DC Adapter question

On Thu, 09 Jun 2005 07:15:46 -0800, (Floyd L.
Davidson) wrote:

David Maynard wrote:

Speaking of 'unregulated' regulated wall worts isn't good
english, logic, engineering, or anything else, except maybe
humor.

That was *your* term, silly as it is.

Wheee... This is fun. Permit me to throw in a few details.

1. A problem with undersized wall warts is ripple. The smaller
current handling xformer power supplies will tend to have undesized
filter capacitors. Running at full load, the 60 or 120Hz ripple
voltage can really screw up a 3 terminal regulator found in most
bottom of the line wireless hardware.

A rough approximation is:
C = I / (120 * V)
whe
C = Cazapitance in Farads
I = Load current in Amps
V = Peak to peak ripple current desired in volts.
So, for this device, I would probably want less than 50mv of ripple at
1.6A load. Pluging:
C = 1.6 / (120 * .05) = 267uF
I've found some of the "replacement" power supplies to have very small
(47uf) cazapitors and sometimes with a very marginal voltage rating.

2. The maximum rating of these wall warts is often based upon self
heating. That's caused by the xformer cores saturating. It's also a
great way to get some free voltage regulation if you don't care about
efficiency. Before the xformer gets too hot, the input/output voltage
curve will tend to flatten somewhat. Some manufacturers take
advantage of this effect by intentionally using undersized xformers
and hopeing that the whole mess doesn't burn down the customers house.
It usually doesn't but it does eventually cook the cheapo phenolic
circuit board, diodes, and cazapitor inside the wall wart.

3. The Dlink DSL-604+ wireless ADSL modem has apparently been FCC
type accepted. However, my attempts to use the FCCID search
abomination to find it by model number was unsuccessful. Duz anyone
have the FCCID number for the DSL-604+? With that, I could lookup the
type of power supply they use and see if it requires regulation.

4. DLink has been using high efficient switching mode power supplies
for quiet a while. They draw no power with no load. They are
smaller, lighter, far more efficient, offer regulated voltage output,
and have short circuit protection. They also generate lots of RFI
which drives the hams nuts. I couldn't find a photo of the DSL-604+
wall wart sold in UK. If it's a switcher, it should probably be
replaced with a switcher as the DSL-604+ may rely on the added voltage
regulation of the power supply. Difficult to tell without a look
inside.

5. The voltage and current ratings are at "nominal" input voltage.
For the US, that means 115VAC. Normal excursions are 105 to 125VAC
input. For the 7.5VDC output, that's 6.8 to 8.2VDC. Neither extreme
will cause a cheap 3 terminal 5VDC regulator with a 1.6VDC dropout
voltage to stop working. LDO regulators are even less of a problem.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558

David Maynard wrote:
Floyd L. Davidson wrote:
David Maynard wrote:

Speaking of 'unregulated' regulated wall worts isn't good
english, logic, engineering, or anything else, except maybe
humor.
That was *your* term, silly as it is.

It is an accurate 'silliness' of your contention that a
regulated supply may have significant voltage rise with a lower
load than it's 'rating' (your original, and correct, warning
about unregulated supplies that you clung to when I brought up
regulated wall worts).

The term was yours, and it is silly (and all the other adjectives
you used to describe it). Which is why *I* didn't use it.

But the whole point to "regulation" is to prevent precisely what
you argue can take place so it would have to be 'unregulated'
for your caution to be true, which would make it an
'unregulated' regulated wall wort, silly as it is.

If you think so, you'd better take a closer look at real life
regulators!

Sometimes the whole point of a "regulator" is ripple reduction
at 60 Hz and it's harmonics. Sometimes the whole point of a
"regulator" is to provide regulation within a very minimal
range.

And sometimes "regulation" means within 20%, sometimes 10% and
sometimes 0.1%.

