned* on such a connector, though. Worth remembering for future encounters!

Yes. Looks sort of like the *mate* to the "original style" (hence my reason to call it "inverse")

Ahhhhh! Yes, that makes perfect sense! I'd simply assumed the outside of the barrel was one conductor (like it had been for the "original" plugs) and the pin was there just to "be different". The larger diameter and length that typically are associated with these being mechanical "enhancements" -- e.g., laptops see a fair bit of motion reflected to that connection!

OK. Allows the PS to be "identified" by the device using it. Presumably, could also ensure the supply isn't powered up if t is "wrong"!

Could also be used to power *down* the power supply when the device doesn't need it any longer!

Or, could just be there to sell "special powersupplies" :-(

Ah, OK. Clever. So, charge time depends on power supply and not something inherent in the device! Yes, that makes perfect sense!

And, of course, the truth is probably somewhere in between.

Thanks! That makes things a lot clearer! I will have to get a bright light and loupe and peer *in* the end of the plug. There should be a conductive surface there in addition to the pin.

(and, *probing* would obviously be something done with care lest "something" get shorted to the pin!)

Reply to
Don Y
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Isn't that CARP? :>

Yeah but most of the issues I've seen have been mechanical related. Hence "CRAP".

Often lots of fatigue just past the strain relief. But, I have seen the device into which the cable plugs also experience failures -- "jacks" snapping off or developing intermittents as they lose their adhesion to the solder pads. Very annoying on laptops (as they are often a PITA to disassemble without breaking ots of little plastic things!)

Yes, I realized that from Matt's post just now. Thanks. Previously, anything with more than 2 contacts had been obvious in a plastic molded plug. IBM & Dell made several laptops like this. I'd always assumed the extra pin was another supply -- much like it is on many external (USB) disk enclosures. I will have to make a point of gutting one next time I come across a "spare".

Reply to
Don Y

"Don Y"

** The most annoying and expensive ( for owners) to fix falure is when sockets develop cracked joints on the PCB. Single sided boards are the main culprits, as there is so little strength in the copper foil to resist movement.

Some makers try to wedge socket inlets into a hole in the case - that helps a bit.

But far better is to use sockets that fasten to the case with a nut OR a pair of bolts to the case or PCB.

If I see a keyboard instrument with a broken DC inlet - I usually fit a whole new connector that fastens to the case.

2 or 4 pins "CB mic" connectors with locking rings are ideal

.... Phil

Reply to
Phil Allison

If you're not happy with the price, have a look at Lemo .

--

-T.
Reply to
Tauno Voipio

On second thought, you and Sloman really ought to get to know one another better.

--

John Larkin                  Highland Technology Inc 
www.highlandtechnology.com   jlarkin at highlandtechnology dot com    

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom timing and laser controllers 
Photonics and fiberoptic TTL data links 
VME  analog, thermocouple, LVDT, synchro, tachometer 
Multichannel arbitrary waveform generators
Reply to
John Larkin

Doesn't this connector seem confused about its gender?

Joe Gwinn

Reply to
Joe Gwinn

Phil you seem to be free of all medication at this point and now have demons running around in your mind. It doesn't seem like it is working well. Please use some new abusive terms for me, your same old line is, well, get old. Thanks, Mike

Reply to
amdx

That's just being politically correct.

Reply to
amdx

Autism is a birth defect. Why abuse people for a problem that they didn't cause?

Many tekkies are, to some degree, asperger-y. So what?

Phil seems to have Tourettes. Probably another birth defect.

--

John Larkin                  Highland Technology Inc 
www.highlandtechnology.com   jlarkin at highlandtechnology dot com    

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom timing and laser controllers 
Photonics and fiberoptic TTL data links 
VME  analog, thermocouple, LVDT, synchro, tachometer 
Multichannel arbitrary waveform generators
Reply to
John Larkin

OK, I can tell you're USAian. Now all we have to do is get Phil to say it, 'ay?

Reply to
krw

Rat Shock color-codes their replacement connectors, but hardly anybody else does.

