Forums

Wall Wart Woes!

Started by Martin Brown February 20, 2012
I wonder how many of us have old modems/WiFis/Routers salted away in a 
dark cupboard waiting for the day when they might be needed again for 
something? (usually helping a charity with their IT needs)

The main annoyance is that the wall warts and even laptop PC supplies of 
old span a crazy range of random voltages and both polarities. And  the 
PSU often dies or simply gets lost leaving the unit orphaned.

That isn't too much of a problem since modern switched mode supplies and 
fit anything connectors are easy enough to come by. The really annoying 
thing in recycling kit for a charity where the original PSU is lost is 
that in most cases neither the manual nor the unit itself states whether 
the power connector is positive or negative centre  pin. The lost PSU of 
course displays which voltage, current and polarity it outputs but the 
unit requiring power very often does not.

Now you could take it apart, but more often just play Russian roulette 
and see if the LEDs light. Why can't manufacturers label the connector 
with (+)- or (-)+ nnV/mmA? I am fed up with just seeing "POWER".

That label tells me nothing I can't already guess from the type of 
connector - what I really want to know is what voltage and polarity!

Does anyone else find this annoying?

-- 
Regards,
Martin Brown
"Martin Brown" <|||newspam|||@nezumi.demon.co.uk> wrote in message 
news:5tn0r.7197$I%6.6649@newsfe16.iad...
>I wonder how many of us have old modems/WiFis/Routers salted away in a dark >cupboard waiting for the day when they might be needed again for something? >(usually helping a charity with their IT needs) > > The main annoyance is that the wall warts and even laptop PC supplies of > old span a crazy range of random voltages and both polarities. And the > PSU often dies or simply gets lost leaving the unit orphaned. > > That isn't too much of a problem since modern switched mode supplies and > fit anything connectors are easy enough to come by. The really annoying > thing in recycling kit for a charity where the original PSU is lost is > that in most cases neither the manual nor the unit itself states whether > the power connector is positive or negative centre pin. The lost PSU of > course displays which voltage, current and polarity it outputs but the > unit requiring power very often does not. > > Now you could take it apart, but more often just play Russian roulette and > see if the LEDs light. Why can't manufacturers label the connector with > (+)- or (-)+ nnV/mmA? I am fed up with just seeing "POWER". > > That label tells me nothing I can't already guess from the type of > connector - what I really want to know is what voltage and polarity! > > Does anyone else find this annoying? > > -- > Regards, > Martin Brown
Yep - I took a punt once with a cordless phone and let the smoke out. Now I pull alpart and check to be sure!
On 2/20/2012 3:26 AM, Martin Brown wrote:
> I wonder how many of us have old modems/WiFis/Routers salted away in a > dark cupboard waiting for the day when they might be needed again for > something? (usually helping a charity with their IT needs) > > The main annoyance is that the wall warts and even laptop PC supplies of > old span a crazy range of random voltages and both polarities. And the > PSU often dies or simply gets lost leaving the unit orphaned. > > That isn't too much of a problem since modern switched mode supplies and > fit anything connectors are easy enough to come by. The really annoying > thing in recycling kit for a charity where the original PSU is lost is > that in most cases neither the manual nor the unit itself states whether > the power connector is positive or negative centre pin. The lost PSU of > course displays which voltage, current and polarity it outputs but the > unit requiring power very often does not. > > Now you could take it apart, but more often just play Russian roulette > and see if the LEDs light. Why can't manufacturers label the connector > with (+)- or (-)+ nnV/mmA? I am fed up with just seeing "POWER". > > That label tells me nothing I can't already guess from the type of > connector - what I really want to know is what voltage and polarity! > > Does anyone else find this annoying? >
I know this is high level rocket science, but... 1. The label on the unit tells the voltage. Always. 2. The polarity can be determined with a visual inspection of the board at the connector, they will have at least one filter capacitor, with a marked plus lead. -- I'm never going to grow up.
On Mon, 20 Feb 2012 07:49:59 -0500, PeterD <peter2@hipson.net> wrote:

>I know this is high level rocket science, but... > >1. The label on the unit tells the voltage. Always. > >2. The polarity can be determined with a visual inspection of the board >at the connector, they will have at least one filter capacitor, with a >marked plus lead. >
The polarity of the connector is also almost always on the AC powered product ID label as well. OR it can be ID'd from the cord feeding the plug sometimes too. The 'icon' on the device being powered sometimes shows the polarity 'desired' by it as well. Look closely at the logo at the power pin, if there is one. The standard is typically "center positive" because the connector design is usually such that the barrel (outer) connects first. Or for whatever reason, it has been pretty much the de-facto method. There are, however "center negative" versions as well. So much for adopting and maintaining standards. Maybe we should ring the necks of all the dopes who stubbornly did it "their way" anyway. I have also used in a design, types which have a threaded ferrule on them and actually attach to the device the get plugged into. I would want that exposed ferrule to be chassis, which is usually negative.
On Mon, 20 Feb 2012 08:26:40 +0000, Martin Brown
<|||newspam|||@nezumi.demon.co.uk> wrote:

>I wonder how many of us have old modems/WiFis/Routers salted away in a >dark cupboard waiting for the day when they might be needed again for >something? (usually helping a charity with their IT needs) > >The main annoyance is that the wall warts and even laptop PC supplies of >old span a crazy range of random voltages and both polarities. And the >PSU often dies or simply gets lost leaving the unit orphaned. > >That isn't too much of a problem since modern switched mode supplies and >fit anything connectors are easy enough to come by. The really annoying >thing in recycling kit for a charity where the original PSU is lost is >that in most cases neither the manual nor the unit itself states whether >the power connector is positive or negative centre pin. The lost PSU of >course displays which voltage, current and polarity it outputs but the >unit requiring power very often does not. > >Now you could take it apart, but more often just play Russian roulette >and see if the LEDs light. Why can't manufacturers label the connector >with (+)- or (-)+ nnV/mmA? I am fed up with just seeing "POWER". > >That label tells me nothing I can't already guess from the type of >connector - what I really want to know is what voltage and polarity! > >Does anyone else find this annoying?
If you but a model K901 Ethernet switch, why doesn't the wart have a label "For model K901" ?
Hi Martin,

On 2/20/2012 1:26 AM, Martin Brown wrote:
> I wonder how many of us have old modems/WiFis/Routers salted away in a > dark cupboard waiting for the day when they might be needed again for > something? (usually helping a charity with their IT needs) > > The main annoyance is that the wall warts and even laptop PC supplies of > old span a crazy range of random voltages and both polarities. And the > PSU often dies or simply gets lost leaving the unit orphaned. > > That isn't too much of a problem since modern switched mode supplies and > fit anything connectors are easy enough to come by. The really annoying > thing in recycling kit for a charity where the original PSU is lost is > that in most cases neither the manual nor the unit itself states whether > the power connector is positive or negative centre pin. The lost PSU of > course displays which voltage, current and polarity it outputs but the > unit requiring power very often does not.
I volunteer at a non-profit that actually *receives* such kit for recycling. If you think its bad trying to chase down *your* wall wart for *your* piece of kit, imagine the problem when donors drop off random bits of kit with the wall warts in a knotted tangle -- which often doesn't include *the* wall wart for the item of interest! (We have, literally, garbage *cans* full of wall warts whose mates are unknown) Some vendors will mark the product with the voltage and polarity of the expected power source. Then, it's "just" a matter of finding the appropriate barrel diameter and center post diameter to "fit".
> Now you could take it apart, but more often just play Russian roulette > and see if the LEDs light. Why can't manufacturers label the connector > with (+)- or (-)+ nnV/mmA? I am fed up with just seeing "POWER".
One gripe *I* have is that the standard scheme for indicating polarity doesn't fare well as it is scaled. Something like: + ----* )---- - where the ")" signifying the barrel contact actually wraps around the "*" signifying the center post. Ink bleed at small scales often turns this into a guessing game: "is that a '-' or a '+'? Is the line from that +/- symbol going to the center *pin*? Or, the enclosing curve??" Why not a simple circle with a sign inside? Takes LESS space on the label (so it could be printed at a larger scale) and removes some of the ambiguity! Or, design devices that are tolerant of polarity reversals! (ideally, *functioning* with either polarity or at least not giving up the ghost with "reversed" polarity!) For my own, personal items, I label each wall wart with the name of its mate and write the power requirements on the mate with a "Sharpie" using the "circled sign" graphic I described accompanied by voltage and amperage. I have a *white* pen for those items that have black cases.
> That label tells me nothing I can't already guess from the type of > connector - what I really want to know is what voltage and polarity!
A vendor once made the observation that center positive is common for US market while many other markets have center negative. I suspect that is *not* universally true (as I have encountered lots of kit with center negative).
> Does anyone else find this annoying?
Let's see... how many souls currently on the planet?
WoolyBully wrote:
> On Mon, 20 Feb 2012 07:49:59 -0500, PeterD <peter2@hipson.net> > wrote: > >> I know this is high level rocket science, but... >> >> 1. The label on the unit tells the voltage. Always. >> >> 2. The polarity can be determined with a visual inspection of >> the >> board at the connector, they will have at least one filter >> capacitor, with a marked plus lead. >> > The polarity of the connector is also almost always on the AC > powered > product ID label as well. OR it can be ID'd from the cord > feeding the > plug sometimes too. The 'icon' on the device being powered > sometimes > shows the polarity 'desired' by it as well. Look closely at > the logo > at the power pin, if there is one. > > The standard is typically "center positive" because the > connector > design is usually such that the barrel (outer) connects first. > Or for > whatever reason, it has been pretty much the de-facto method. > > There are, however "center negative" versions as well. So much > for > adopting and maintaining standards. Maybe we should ring the > necks of > all the dopes who stubbornly did it "their way" anyway. > > I have also used in a design, types which have a threaded > ferrule on > them and actually attach to the device the get plugged into. I > would > want that exposed ferrule to be chassis, which is usually > negative.