I suppose I could go on with a longer list of ambiguities, but
those are all well known and should be enough to demonstrate
that your statement about "regulation" just doesn't have a lot
of meaning. The point is that not all regulated power supplies
maintain the same voltage with no load, and that some regulated
power supplies do not regulate well except within a specified
load range. Regardless, your original statement tried to
generalize something specific that generally may not be true.

I really have no idea why you decided to turn a simple matter of
regulated wall worts into a mash of mumbo jumbo. Say someone

I'm sorry you don't understand the technical aspects, but that
does suggest you perhaps shouldn't try to post technical
answers.

wants to replace a dead 5V 2A SMP wall wort. What the hell do
you suggest they get?

A live "5V 2A SMP wall wort".


Whatever, this conversation is finished. You can have the last
words. Just do try for something a little better than
unregulated regulated power, eh?

--
Floyd L. Davidson http://web.newsguy.com/floyd_davidson
Ukpeagvik (Barrow, Alaska)

Floyd L. Davidson wrote:

David Maynard wrote:

Floyd L. Davidson wrote:

David Maynard wrote:

Speaking of 'unregulated' regulated wall worts isn't good
english, logic, engineering, or anything else, except maybe
humor.

That was *your* term, silly as it is.

It is an accurate 'silliness' of your contention that a
regulated supply may have significant voltage rise with a lower
load than it's 'rating' (your original, and correct, warning
about unregulated supplies that you clung to when I brought up
regulated wall worts).


The term was yours, and it is silly (and all the other adjectives
you used to describe it). Which is why *I* didn't use it.


But the whole point to "regulation" is to prevent precisely what
you argue can take place so it would have to be 'unregulated'
for your caution to be true, which would make it an
'unregulated' regulated wall wort, silly as it is.


If you think so, you'd better take a closer look at real life
regulators!

Sometimes the whole point of a "regulator" is ripple reduction
at 60 Hz and it's harmonics. Sometimes the whole point of a
"regulator" is to provide regulation within a very minimal
range.

And sometimes "regulation" means within 20%, sometimes 10% and
sometimes 0.1%.

Funny you mention "real life" and then wander off into a fantasy land of
speculation.

The fact of the "real life" matter is that none of your "sometimes"
speculations apply to SMP wall worts.


I suppose I could go on with a longer list of ambiguities, but
those are all well known and should be enough to demonstrate
that your statement about "regulation" just doesn't have a lot
of meaning. The point is that not all regulated power supplies
maintain the same voltage with no load, and that some regulated
power supplies do not regulate well except within a specified
load range. Regardless, your original statement tried to
generalize something specific that generally may not be true.

That is what I meant by your mash of mumbo jumbo. One can 'speculate'
anything but the real world case is that a regulated wall wort will have
none of the characteristics you ponder as 'possible'.


I really have no idea why you decided to turn a simple matter of
regulated wall worts into a mash of mumbo jumbo. Say someone


I'm sorry you don't understand the technical aspects, but that
does suggest you perhaps shouldn't try to post technical
answers.

Oh I understand them just fine and design them too. The difference is I
don't try to obfuscate the practical matters with theoretical 'anything
could be' speculations.

wants to replace a dead 5V 2A SMP wall wort. What the hell do
you suggest they get?


A live "5V 2A SMP wall wort".

Wouldn't you be terrified it could be one of those unsuitable
'possibilities' of inferior regulation you just ranted about?


Whatever, this conversation is finished. You can have the last
words. Just do try for something a little better than
unregulated regulated power, eh?


No need as it's appropriately silly as it stands.

On Wed, 08 Jun 2005 15:27:10 -0500, David Maynard
wrote:

I don't feel like bringing the network down to put a meter to it but I'd
bet the 5V 2.5A wall wort to my D-link 614+ is a switcher because I don't
see any way a 12.5VA transformer could fit in the 1.75x2.25x1 inch case,
plus there's no weight to it, and the model number, SMP-xxxxx, looks
suspiciously like an engineer's "Switch Mode Power" supply acronym.