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

This is the relevant part here.

The reasons probably include:

People's Shining Power Supply Factory #7 had a blowout sale on adapters with a certain size plug. (For 5 cents extra, PSPSF7 will download the UL or TUeV artwork from the net and print that on there, too!)

The previous product had that size, and there are still lots of adapters in stock.

The previous product had a different size, but greater sales of replacement power supplies are now desired.

The competition uses that size and they wanted to be plug-compatible.

The competition uses a different size and they wanted to be plug- incompatible.

The device has some other hole that should not have a power supply connected to it, so the power supply is chosen to not fit the wrong hole.

Marketing wanted the device to be 0.5 mm thinner, so the first power supply plug wouldn't fit.

Dumping 100 watts through the previous, smaller, plug didn't work, so they picked a bigger one with more contact area.

I've noticed that too. I sort of like tip-positive, if for no other reason that the barrel part is more exposed, and I'd rather have that be ground. In a house it doesn't matter so much, as DC ground should be isolated from AC ground, but in a car, DC ground is everywhere... it's nice if a cigarette-lighter cord doesn't blow its fuse when the plug end flops against the seat track or something.

Yeah, I've had that happen before. It depends on how much travel and tension the spring in the ID of the connector has.

Some other notes on barrel connectors:

You can get adapters from both male and female barrels to screw terminals, which is handy for prototyping. Mouser JACK21-F-TERM and JACK21-M-TERM; Sparkfun

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and
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; All Electronics
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and
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.

You can get adapters from one size to another:

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You can get "extension cords" and cables with barrel connectors on one end:

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Standard disclaimers apply: I don't get money or other consideration from any companies mentioned.

Matt Roberds

Reply to
mroberds

Dat's roite, mayte.

--

John Larkin                  Highland Technology Inc 
www.highlandtechnology.com   jlarkin at highlandtechnology dot com    

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom timing and laser controllers 
Photonics and fiberoptic TTL data links 
VME  analog, thermocouple, LVDT, synchro, tachometer 
Multichannel arbitrary waveform generators
Reply to
John Larkin

So, it's only helpful if you are replacing one RS product with another?

Or, none of the above. Someone just *picked* a size and let someone else chase down the actual adapter, etc.

I repair/rescue lots of kit (from lots of places -- not uncommon to see something with a european power plug, etc.). So, a big part of the "project" is often sorting out what the hell you need to *provide* (power) to the device -- before you can even see if it is working! (wall warts and bricks tend to get misplaced or separated fromtheir "mates")

Early on, the solution I came up with was to unceremoniously *cut* the plugs off a variety of "power supplies" (which were headed for the tip) and wire them to a digitally programmable PS. So, when I have a bit of kit that *might* be worth rescuing, I can hunt down the power requirements (USUALLY written SOMEWHERE on the device *or* a WWW search -- or, GUESS!), type in V & I and then hunt for which of the multiple "ends" of my homegrown octopus cable happen to fit the device. If the results look promising,

*then* worry about finding/making a real PS to marry to it!

Ah, that might be nice to have on hand (one of each size). Currently, I keep "common" plug sizes on hand so I can butcher PS's that have the right V/I but wrong connector!

Hmmm... that sounds like it might be "iffy". The connectors seem pretty crappy to begin with and that just adds aother "wiggle" to the equation.

Someone made a device (laptop?) in which the cord *to* the device (from the PS) ws replaceable. Either it was done to allow a single PS to be used with multiple devices *or* anticipated the cord failing (from use). Hard to imagine adding the second connector without a *good* reason!

I notice all the "house numbers" are of the form MRI#### [Matt Roberds Industries? :>]

Thanks for the references and the effort you went thru! Take a few bucks out of petty cash... ;-)

Reply to
Don Y

Yes quite, never heard it used as a term of abuse before hanging out here. I don't know much about Autism, but it is ironic that those who throw that "insult" around are *precisely* those who appear, shall we say, a bit socially challenged.