I've just had a look at the two wallwart-powered ADSL modems on my desk, and though they both specify the required DC supply voltages, neither one shows the polarity. They are neither moulded nor printed anywhere. A high majority of the devices I've worked with and on over the years use the outer ring as the positive contact, with the opposite polarization being occasional exceptions. I've always considered the more common practice illogical.
Don Y wrote:
> > Hi Martin, > > On 2/20/2012 1:26 AM, Martin Brown wrote: > > I wonder how many of us have old modems/WiFis/Routers salted away in a > > dark cupboard waiting for the day when they might be needed again for > > something? (usually helping a charity with their IT needs) > > > > The main annoyance is that the wall warts and even laptop PC supplies of > > old span a crazy range of random voltages and both polarities. And the > > PSU often dies or simply gets lost leaving the unit orphaned. > > > > That isn't too much of a problem since modern switched mode supplies and > > fit anything connectors are easy enough to come by. The really annoying > > thing in recycling kit for a charity where the original PSU is lost is > > that in most cases neither the manual nor the unit itself states whether > > the power connector is positive or negative centre pin. The lost PSU of > > course displays which voltage, current and polarity it outputs but the > > unit requiring power very often does not. > > I volunteer at a non-profit that actually *receives* such kit for > recycling. If you think its bad trying to chase down *your* wall wart > for *your* piece of kit, imagine the problem when donors drop off > random bits of kit with the wall warts in a knotted tangle -- which > often doesn't include *the* wall wart for the item of interest! > > (We have, literally, garbage *cans* full of wall warts whose mates > are unknown) > > Some vendors will mark the product with the voltage and polarity of > the expected power source. Then, it's "just" a matter of finding > the appropriate barrel diameter and center post diameter to "fit". > > > Now you could take it apart, but more often just play Russian roulette > > and see if the LEDs light. Why can't manufacturers label the connector > > with (+)- or (-)+ nnV/mmA? I am fed up with just seeing "POWER". > > One gripe *I* have is that the standard scheme for indicating polarity > doesn't fare well as it is scaled. Something like: > > + ----* )---- - > > where the ")" signifying the barrel contact actually wraps around the > "*" signifying the center post. Ink bleed at small scales often turns > this into a guessing game: "is that a '-' or a '+'? Is the line > from that +/- symbol going to the center *pin*? Or, the enclosing > curve??" > > Why not a simple circle with a sign inside? Takes LESS space on the > label (so it could be printed at a larger scale) and removes some of the > ambiguity! > > Or, design devices that are tolerant of polarity reversals! (ideally, > *functioning* with either polarity or at least not giving up the > ghost with "reversed" polarity!) > > For my own, personal items, I label each wall wart with the name of > its mate and write the power requirements on the mate with a "Sharpie" > using the "circled sign" graphic I described accompanied by > voltage and amperage. I have a *white* pen for those items > that have black cases.
I write the name of the gizmo on the wall wart using gold paint marker. (It isn't going to make a wall wart any uglier.) Cheers Phil -- 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 845-480-2058 hobbs at electrooptical dot net http://electrooptical.net
John Larkin wrote:
> > If you but a model K901 Ethernet switch, why doesn't the wart have a > label "For model K901" ?
Because they are usually generic, for multiple models in a company's product line. Big companies like to reduce stock numbers. In some cases there are several revisions of 'K901', each requiring different wall warts. Linksys was good at that. Not only do they change them, but they delete the old information from their support documents. -- You can't have a sense of humor, if you have no sense.
On Mon, 20 Feb 2012 13:06:18 -0500, "Michael A. Terrell"
<mike.terrell@earthlink.net> wrote:

> >John Larkin wrote: >> >> If you but a model K901 Ethernet switch, why doesn't the wart have a >> label "For model K901" ? > > > Because they are usually generic, for multiple models in a company's >product line. Big companies like to reduce stock numbers. In some >cases there are several revisions of 'K901', each requiring different >wall warts. Linksys was good at that. Not only do they change them, >but they delete the old information from their support documents.
How long would it take to slap a sticker on a wart before they ship it? I'd be happy if they'd spend their time doing that, and eliminate some of the zillion twist-ties on everything, and the plastic junk taped all over the line plug. I think there is a trend towards a universal power scheme, namely the USB thing.