7805 OK to get hot (do I need a heatsink)

[Don Klipstein]

In article <6l9So.17598$Zf2.964@newsfe17.iad>, Jamie wrote:

Don Klipstein wrote:

In article <RC7So.36024$uS7.18304@newsfe23.iad>, Jamie wrote:

Jack B. Pollack wrote:


The story of a linear regulator IC producing enough heat to invite
asking about heatsinking it

Use a switching regulator ?

http://www.dimensionengineering.com/de-sw050.htm

http://www.simplecircuitdiagram.com/2009/05/20/5v-switching-regulator-
very-simple-circuit/

Go here and design it on line..

http://www.national.com/analog/power/simple_switcher?
gclid=CJHYoOmwjaYCFUdN4AodR297oQ

Jamie

As said elsewhere in this thread, this is sci.electronics.basics, and
the fellow starting this thread got something working here except for
maybe to maybe-likely need or at least wanting a heatsink.

And, I would not ask a newbie to trash something that the newbie already
put effort into making work, with exception of maybe-likely need for a
heatsink.

The heatsink will cost the newbie an order of magnitude less than
rebuilding as switchmode the linear regulator solution that the newbie
appears to have about 90% of the way worked out.

So, for bringing up switchers as opposed to linear regulators, I would
look for much more diplomatic ways. I would put such ways in a class
dependent on the newbie wanting to build more regulators,

or, in terms of offering advice to next-in-line newbies that want to
make a voltage regulator circuit.
(Should newbies be good targets for making their electronics learning
experiences taking the plunge into switchmode regulators on the very day
they could be purchasing the 1st IC exposed to a soldering iron at their
hands. Meanwhile, we have a newbie that got a linear one largely working
and then posted here.)

When a newbie builds something and it works, or the newbie asks for help
in getting something to work, I would want to encourage the newbie. It
appears to me that suggestion to trash something 90% of the way working
and then go back to Square One is discouragement.

Something I see - I would let people actually building something to
either take pride in what they built, or to take pride in how they would
be ashamed to repeat what they did in their younger 1st-project days.

So, I would say, let them follow through, guide them but don't turn them
back unless they're on some outright collision course, give them advice
when they ask for it, and *let them complete something 80-90% done* when
feasible!

Should the newbie go on to build more, especially related, electronics
projects, then fair chance the newbie will be interested in how to make
them better than Model A.

If I knew what I know now back when I first made my own Model A
electronic project, constructed outside the 60-or-whatever-in-1 "kit"
from Radio Shack (in their better days) on some birthday or Christmas in
the mid 1970's, I would have saved my 1st "free bird" electronic
contraption in a trophy display case. (IIRC, that was a Hartley audio
oscillator by intent, but ended up being a "ringing choke" one.)

Ok, understood how ever, the first link I gave was a direct drop in
replacement for the 7805 with out changing nothing to the remainder of
the design..

Did not you say before switchmode? How is that drop-in replacement?
Don't those require inductors?

I did notice "pin for pin compatible with the common 78xx" in your 1st
link, so I decided to check further.

As shown in what your 1st link provides,

http://www.dimensionengineering.com/datasheets/DE-SW0XX.pdf:

O, I see... Looks to me like the IC has the inductor built in.

Now, are DE-SW0xx regulators available from Digi-Key or the like?
(I tried looking there - appears to me the answer is no.)

Hey, your link says in small quantities they're $15 each! (Plus
shipping, thankfully $1.25 for what appears to me to be postal mail,
likely a week or more for this being international.)

It's obvious by now that the OP was only looking for a solution and
not wanting to expand their horizons. If you looked at the first link, I
think you would agree that it'd be the choice for those just wanting to
getting it working better and not do a total overhaul.

Additional options were supplied in the event that wasn't the case.
--

- Don Klipstein (don@misty.com)

 

[John G]

on 28/12/2010, Don Klipstein supposed :

In article <RC7So.36024$uS7.18304@newsfe23.iad>, Jamie wrote:
Jack B. Pollack wrote:

The story of a linear regulator IC producing enough heat to invite
asking about heatsinking it

Use a switching regulator ?

http://www.dimensionengineering.com/de-sw050.htm

http://www.simplecircuitdiagram.com/2009/05/20/5v-switching-regulator-
very-simple-circuit/

Go here and design it on line..

http://www.national.com/analog/power/simple_switcher?
gclid=CJHYoOmwjaYCFUdN4AodR297oQ

Jamie

As said elsewhere in this thread, this is sci.electronics.basics, and
the fellow starting this thread got something working here except for
maybe to maybe-likely need or at least wanting a heatsink.

