Driver to drive?

[miso]

This chip doesn't provide isolation. I'd think twice about using it if
you are not familiar with electronics design.

The chip provides a 7.5v output which presumably you could use to power
up PWM circuitry, but I don't know if I would trust bringing the PWM
control to the outside world due to a lack of isolation.

If you are just experimenting, why not get a surplus 48vdc switcher,
then use a DC/DC to drive the LEDs.

If you are trying to develop a product to sell on the open market, I
think this is over your head.

 

[Joerg]

sridhar09.cherukuri@gmail.com wrote:

Pics of the the two inductor samples I received.

https://picasaweb.google.com/109531737128214970189/Design?authuser=0&authkey=Gv1sRgCM2zl5P8o-jqPw&feat=directlink


Both are 1.8mH in value. The one with blue core uses Epcos core and
has high permeability of around 4300 and Al value of around 9740nH.
It has 13 turns to achieve 1.8mH. outer dia is 20mm and inner dia is
10mm.

These inductors require to handle current of max 5A at 16V. If I use
the one with blue color core due to its small size, will it be able
to operate at 5A without saturating?

Looking at the no of turns on the bigger one it appears to have low
permeability and Al values.

Which is more suitable for operation at 5A at 16V in terms of core
saturation?

Core saturation can be easily measured via a shunt resistor and scope.
But core saturation is not the whole game, core and winding losses (skin
effect etc.) are the other. Core losses can be vastly different between
the various materials. Can be measured, for example via temperature rise.

I couldn't get any more details from the supplier.

Then I would switch suppliers. Seriously.

--
Regards, Joerg

http://www.analogconsultants.com/

 

[Tim Williams]

What does the other core look like under that pile of wire? Is it yellow
and white by any chance?

The blue one will saturate around 0.5 to 1A. Ferrite must be gapped in
order to store any useful energy.

Tim

--
Deep Friar: a very philosophical monk.
Website: http://seventransistorlabs.com

<sridhar09.cherukuri@gmail.com> wrote in message
news:dd82a579-a603-4a3a-b019-48404917f10b@googlegroups.com...

Pics of the the two inductor samples I received.

https://picasaweb.google.com/109531737128214970189/Design?authuser=0&authkey=Gv1sRgCM2zl5P8o-jqPw&feat=directlink

Both are 1.8mH in value. The one with blue core uses Epcos core and has
high permeability of around 4300 and Al value of around 9740nH. It has
13 turns to achieve 1.8mH. outer dia is 20mm and inner dia is 10mm.

These inductors require to handle current of max 5A at 16V. If I use the
one with blue color core due to its small size, will it be able to
operate at 5A without saturating?

Looking at the no of turns on the bigger one it appears to have low
permeability and Al values.

Which is more suitable for operation at 5A at 16V in terms of core
saturation?

I couldn't get any more details from the supplier.

Thanks
Sridhar

 

[Bill Sloman]

On 14 Dec, 04:59, Joerg <inva...@invalid.invalid> wrote:

sridhar09.cheruk...@gmail.com wrote:
Pics of the the two inductor samples I received.

https://picasaweb.google.com/109531737128214970189/Design?authuser=0&...

Both are 1.8mH in value. The one with blue core uses Epcos core and
has high permeability of around 4300 and Al value of around 9740nH.
It has 13 turns to achieve 1.8mH. outer dia is 20mm and inner dia is
10mm.

These inductors require to handle current of max 5A at 16V. If I use
the one with blue color core due to its small size, will it be able
to operate at 5A without saturating?

Looking at the no of turns on the bigger one it appears to have low
permeability and Al values.

Which is more suitable for operation at 5A at 16V in terms of core
saturation?

Core saturation can be easily measured via a shunt resistor and scope.
But core saturation is not the whole game, core and winding losses (skin
effect etc.) are the other. Core losses can be vastly different between
the various materials. Can be measured, for example via temperature rise.

I couldn't get any more details from the supplier.

Then I would switch suppliers. Seriously.

You don't get detailed information about cores from suppliers but from
manufacturers. The EPCOS web-site will tell you everything you need to
know about the EPCOS core if you've got it's EPCOS part number.

I'd be a bit cautious about a supplier who didn't know enough to refer
a customer to the relevant manufacturer's web site, but stocking
ferrite cores doesn't seem to be a business where the broad-line
suppliers can make money, so you end up buying small quantities of odd
ferrites from niche businesses.

I've just found a hole in my files - I bought a "low distortion"
ferrite core Ferroxcube EP13-3E55-A100 from a small and specialised
distributor in Germany last year, but I had to dig the number off a
back-up DVD, and the e-mail file that gives the name of the place
hasn't come off it's back-up (though it may be hidden behind some
cached data).

--
Bill Sloman, Sydney

 

[Robert Baer]

sridhar09.cherukuri@gmail.com wrote:

Pics of the the two inductor samples I received.

https://picasaweb.google.com/109531737128214970189/Design?authuser=0&authkey=Gv1sRgCM2zl5P8o-jqPw&feat=directlink

Both are 1.8mH in value. The one with blue core uses Epcos core and has high permeability of around 4300 and Al value of around 9740nH. It has 13 turns to achieve 1.8mH. outer dia is 20mm and inner dia is 10mm.