I just happen to have a DLink DI-614+ here. DLink uses several
sources of power supplies. This one is a:
Fairway Electronics LTD
Model: WN10A-050U
Input: 100-240VAC 1.0A Max 50-60Hz
Output: +5.0VDC 2.5A
With such a wide input voltage range, it has to be a switcher.
http://www.ncs-fairway.com/catalog/page10.pdf
Note that the 5VDC output is regulated (to 5%).

I dunno about the 70% efficiency. Seems a bit low.
Interesting that the sticker says 2.5A while the data sheet says 2.0A
output. Oh-oh.




--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831.336.2558 voice http://www.LearnByDestroying.com
#
# AE6KS

Jeff Liebermann wrote:

On Wed, 08 Jun 2005 15:27:10 -0500, David Maynard
wrote:


I don't feel like bringing the network down to put a meter to it but I'd
bet the 5V 2.5A wall wort to my D-link 614+ is a switcher because I don't
see any way a 12.5VA transformer could fit in the 1.75x2.25x1 inch case,
plus there's no weight to it, and the model number, SMP-xxxxx, looks
suspiciously like an engineer's "Switch Mode Power" supply acronym.


I just happen to have a DLink DI-614+ here. DLink uses several
sources of power supplies. This one is a:
Fairway Electronics LTD
Model: WN10A-050U
Input: 100-240VAC 1.0A Max 50-60Hz
Output: +5.0VDC 2.5A
With such a wide input voltage range, it has to be a switcher.

Thanks. Knew it had to be unless someone had invented featherweight iron

http://www.ncs-fairway.com/catalog/page10.pdf

Oh, I wish that was the one that came with mine. Mine has the plug on the
end, which means it sticks almost 3 inches out the wall, if you plugged it
into a wall outlet.

Note that the 5VDC output is regulated (to 5%).

That's the tolerance. They don't seem to mention load/line regulation %.


I dunno about the 70% efficiency. Seems a bit low.
Interesting that the sticker says 2.5A while the data sheet says 2.0A
output. Oh-oh.

Look at the second 5 volt job 5 lines down: 2.5A 12.5W

But wait! Couldn't the transformer be very light if it were ferrite and
worked at a much higher frequency than 60 Hz? Oh, never mind.

Phil Weldon

"David Maynard" wrote in message
...
Jeff Liebermann wrote:

On Wed, 08 Jun 2005 15:27:10 -0500, David Maynard
wrote:


I don't feel like bringing the network down to put a meter to it but I'd
bet the 5V 2.5A wall wort to my D-link 614+ is a switcher because I don't
see any way a 12.5VA transformer could fit in the 1.75x2.25x1 inch case,
plus there's no weight to it, and the model number, SMP-xxxxx, looks
suspiciously like an engineer's "Switch Mode Power" supply acronym.


I just happen to have a DLink DI-614+ here. DLink uses several
sources of power supplies. This one is a:
Fairway Electronics LTD
Model: WN10A-050U
Input: 100-240VAC 1.0A Max 50-60Hz
Output: +5.0VDC 2.5A
With such a wide input voltage range, it has to be a switcher.

Thanks. Knew it had to be unless someone had invented featherweight iron


http://www.ncs-fairway.com/catalog/page10.pdf

Oh, I wish that was the one that came with mine. Mine has the plug on the
end, which means it sticks almost 3 inches out the wall, if you plugged it
into a wall outlet.

Note that the 5VDC output is regulated (to 5%).

That's the tolerance. They don't seem to mention load/line regulation %.


I dunno about the 70% efficiency. Seems a bit low. Interesting that the
sticker says 2.5A while the data sheet says 2.0A
output. Oh-oh.