And, I would not ask a newbie to trash something that the newbie already
put effort into making work, with exception of maybe-likely need for a
heatsink.

The heatsink will cost the newbie an order of magnitude less than
rebuilding as switchmode the linear regulator solution that the newbie
appears to have about 90% of the way worked out.

So, for bringing up switchers as opposed to linear regulators, I would
look for much more diplomatic ways. I would put such ways in a class
dependent on the newbie wanting to build more regulators,

or, in terms of offering advice to next-in-line newbies that want to
make a voltage regulator circuit.
(Should newbies be good targets for making their electronics learning
experiences taking the plunge into switchmode regulators on the very day
they could be purchasing the 1st IC exposed to a soldering iron at their
hands. Meanwhile, we have a newbie that got a linear one largely working
and then posted here.)

When a newbie builds something and it works, or the newbie asks for help
in getting something to work, I would want to encourage the newbie. It
appears to me that suggestion to trash something 90% of the way working
and then go back to Square One is discouragement.

Something I see - I would let people actually building something to
either take pride in what they built, or to take pride in how they would
be ashamed to repeat what they did in their younger 1st-project days.

So, I would say, let them follow through, guide them but don't turn them
back unless they're on some outright collision course, give them advice
when they ask for it, and *let them complete something 80-90% done* when
feasible!

Should the newbie go on to build more, especially related, electronics
projects, then fair chance the newbie will be interested in how to make
them better than Model A.

If I knew what I know now back when I first made my own Model A
electronic project, constructed outside the 60-or-whatever-in-1 "kit"
from Radio Shack (in their better days) on some birthday or Christmas in
the mid 1970's, I would have saved my 1st "free bird" electronic
contraption in a trophy display case. (IIRC, that was a Hartley audio
oscillator by intent, but ended up being a "ringing choke" one.)

Don,
I have left your comments intact because they need repeating here once
a week and even on Sci Electronics Design fairly often.

There are some people here (I wont boost their ego by calling them
engineers, tho some may be.)who always want to suggest the latest and
greatest design idea to somone like the current OP who just needs a
little help with his next faltering step.

I have been fixing electronic things from WWII aircraft radios thru
guided missiles and on to computers so I consider I have a lot of
experience. 60 years and schoollboy stuff before that.

I would not attempt under any circumstance to build an SMPS from the
description offered above. I am quite capable of building things but to
be told and SMPS will fix the problem is laughable.

Difficult and very dangerous for a beginner.

--
John G

 

[DJ Delorie]

John G <greentest@ozemail.com.au> writes:

I would not attempt under any circumstance to build an SMPS from the
description offered above. I am quite capable of building things but
to be told and SMPS will fix the problem is laughable.

Difficult and very dangerous for a beginner.

My latest project has three SMPSs on it (DC-DC buck regulators), and
each of them is about the same size as a TO-220 part. Part count ranges
from 4 to 8 parts, compared to 3 for a linear regulator (including
in/out capacitors). The SMPSs do not even get warm to the touch (8-16v
in, 5V@1A max, 3.3/1.2v@0.5A), compared to skin-blistering temperatures
of a 7805. I wonder how many newbies blindly assumed they could draw 1
amp from a 15v supply through a 7805, and either hurt themselves or
damaged the parts?

With todays SMPS chips and wide range of linear regulators, "difficulty"
is on par with linears, and "dangerous" is relative.

I see no reason why newbies should avoid SMPSs "just because", and in
cases where a linear would generate enough heat to be dangerous or
damaging, a switcher should be considered.

 

[David Eather]

On 28/12/2010 8:13 AM, Winston wrote:

David Eather wrote:

(...)

At a maximum of a few cents per year savings in power that
is *never* going to happen with this type of consumer product.

Never is a long time.

Perhaps you've seen the evolution of the wall wart supply
from the old linear transformer type to the new switch mode
type over the last few years? I sure have.

I suppose that approach is the best answer for manufacturers
considering shipping cost and 'energy star' regulatory compliance.

Phase one was the movement of the regulator outside of the
main enclosure. Phase two is boosting the efficiency of
the regulator so less power is converted to heat.

I'm all for it.