Hmm, does Tourettes still work with the written word?

--

John Devereux
Reply to
John Devereux

I prefer to delegate.

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Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 USA 
+1 845 480 2058 

hobbs at electrooptical dot net 
http://electrooptical.net
Reply to
Phil Hobbs

"amdx"

( snip more s**te )

** Fuck off - you PATHETIC damn troll
Reply to
Phil Allison

"John Devereux"

** Nonsense.

It is a mental disability typically accompanied by narcissism and sociopathy.

** It's not abuse to point out what someone IS.

... Phil

Reply to
Phil Allison

on 17/11/2013, Don Y supposed :

Try this for adapters.

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--
John G
Reply to
John G

Except on laptops that use magnetic locking connectors.

True. However, replacement power supplies are fairly cheap on eBay. In other words, lousy quality is acceptable if the replacement is available and cheap.

Buy the cheapest. By the time the customer realizes that it's junk, you and the customers money are gone.

Of course. Everything can fail in some way. With laptops, it's mechanical stress. I repair LOTS of broken power receptacle on laptops. Some examples of design defects.

Right angle connector versus straight-in connector. The right angle has the advantage of surviving having the laptop shoved against a wall or back of desk. This will bend a straight-in connector, place considerable torque onto the receptacle, and sometime break the wire inside the plug. If the wire doesn't break, the flexy and foamy insulation will cold flow and eventually short the power wires.

This particular connector is a problem. It's always supplied with a straight in cable. If this laptop power connection is shoved against a wall, and if the receptacle doesn't break first, the tiny "sense" wire in the connector will break. The result is an adapter that will operate the laptop, but not charge. Of course, the connector is not available individually, so the entire power supply has to be replaced.

The right angle versions of many power connectors are fairly good at relieving some forms of connector stress, but not all of them. It is still possible to destroy the receptacle by pulling on the power cord. Maximum damage is assured by the fairly long plug length, providing maximum leverage and torque.

The right angle design also can destroy the plug if the right angle plug is "spun" while inserted. The yellow plastic used in the connector is fairly soft, and will wear down, forming a funnel entry and a intermittent connection. I've seen a few of these and couldn't determine the culprit until I sawed on connector apart with a Dremel tool.

Meanwhile, there are also changes happening in the design of the power receptacle. Gone are the extra switch contacts in the receptacle, where the slightest mechanical damage will cause them to fail. Gone are the fortified metal retaining clips, that cause the PCB to break instead of the connector. Gone are the PCB mounted receptacles, to be replaced by a pigtail cable assembly. Should the receptacle be mangled during normal operation, it can (somewhat) easily be replaced without soldering. Unfortunately, I still have to tear apart the laptop and remove the motherboard just to get to the (somewhat) easily replaceable pigtail connector. Since there's now only the plastic cast holding the connector in place, the flimsy plastic case parts are usually also mangled. I predict that eventually the designers will get the clue, and design a sacrificial power connector, that can be easily and cheaply replaced.

They are more difficult to forcefully insert into the wrong receptacle and blow up the laptop, power supply, or both. Having a common form factor, with minor variations in size, made it possible to easily destroy things with a minimum of force. With the reverse mechanically polarized design, that's more difficult with normal receptacles, but will eventually cause the same problems when they are universally available in minor variations in size. I guess we'll have to abandon round connectors once all the various polarity, pin, and barrel sizes are exhausted, and switch to square or other odd shaped power connectors.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558
Reply to
Jeff Liebermann

One design flaw with some Dells is that their fat coaxial power connector are in back, and right beside the RJ-45 Ethernet jack. The Ethernet jack has low quality spring materials, so it gets bent out of shape and will no longer work reliably if the power connector is accidentally shoved into it.

Best regards, Spehro Pefhany

--
"it's the network..."                          "The Journey is the reward" 
speff@interlog.com             Info for manufacturers: http://www.trexon.com 
Embedded software/hardware/analog  Info for designers:  http://www.speff.com
Reply to
Spehro Pefhany

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