Forums

Barrel connectors

Started by Don Y November 15, 2013
On 11/16/2013 12:19 PM, krw@attt.bizz wrote:
> On Sat, 16 Nov 2013 09:12:26 -0800, John Larkin > <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote: > >> On Sat, 16 Nov 2013 11:28:33 -0500, krw@attt.bizz wrote: >> >>> On Fri, 15 Nov 2013 21:49:52 -0500, Phil Hobbs >>> <pcdhSpamMeSenseless@electrooptical.net> wrote: > <...> > >>>> >>>> Well, you seem to think that I'm an American, based on your poorly-aimed >>>> insults. Guess again. >>> >>> I'm amazed to see you as the target of Phyllis' psychotic rage. >> >> The way to tell a Canadian from a USian is to get them to say "about." > > OK, I can tell you're USAian. Now all we have to do is get Phil to > say it, 'ay? >
I prefer to delegate. http://www.youtube.com/watch?v=sEbUtpPQihM 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
"amdx"

( snip more shite )

** Fuck off   -  you PATHETIC damn troll




"John Devereux"
> >> Autism is a birth defect.
** Nonsense. It is a mental disability typically accompanied by narcissism and sociopathy.
> Yes quite, never heard it used as a term of abuse
** It's not abuse to point out what someone IS. ... Phil
on 17/11/2013, Don Y supposed :
> Hi Matt, > > On 11/16/2013 11:26 AM, mroberds@att.net wrote: >> Don Y<This.is@not.me> wrote: >>> 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. >> >> Rat Shock color-codes their replacement connectors, but hardly anybody >> else does. > > So, it's only helpful if you are replacing one RS product > with another? > >>> I am more interested in understanding how/why particular sizes >>> are chosen as there doesn't seem to be any sense to it all. >> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ >> >> 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. > > Or, none of the above. Someone just *picked* a size and let > someone else chase down the actual adapter, etc. > >>> It *seems* US firms have the barrel negative wrt center post. >>> And, many far east firms the opposite. >>> >>> Except when they aren't! :< >> >> 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. > > 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! > >>> 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!) >> >> 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 https://www.sparkfun.com/products/10287 >> and https://www.sparkfun.com/products/10288 ; All Electronics >> http://www.allelectronics.com/make-a-store/item/SDP-S/RETRO-FIT-2.1MM-COAX-SOCKET/1.html >> and >> http://www.allelectronics.com/make-a-store/item/SDP-P/RETRO-FIT-2.1MM-COAX-PLUG/1.html > > 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! > >> You can get adapters from one size to another: >> http://www.digikey.com/product-detail/en/6872340FG/271-2628-ND >> http://www.allelectronics.com/make-a-store/category/198300/Connectors-DC-Power-Coax/Adapters/1.html > > 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. > >> You can get "extension cords" and cables with barrel connectors on one >> end: >> http://www.allelectronics.com/make-a-store/category/123/Cables-Co-Ax-Power-Plugs/1.html > > 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! > >> Standard disclaimers apply: I don't get money or other consideration >> from any companies mentioned. > > <grin> 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... ;-)
Try this for adapters. https://www.google.com.au/search?q=octopus+cable&ie=utf-8&oe=utf-8&rls=org.mozilla:en-US:official&client=firefox-a&gfe_rd=ctrl&ei=-wCIUsz4BKWN8Qf2qYGQBg&gws_rd=cr -- John G
On Fri, 15 Nov 2013 00:47:10 -0700, Don Y <This.is@not.Me> wrote:

>They're everywhere!
Except on laptops that use magnetic locking connectors. <http://en.wikipedia.org/wiki/MagSafe>
>And, often CRAP!
True. However, replacement power supplies are fairly cheap on eBay. In other words, lousy quality is acceptable if the replacement is available and cheap.
>Any guidelines on selection criteria?
Buy the cheapest. By the time the customer realizes that it's junk, you and the customers money are gone.
> Any worries about failure modes?
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. <http://www.laptoprepair101.com/laptop/2008/07/17/laptop-battery-stops-charging-when-move-power-cord/> This particular connector is a problem. <http://bixnet.net/images/Connector-D003.jpg> 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.
>Do the "inverse" variety (now popular on laptops, LCD's, etc.) offer >any special advantages over the traditional style?
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
On Sat, 16 Nov 2013 16:46:04 -0800, the renowned Jeff Liebermann
<jeffl@cruzio.com> wrote:

> 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.
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
Hi John,

On 11/16/2013 4:36 PM, John G wrote:

> Try this for adapters. >
[snipped long URL due to line length limitations] I have several "universal" bricks/wall warts with different approaches to "voltage configuration" and "plug configuration". But, they tend to be in different power/size categories. E.g., the little guys in the "few watt, lower voltage" range vs. the larger ones intended more for folks who have lost their laptop power supply. Sometimes, a voltage selector switch and a "dumb" removable "plug". Other times, a "smart plug" that selects the voltage for you ("Use the A plug for these laptop models; the B plug for these other models; the C...") The programmable lab supply is just easier. Type in a voltage. Type in a current limit. Then stand back and see if the "device" does anything (other than get warm). So, if I am testing an LCD monitor, gaming device, laptop or electronic organ, it's all the same...
Hi Jeff,

On 11/16/2013 5:46 PM, Jeff Liebermann wrote:
> On Fri, 15 Nov 2013 00:47:10 -0700, Don Y<This.is@not.Me> wrote:
>> And, often CRAP! > > True. However, replacement power supplies are fairly cheap on eBay. > In other words, lousy quality is acceptable if the replacement is > available and cheap.
I think its more fundamental than that! Laptops are typically considered disposable. So, serviceability and longevity don't enter into the design equation -- just price! I absolutlety *hate* it when I encounter a really *nice* laptop with a problem. Because it puts pressure (self-inflicted) on me to *fix* it instead of scrapping it! Then begins the stressful task of trying to get it apart without breaking anything or doing any cosmetic damage. :< ToughBooks are reasonably "easy" to work on -- as long as you don't drop any screws! OTOH, one of *my* laptops has a flakey keyboard and I just keep tolerating it rather than deal with replacing it (and keyboards tend to be *easy* fixes!). I guess I am hoping I decide to discard it before that day comes :>
>> Any guidelines on selection criteria? > > Buy the cheapest. By the time the customer realizes that it's junk, > you and the customers money are gone.
Sorry, I mean picking a connector for durability, etc. I can't believe there is much money to be save in the *connector* choice!
>> Any worries about failure modes? > > 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.
Straight in can also be an issue on *side* entry. Set something down on/near it and you put a lot of vertical stress on it.
> 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.
I think that was part of what the "twist lock" connectors I mentioned were designed to minimize (as well as preventing their accidental removal) Ideally, an "air core" transformer design so there is no connector and no "hole" for materials to enter the device (liquids). But, that tends to put you in a lower power category.
Hi Spehro,

On 11/16/2013 6:10 PM, Spehro Pefhany wrote:
> On Sat, 16 Nov 2013 16:46:04 -0800, the renowned Jeff Liebermann > <jeffl@cruzio.com> wrote: > >> 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. > > 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.
I've seen similar damage as the "modem" connector is often adjacent to the "network" connector. As many folks (?) do things by feel, if you end up with the plug in the wrong connector, it *will* fit but will typically mangle the fingers on entry/withdrawal.
Don Y used his keyboard to write :
> Hi John, > > On 11/16/2013 4:36 PM, John G wrote: > >> Try this for adapters. >> > > [snipped long URL due to line length limitations]
http://tinyurl.com/pjrwtbl
> I have several "universal" bricks/wall warts with different > approaches to "voltage configuration" and "plug configuration". > But, they tend to be in different power/size categories. > > E.g., the little guys in the "few watt, lower voltage" range > vs. the larger ones intended more for folks who have lost > their laptop power supply. > > Sometimes, a voltage selector switch and a "dumb" removable > "plug". Other times, a "smart plug" that selects the voltage > for you ("Use the A plug for these laptop models; the B plug > for these other models; the C...") > > The programmable lab supply is just easier. Type in a voltage. > Type in a current limit. Then stand back and see if the "device" > does anything (other than get warm). > > So, if I am testing an LCD monitor, gaming device, laptop > or electronic organ, it's all the same...
http://tinyurl.com/pjrwtbl -- John G