These inductors require to handle current of max 5A at 16V. If I use the one with blue color core due to its small size, will it be able to operate at 5A without saturating?

Looking at the no of turns on the bigger one it appears to have low permeability and Al values.

Which is more suitable for operation at 5A at 16V in terms of core saturation?

I couldn't get any more details from the supplier.

Thanks
Sridhar


Since you have both in hand,you can easily test them for saturation.

Use a current transformer, or a very low value resistor in series for
current sensing.
Use a step voltage drive; before saturation the current will look
like a linear ramp; saturation is indicated by what looks line
exponential current increase. The faster the transition, the closer the
closer is to a square-loop material.

 

On Friday, December 14, 2012 5:24:38 AM UTC+5:30, Bill Sloman wrote:

On 14 Dec, 04:59, Joerg <inva...@invalid.invalid> wrote:

sridhar09.cheruk...@gmail.com wrote:

Pics of the the two inductor samples I received.



https://picasaweb.google.com/109531737128214970189/Design?authuser=0&...



Both are 1.8mH in value. The one with blue core uses Epcos core and

has high permeability of around 4300 and Al value of around 9740nH.

It has 13 turns to achieve 1.8mH. outer dia is 20mm and inner dia is

10mm.



These inductors require to handle current of max 5A at 16V. If I use

the one with blue color core due to its small size, will it be able

to operate at 5A without saturating?



Looking at the no of turns on the bigger one it appears to have low

permeability and Al values.



Which is more suitable for operation at 5A at 16V in terms of core

saturation?



Core saturation can be easily measured via a shunt resistor and scope.

But core saturation is not the whole game, core and winding losses (skin

effect etc.) are the other. Core losses can be vastly different between

the various materials. Can be measured, for example via temperature rise.



I couldn't get any more details from the supplier.



Then I would switch suppliers. Seriously.



You don't get detailed information about cores from suppliers but from

manufacturers. The EPCOS web-site will tell you everything you need to

know about the EPCOS core if you've got it's EPCOS part number.



I'd be a bit cautious about a supplier who didn't know enough to refer

a customer to the relevant manufacturer's web site, but stocking

ferrite cores doesn't seem to be a business where the broad-line

suppliers can make money, so you end up buying small quantities of odd

ferrites from niche businesses.



I've just found a hole in my files - I bought a "low distortion"

ferrite core Ferroxcube EP13-3E55-A100 from a small and specialised

distributor in Germany last year, but I had to dig the number off a

back-up DVD, and the e-mail file that gives the name of the place

hasn't come off it's back-up (though it may be hidden behind some

cached data).



--

Bill Sloman, Sydney

The one with pile of copper wire, has geryish black or carbon color core.

-Sridhar

 

[mook johnson]

On 12/13/2012 12:12 PM, Tim Williams wrote:

What does the other core look like under that pile of wire? Is it yellow
and white by any chance?

The blue one will saturate around 0.5 to 1A. Ferrite must be gapped in
order to store any useful energy.

Tim

Agreed,

An ungapped high perm core will will not tolerate DC well before
saturation. At best the inductance will "swing" like crazy.

 

[rickman]

On 12/18/2012 11:45 AM, rickman wrote:

Given the title, what is the SNR of this newsgroup? How does it compare
to the SNR of the technical groups in the general newsgroup community?

Or should I more usefully be asking about the SINAD?

Rick

Actually, I meant to post this to s.e.d, but the s.e.c group gets a lot
of the same noise.

Rick

 

[Phil Hobbs]

On 12/18/2012 12:41 PM, rickman wrote:

On 12/18/2012 11:45 AM, rickman wrote:
Given the title, what is the SNR of this newsgroup? How does it compare
to the SNR of the technical groups in the general newsgroup community?

Or should I more usefully be asking about the SINAD?

Rick

Actually, I meant to post this to s.e.d, but the s.e.c group gets a lot
of the same noise.

Rick

It's actually very high. The low level ankle biting is dwarfed by the
occasional peak of brilliance, since power goes as amplitude squared.

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

 

[rickman]

On 12/18/2012 3:46 PM, Phil Hobbs wrote:

On 12/18/2012 12:41 PM, rickman wrote:
On 12/18/2012 11:45 AM, rickman wrote:
Given the title, what is the SNR of this newsgroup? How does it compare
to the SNR of the technical groups in the general newsgroup community?

Or should I more usefully be asking about the SINAD?

Rick

Actually, I meant to post this to s.e.d, but the s.e.c group gets a lot
of the same noise.

Rick

It's actually very high. The low level ankle biting is dwarfed by the
occasional peak of brilliance, since power goes as amplitude squared.

Really? Care to point me to some of those high power peaks? The ultra
low duty cycle might keep the SINAD pretty low after all, but I haven't
been here long. Maybe you are talking about stuff that is of the
magnitude of a supernova.