From: http://en.wikipedia.org/wiki/AC_adapter

"The report concluded that about 32 billion kilowatt-hours (kWh) per
year, about 1% of total electrical energy consumption, could be saved in
the United States by: replacing all linear power supplies"

I bet they didn't say what the cost (in kilowatt hours) was to
manufacture and ship all those power supplies was.

For many applications, wholesale, mandated replacment makes no economic
or environmental sense at all. In particular, low use applications like
electric razors that are recharge for an hour or two per week and wall
warts associated with short life consumer products such as iPods. In
those cases you don't "force" any change to existing products, you just
make a requirement for new products to have compliant power supplies.

If you really wanted to save energy then you (as a government) would
mandate a few standard power supply types (I am talking about wall wart
and external computer/computer peripheral power supplies). You would
allow exceptions for a unit price based fee, and require the power
supply to be provided only as a *separate* item.

(...)

But you propose to use the enclosure as a heatsink for the switch mode
design, so this is a fallacious argument especially in light of a less
than 2 watt dissipation

Yes, essentially make the old 'battery door' an aluminum heatsink
and sink thermal power through it. Way cooler than trying to
push that power through a little PVC door.

So it's design overkill and the switchmode supply would only need
to lose ~1 watt with a junction rise of ~5 C.

I've been accused of worse.

There is no pay-off for collecting new components, designing, and then
implementing a new circuit to produce exactly 1 item which will save a
few cents of electricity per year.

Of course there is a payoff.

The name of the group is sci.electronics.basics,
a forum for discussion of electronics.

The payoff is in understanding a better approach
from an engineering perspective.

I am here to learn. I appreciate it when someone
points out a better way to address a problem.

In that case post your own thread.

I was placing myself in the position of the OP.
Lots of times I *am* the OP.

The OP wanted to know if the heat
dissipated from a linear regulator was a problem. In this case a yes/no
answer. Yes it might be a bit of a problem, but a small heatsink will
fix that.

I answered both in my original reply.

* Yes, it is a problem.
* Yes you can use a linear if you pull heat out of the regulator.

* There is a better approach.

Especially if it means my speaker enclosure doesn't melt.

2 watts! :-/

Recall the original approach was to place the regulator
completely within the 2 'AAA' battery compartment.

What is the temperature rise of a resistor dissipating
two watts into a plastic enclosure that has only one
path to ambient measuring 10 mm x 50 mm through a plastic
door that has a thermal resistance of 1300 C per watt?

Answer: Too Hot.

(and thanks for the adult argument)

It is in the finest tradition of USENET.

Thank you.

--Winston

 

[JW]

On Mon, 27 Dec 2010 16:47:34 -0500 Jamie
<jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote in Message id:
<RC7So.36024$uS7.18304@newsfe23.iad>:

Go here and design it on line..

http://www.national.com/analog/power/simple_switcher?gclid=CJHYoOmwjaYCFUdN4AodR297oQ

Slick! Thanks for the link. That will definitely come in handy.

 

[Michael A. Terrell]

David Eather wrote:

On 28/12/2010 8:13 AM, Winston wrote:
David Eather wrote:

At a maximum of a few cents per year savings in power that
is *never* going to happen with this type of consumer product.

Never is a long time.

Perhaps you've seen the evolution of the wall wart supply
from the old linear transformer type to the new switch mode
type over the last few years? I sure have.

I suppose that approach is the best answer for manufacturers
considering shipping cost and 'energy star' regulatory compliance.

Phase one was the movement of the regulator outside of the
main enclosure. Phase two is boosting the efficiency of
the regulator so less power is converted to heat.

I'm all for it.

From: http://en.wikipedia.org/wiki/AC_adapter

"The report concluded that about 32 billion kilowatt-hours (kWh) per
year, about 1% of total electrical energy consumption, could be saved in
the United States by: replacing all linear power supplies"

I bet they didn't say what the cost (in kilowatt hours) was to
manufacture and ship all those power supplies was.

Much less than the equipment they were shipped with.

For many applications, wholesale, mandated replacment makes no economic
or environmental sense at all. In particular, low use applications like
electric razors that are recharge for an hour or two per week and wall
warts associated with short life consumer products such as iPods. In
those cases you don't "force" any change to existing products, you just
make a requirement for new products to have compliant power supplies.

If you really wanted to save energy then you (as a government) would
mandate a few standard power supply types (I am talking about wall wart
and external computer/computer peripheral power supplies). You would
allow exceptions for a unit price based fee, and require the power
supply to be provided only as a *separate* item.