Look at the second 5 volt job 5 lines down: 2.5A 12.5W

On Fri, 10 Jun 2005 21:18:00 -0500, David Maynard
wrote:

http://www.ncs-fairway.com/catalog/page10.pdf

Oh, I wish that was the one that came with mine. Mine has the plug on the
end, which means it sticks almost 3 inches out the wall, if you plugged it
into a wall outlet.

Most of mine are plugged into power strips where such a compact
arrangement is benificial. However, there are ways to deal all manner
of wall warts.
http://802.11junk.com/jeffl/pics/dri...l-wart-01.html

Interesting that the sticker says 2.5A while the data sheet says 2.0A
output. Oh-oh.

Look at the second 5 volt job 5 lines down: 2.5A 12.5W

Oops. I didn't notice the "U" suffix. Thanks.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558

Phil Weldon wrote:

But wait! Couldn't the transformer be very light if it were ferrite and
worked at a much higher frequency than 60 Hz? Oh, never mind.

Hehe. Sure. That's how a switcher does it.



Phil Weldon

"David Maynard" wrote in message
...

Jeff Liebermann wrote:


On Wed, 08 Jun 2005 15:27:10 -0500, David Maynard
wrote:



I don't feel like bringing the network down to put a meter to it but I'd
bet the 5V 2.5A wall wort to my D-link 614+ is a switcher because I don't
see any way a 12.5VA transformer could fit in the 1.75x2.25x1 inch case,
plus there's no weight to it, and the model number, SMP-xxxxx, looks
suspiciously like an engineer's "Switch Mode Power" supply acronym.


I just happen to have a DLink DI-614+ here. DLink uses several
sources of power supplies. This one is a:
Fairway Electronics LTD
Model: WN10A-050U
Input: 100-240VAC 1.0A Max 50-60Hz
Output: +5.0VDC 2.5A
With such a wide input voltage range, it has to be a switcher.

Thanks. Knew it had to be unless someone had invented featherweight iron



http://www.ncs-fairway.com/catalog/page10.pdf

Oh, I wish that was the one that came with mine. Mine has the plug on the
end, which means it sticks almost 3 inches out the wall, if you plugged it
into a wall outlet.


Note that the 5VDC output is regulated (to 5%).

That's the tolerance. They don't seem to mention load/line regulation %.


I dunno about the 70% efficiency. Seems a bit low. Interesting that the
sticker says 2.5A while the data sheet says 2.0A
output. Oh-oh.

Look at the second 5 volt job 5 lines down: 2.5A 12.5W

Jeff Liebermann wrote:

On Fri, 10 Jun 2005 21:18:00 -0500, David Maynard
wrote:


http://www.ncs-fairway.com/catalog/page10.pdf

Oh, I wish that was the one that came with mine. Mine has the plug on the
end, which means it sticks almost 3 inches out the wall, if you plugged it
into a wall outlet.


Most of mine are plugged into power strips where such a compact
arrangement is benificial. However, there are ways to deal all manner
of wall warts.
http://802.11junk.com/jeffl/pics/dri...l-wart-01.html

LOL.

Now HOW did you get a picture of my power strip?



Interesting that the sticker says 2.5A while the data sheet says 2.0A
output. Oh-oh.

Look at the second 5 volt job 5 lines down: 2.5A 12.5W


Oops. I didn't notice the "U" suffix. Thanks.

On Fri, 10 Jun 2005 23:57:58 -0700, in alt.internet.wireless , Jeff
Liebermann wrote:

Most of mine are plugged into power strips where such a compact
arrangement is benificial. However, there are ways to deal all manner
of wall warts.
http://802.11junk.com/jeffl/pics/dri...l-wart-01.html

do you not find that the adaptors in the middle get kinda hot? I can
practically cook toast on the power strip under my desk at work.
--
Mark McIntyre
CLC FAQ http://www.eskimo.com/~scs/C-faq/top.html
CLC readme: http://www.ungerhu.com/jxh/clc.welcome.txt

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