A Question about Wall Warts

Well, MAYBE for a laptop; but 90% of the periphs use a wallwart bought from the lowest bidder. That hurts when there's a recall, al-la Apple and Dell w/ Delta supplies...

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I like those. But I have plenty of old extension cords and wire nuts laying around. Of course mine won't be stackable like those but they will do.

I'm still pissed at PalmOne. My Zire has a USB connection and a separate power charging connector. I measured the voltage from the wall wart and it is 5.5 and it is rated for 100ma. IIRC the USB spec calls for 5 volts and 500ma. A slight change in the charging circuitry and they could have done away with the wall wart and power connector. Dumbasses.

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Mark Healey
marknews(at)healeyonline(dot)com

90% of EVERYTHING is bought from the lowest bidder...to the specifications provided by the buyer. What's your point and how does it relate to the (un)safety of substituting power components that do not meet the SYSTEM design parameters? mike

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one

language,

Last January we hired our (only) contractor to fky out for a week and work on our PBXes. He's from Cleveland, and when we went into the hardware store to buy some consumables, he said, "Where are all the snowblowers???" ;-)

Honestly, Ed, I've never seen one!

They must have 'em, because there's snow up in the mountains, but here in the flatlands, never.

as a

the

Yeah, we had to spend a bunch of time at work checking the power bricks on our Dell laptops. Mine had a recalled 'dud', so our Dell tech gave me his, and he kept the dud and later exchanged it. I don't know how many duds there were, but we have hundreds of laptops and he probably had dozens of duds. What crackes me up is when he has to call in an under warranty keyboard repair. Dell sends out a new one, with a shipping label so that he can put the old one back into the box and ship it back to them. When they get it, it probably goes into the trash bin. :-P

My guess is it goes in another (bigger) box with some others and is sent back for credit to whoever made it.

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I had to explain to someone here in Florida what a Snow shovel was made for. :(

On the other hand, they make a great dustpan for cleaning up the garage floor.

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and

here

I thought for a minute you were gonna tell us that they make a great pooper scooper for the 'gators you guys have crawling around in your back yards. ;-)

Make sure you keep us up to date on your hassle with the knothead from the other newsgroup.

I read a "cool" story in a school reader when I was a kid about a long-haul refrigerator truck driver buying a snowman from some kids up north to bring back to his kids in Florida.

Tom

I've noticed a trend recently toward orienting the AC jacks outward on the strips, so that plugging in the big transformer does not rob space from the other jacks. Sorry, there's no brand name on the one I'm using to power my current setup, or I'd mention it.

Before you get too up in arms about that, realize two things. First, it isn't always trivial to change a design to accommodate a lower charge current. Second, the 500mA capability of the USB spec is meant to be used for data transmission, so there won't be a lot left over for battery charging. Third [1], it may be an iffy thing to allow data comm and power circuits to share their supplies.

[1] There are three types of people in the world: those who can count, and those who cannot.

I pretty sure it is meant do provide power to things that don't require a lot, like my card readers. Why else would they have a +5VDC line there.

It works on my phone (Motorola V3).

The data transmission between a PDA and the computer is pretty brief and occurs only when you sync. Most of the time it would just be drawing current.

So you wouldn't go for data over the power companies lines.

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Mark Healey
marknews(at)healeyonline(dot)com

Well, I don't know plenty about USB, but the only USB devices I have used that do not use a separate power source are thumb drives.

So I see. But now I have a new question...

...what's the load on the computer when multiple devices are on-line? It might not take much to load the bus into unreliability, if a lot of the devices are bus-powered.

Well, that depends. Power line carrier isn't used much anymore, but fiber lines go "over" the power lines, so to speak :-)

That the wallwart is in fact an AOT, and the circuit takes into account the fact that the next batch may not be identical.

{An engineer I knew 25 years ago would draw a circuit with a NPN and label it "AOT" -- when you'd ask he'd say "That? Any old thing will work there..."}

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A host is a host from coast to coast.................wb8foz@nrk.com
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

I don't know. The spec says it should provide 500ma. I suppose if you have more than 500ma worth of devices things start getting twitchy.

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Mark Healey
marknews(at)healeyonline(dot)com

This is just nutz! "FACT" huh??? I sure hope you don't design this way. The next batch may not be IDENTICAL, but it'd sure better meet the specification required by the system. It may be a loose spec, but it's a spec none the less and you can't count on just ANY wall wart meeting ANY old spec.

I'd be glad to show you the exploded battery when I attempted to substitute a laptop wart...but I got it outside when it started hissing. After it blew up, I went looking...after I cleaned the electrolyte off my face...but never found most of the exploded cell. Bad design? You bet! And there are a lot of bad designs in the world.

Take as much risk as you want, but it's irresponsible to tell people they can substitute wall warts. Sometimes you can, but sometimes you can't. Are you feeling lucky? mike

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The USB spec is 500ma PER PORT. (I have a cheap 4-port USB 2.0 hub that came with a 5V 2.5A wall wart.)

Awol awol [AT] i-hacked [D()T] com

Check eBay.

My wife bought a cable for her Palm Tungsten (E3?) that does exactly what you want. Plugs into USB port, splits to data cable & power plug for the Palm. Charges the Palm and transfers data with no problems. Was under $5, and I bet they make one for your model too.

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