Right. I bought a S5200 digital camera about five years ago. the
power supply was sold seperately. I hasn't been in stock since then. I
finally gave up. It is a 5 V 2.5A supply with a coaxial connecter for
the camera. It was also in the $50 range.

Selling the power supply as a seperate item would stop most people
from buying a product.

Recall the original approach was to place the regulator
completely within the 2 'AAA' battery compartment.

What is the temperature rise of a resistor dissipating
two watts into a plastic enclosure that has only one
path to ambient measuring 10 mm x 50 mm through a plastic
door that has a thermal resistance of 1300 C per watt?

Answer: Too Hot.

(and thanks for the adult argument)

It is in the finest tradition of USENET.

Thank you.

--
For the last time: I am not a mad scientist, I'm just a very ticked off
scientist!!!

 

[Michael Robinson]

"Jack B. Pollack" <N@NE.nothing> wrote in message
news:I8ydnZswuYipl4XQnZ2dnUVZ_omdnZ2d@earthlink.com...

I am charging an iPod using a 7805 1amp regulator. With the iPod screen on
and charging I am drawing .17 amps. The Vreg is getting almost hot enough
so that you cant touch it.

Should this be happening drawing only .17amps? Is it OK?
Should I use a heat sink on the Vreg?
If yes, I am planning on putting the Vreg in the battery compartment that
holds 2 AAA batteries. I doubt that a standard heat sink will fit. How
would you suggest that I make my own that might fit?


Full explanation of what I am doing for those interested:

I have a portable iPod speaker that charges the older iPods through 12V on
the FireWire pin (on the dock connector). My new iPod just charges through
the 5V USB pin. I opened the speaker and cut the trace going to the 12V
FireWire pin. This got rid of the message that the iPod doesn't support
FireWire. I then connected a voltage regulator to the 12V wall-wart power

Okay, do the math. If you have 12 volts (you should measure it) coming in
to the 7805, 5 volts going out of the 7805, and .17 amps, then the power it
has to dissipate is current times voltage, i.e. 7 times .17 for 1.2 watts.
And as someone else pointed out, an unregulated wall wart likely puts out
more than 12 volts. Your 7805 could be dissipating something approaching a
couple of watts, which is a lot.
You can get rid of the problem easily by inserting a power resistor between
the wall wart and the 7805. Measure the wall wart voltage and calculate the
resistor value you need to result in 8 volts at the 7805 input. Then the
chip will only have to dissipate 3 times .17 or about half a watt, which it
can do even without a heatsink.
The 7805 needs two or three volts headroom, so to caculate the power
resistor, take the wall wart voltage, subtract 8, and divide by .17. Let's
say your wallwart puts out 13 volts when running the device (NOT the open
circuit voltage). So you need a resistor that drops 5 volts at .17 amps.
That's about 30 ohms.
Don't forget bypass caps for the chip. Also, the power resistor will have
an effect on the regulator's ability to provide surge current, so you might
want to upsize the output cap.

 

[Jamie]

Jon Kirwan wrote:

On Mon, 27 Dec 2010 16:47:34 -0500, Jamie
jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote:


http://www.national.com/analog/power/simple_switcher?gclid=CJHYoOmwjaYCFUdN4AodR297oQ


Well, damn! Impressive start. But then it eventually moves
you towards, "A Sign-On or Personal Workspace IS required for
Technical Support, Sample Orders, and WEBENCHŽ Designer Tools
use." So to actually get access to the tool, I need to do a
little sign-on jig. Fancy bait for such a simple hook.

Jon
Really, I didn't have to sign on.

I put some numbers in there and it started the app, did the cals, and
presented me with some results and a list of parts.

Maybe you were going elsewhere?


Jamie

 

[whit3rd]

On Dec 26, 7:38 pm, "Jack B. Pollack" <N...@NE.nothing> wrote:

I am charging an iPod using a 7805 1amp regulator. With the iPod screen on
and charging I am drawing .17 amps. The Vreg is getting almost hot enough so
that you cant touch it.

(starting with 15VDC regulated power)...

A heatsink, or a series resistor from +15 to the regulator input,
are indicated. If it's too hot to touch, it could melt the plastic
enclosure...

If you're sure full current is under, say, 0.25 A, the addition of a
27 ohm, 2W resistor will move most of the heat dissispation
from the regulator IC to the power resistor. Such resistors
are less expensive than good heatsinks...

 

[Jon Kirwan]

On Tue, 28 Dec 2010 18:29:13 -0500, Jamie
<jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote:

Jon Kirwan wrote:
On Mon, 27 Dec 2010 16:47:34 -0500, Jamie
jamie_ka1lpa_not_valid_after_ka1lpa_@charter.net> wrote:


http://www.national.com/analog/power/simple_switcher?gclid=CJHYoOmwjaYCFUdN4AodR297oQ


Well, damn! Impressive start. But then it eventually moves
you towards, "A Sign-On or Personal Workspace IS required for
Technical Support, Sample Orders, and WEBENCHŽ Designer Tools
use." So to actually get access to the tool, I need to do a
little sign-on jig. Fancy bait for such a simple hook.

Jon
Really, I didn't have to sign on.

I put some numbers in there and it started the app, did the cals, and
presented me with some results and a list of parts.

Maybe you were going elsewhere?

Yes, I got the same stuff. Then I picked a specific line
item and asked for a design to be completed with THAT
particular part. That's when the fun happened.

I quoted the message I got.

Jon

 

[F. Bertolazzi]

krw@att.bizzzzzzzzzzzz:

There is no "best" answer.

Apart from replacing the wall wart with a nowadays inexpensive 5V
switchmode wall wart and throwing away all the other crap? ;-)

 

[krw@att.bizzzzzzzzzzzz]

On Thu, 30 Dec 2010 19:55:08 +0100, "F. Bertolazzi"
<TOGLIeset@MAIUSCOLEtdd.it> wrote:

krw@att.bizzzzzzzzzzzz:

There is no "best" answer.

Apart from replacing the wall wart with a nowadays inexpensive 5V
switchmode wall wart and throwing away all the other crap? ;-)

Hey! No fair thinking outside the box!

 

[Michael A. Terrell]

"krw@att.bizzzzzzzzzzzz" wrote:

On Thu, 30 Dec 2010 19:55:08 +0100, "F. Bertolazzi"
TOGLIeset@MAIUSCOLEtdd.it> wrote:

krw@att.bizzzzzzzzzzzz:

There is no "best" answer.

Apart from replacing the wall wart with a nowadays inexpensive 5V
switchmode wall wart and throwing away all the other crap? ;-)

Hey! No fair thinking outside the box!

What box? People are lucky to even have a plastic bag, these days.


--
For the last time: I am not a mad scientist, I'm just a very ticked off
scientist!!!

 

[F. Bertolazzi]

Michael A. Terrell:

What box? People are lucky to even have a plastic bag, these days.

Unless they live in Italy. From today on, distribution of plastic bags is
prohibited in Italy. Only paper or bio-degradable plastic (a junk made with
corn) bags are allowed. As if these were biodegradable, while you can find,
in the dumps, 50 years old newspapers still perfectly readable.

I was puzzled why our government would do such a stupid thing.
The answer is easy: it's a law of the previous leftist government, whose
application was postponed for two years, this year they had other reforms
to do and did not care to defer it for another year.

 

[krw@att.bizzzzzzzzzzzz]

On Sat, 1 Jan 2011 19:31:33 +0100, "F. Bertolazzi" <TOGLIeset@MAIUSCOLEtdd.it>
wrote:

Michael A. Terrell:

What box? People are lucky to even have a plastic bag, these days.

Unless they live in Italy. From today on, distribution of plastic bags is
prohibited in Italy. Only paper or bio-degradable plastic (a junk made with
corn) bags are allowed. As if these were biodegradable, while you can find,
in the dumps, 50 years old newspapers still perfectly readable.

I was puzzled why our government would do such a stupid thing.

They're the government. That's what they do!

The answer is easy: it's a law of the previous leftist government, whose
application was postponed for two years, this year they had other reforms
to do and did not care to defer it for another year.

I wish they'd decide they've had enough "reforms" and have passed enough laws,
so just stay home for a few years. The rest of us might catch up.

 

[F. Bertolazzi]

krw@att.bizzzzzzzzzzzz:

On Sat, 1 Jan 2011 19:31:33 +0100, "F. Bertolazzi" <TOGLIeset@MAIUSCOLEtdd.it
wrote:

I was puzzled why our government would do such a stupid thing.

They're the government. That's what they do!

LOL. But leftist governments are much better at screwing up things.

I wish they'd decide they've had enough "reforms" and have passed enough laws,
so just stay home for a few years. The rest of us might catch up.

In fact the reform of italian universities tries to erase 30 years of
damage done by the sinisters to gain control of education.

In fact this reform has been a restoration to the previous rules.

 

[krw@att.bizzzzzzzzzzzz]

On Sat, 1 Jan 2011 22:11:01 +0100, "F. Bertolazzi" <TOGLIeset@MAIUSCOLEtdd.it>
wrote:

krw@att.bizzzzzzzzzzzz:

On Sat, 1 Jan 2011 19:31:33 +0100, "F. Bertolazzi" <TOGLIeset@MAIUSCOLEtdd.it
wrote:

I was puzzled why our government would do such a stupid thing.

They're the government. That's what they do!

LOL. But leftist governments are much better at screwing up things.

Yes, we see that too.

I wish they'd decide they've had enough "reforms" and have passed enough laws,
so just stay home for a few years. The rest of us might catch up.

In fact the reform of italian universities tries to erase 30 years of
damage done by the sinisters to gain control of education.

At least you're trying.

In fact this reform has been a restoration to the previous rules.

Maybe we'll learn some day.

 

[Jasen Betts]

On 2011-01-01, F. Bertolazzi <TOGLIeset@MAIUSCOLEtdd.it> wrote:

Michael A. Terrell:

What box? People are lucky to even have a plastic bag, these days.

Unless they live in Italy. From today on, distribution of plastic bags is
prohibited in Italy. Only paper or bio-degradable plastic (a junk made with
corn) bags are allowed. As if these were biodegradable, while you can find,
in the dumps, 50 years old newspapers still perfectly readable.

I don't think they found fragments of paper bags collected by ocean
currents - see "pacific garbage patch"

a landfill is like a swamp, anything thrown in there is deprived of
oxygen, cellulose will last indefinately - see "bog oak"


--
⚂⚃ 100% natural

 

[F. Bertolazzi]

Jasen Betts:

I don't think they found fragments of paper bags collected by ocean
currents - see "pacific garbage patch"

But also few plastic bags. Most of it is plastic bottles.

Since the rivers that flow into the Mediterranean bring less water than
what evaporates, there is a strong incoming current, so none of our garbage
can get out, it can only get in. Despite of that, and of the fact that
about 100 million people live in it's drainage basin, we have nothing like
it in our sea.

And probably neither you: "The size of the patch is unknown, as large items
readily visible from a boat deck are uncommon. Most debris consists of
small plastic particles suspended at or just below the surface, making it
impossible to detect by aircraft or satellite."

It smells like ozone hole (have you noticed that, once we have been forced
to change refrigerators, AC, and PCB wash, it mysteriously disappeared from
headlines?) or global warming.

a landfill is like a swamp, anything thrown in there is deprived of
oxygen, cellulose will last indefinately - see "bog oak"

Exactly. The alternative, incinerators, burns plastic bags equally well.
So, what's this distinction for? As usual, greens (which supported our
previous administration) do things they don't understand just for the sake
of doing something.

 

[Jasen Betts]

On 2011-01-02, F. Bertolazzi <TOGLIeset@MAIUSCOLEtdd.it> wrote:

Jasen Betts:

I don't think they found fragments of paper bags collected by ocean
currents - see "pacific garbage patch"

But also few plastic bags. Most of it is plastic bottles.

Since the rivers that flow into the Mediterranean bring less water than
what evaporates, there is a strong incoming current, so none of our garbage
can get out, it can only get in. Despite of that, and of the fact that
about 100 million people live in it's drainage basin, we have nothing like
it in our sea.

http://people.seas.harvard.edu/%7Erobinson/PAPERS/encycirc.pdf
page 9, figure 2

And probably neither you: "The size of the patch is unknown, as large items
readily visible from a boat deck are uncommon. Most debris consists of
small plastic particles suspended at or just below the surface, making it
impossible to detect by aircraft or satellite."

A unattributed quote from someone claiming ignorance is evidence of what
exactly?

It smells like ozone hole (have you noticed that, once we have been forced
to change refrigerators, AC, and PCB wash, it mysteriously disappeared from
headlines?) or global warming.

That's because the ozone layer shows signs of recovering, good news
doesn't sell papers,

a landfill is like a swamp, anything thrown in there is deprived of
oxygen, cellulose will last indefinately - see "bog oak"

Exactly. The alternative,

Do You think there is only one alternative, or is this a straw man?

Most opposition to plasic bags isn't about landfills anyway, it's
about pollution.

--
⚂⚃ 100% natural