Rick

 

[mpm]

On Tuesday, December 18, 2012 4:57:35 PM UTC-5, rickman wrote:

On 12/18/2012 3:46 PM, Phil Hobbs wrote:

On 12/18/2012 12:41 PM, rickman wrote:

On 12/18/2012 11:45 AM, rickman wrote:

Given the title, what is the SNR of this newsgroup? How does it compare

to the SNR of the technical groups in the general newsgroup community?



Or should I more usefully be asking about the SINAD?



Rick



Actually, I meant to post this to s.e.d, but the s.e.c group gets a lot

of the same noise.



Rick



It's actually very high. The low level ankle biting is dwarfed by the

occasional peak of brilliance, since power goes as amplitude squared.





Really? Care to point me to some of those high power peaks? The ultra

low duty cycle might keep the SINAD pretty low after all, but I haven't

been here long. Maybe you are talking about stuff that is of the

magnitude of a supernova.



Rick

It's all digital these days, so SINAD isn't all that useful a quantity.
Time to think in terms of "Delivered Audio Quality" and what not.
Feel free to substitute your own keyword for "Audio".

But yes, there is a lot of noise lately, digital or otherwise.

And I don't know what measure came before SINAD, but whatever that was, that's what JT contributes, given his advanced age and all..

 

[Michael A. Terrell]

Charles wrote:

AGW is only one method by which the presumed most intelligent species of
this lonely planet will succeed in destroying the habitat and themselves.

Another worth your consideration is the strong resistance to liberal
democracy among many mid-east folks.

Yet another is the extreme polarization between economic classes in, the
gold standard of social equity, the U.S.A.

Does not look so hot ... should ameliorate warming :&gt

Anyone with at least half a brain, resists all of you liberal idiots.

 

[benj]

On Thu, 20 Dec 2012 18:59:24 -0800, Bill Sloman wrote:

Actually, Matt Ridley is a scientist, but a zoologist, and - like most
of the "scientists" active in the denialist propaganda machine - rather
prone to post total nonsense on anthropogenic global warming.

Actually it is the science denier alarmists that are prone to total
nonsense. They don't even bother to read their own links or examine their
own data.

This sure looks like Global Tepid to me:

http://www.mrk-inc.com/users/bspam/AGWGISSOCT.gif

I keep waiting for that accelerating and dramatic temperature rise that
we keep being told is going on, but so far for the past decade nada.

So are you going to say that Dr. Hansen is not a scientist? I might agree
with you on that one...

 

[Bill Sloman]

On 21 Dec, 12:52, John Larkin <jlar...@highlandtechnology.com> wrote:

On Thu, 20 Dec 2012 17:17:05 -0800 (PST), RichD

r_delaney2...@yahoo.com> wrote:
Perhaps there will be warming, but not overheating:

http://tinyurl.com/wsj-ridley-on-GW

1.6* C seems survivable, maybe even benign.

More CO2, a bit warmer and wetter, great for crops. Add fracking and
various technologies, and genetic breakthroughs, and we have a Golden
Age.

It does take a Pollyanna level of optimistic ignorance to be that
unrealistic , but John isn't short of incorrigible ignorance.

More CO2, quite a bit warmer and wetter is places that didn't used to
be wet before may be good for plants, but it's more likely to be good
for weeds than for the crops which we've selected and bred to do well
in the climate we've had for the past ten thousand years or so, in the
places where those crops have always grown well up to now.

Ridley isn't a scientist, but he does cite credible
sources.

But does he cite them correctly? Monkton published a plausible-looking
piece in the US Institute of Physics "Physics Today" but a detailed
follow-up found some 128 howlers (and I suspect that the critic lost
interest at 2^7, rather than running out of mistakes to identify).

http://www.sourcewatch.org/index.php?title=Christopher_Monckton

Of course, we know Sam Wormley will give this
due consideration, famous as he is for rationality
and objectivity and erudition, immune to hysteria
and ego and emotional investment.

PS  Epigram from the article: "... given the IPCC's
record of replacing evidence-based policy-making
with policy-based evidence-making..."

Good line.

Hilarious in the circumstances, but John Larkin doesn't know enough to
notice.

There are still people claiming that the entire human species will be
eliminated by AGW.

Really? We could certainly engineer a population crash, and the
survivors wouldn't be well placed to sustain a modern industrialised
society, but extinction isn't all that likely. One argument is that
language based cultural learning was our trick to adapt to the
relatively rapid cycling between ice-ages and interglacials that has
been going on since we split off from the chimpanzees, and it should
leave us well placed to cope with a comparably abrupt warming.

--
Bill Sloman, Sydney

 

[Unum]

On 12/20/2012 9:40 PM, benj wrote:

On Thu, 20 Dec 2012 18:59:24 -0800, Bill Sloman wrote:

Actually, Matt Ridley is a scientist, but a zoologist, and - like most
of the "scientists" active in the denialist propaganda machine - rather
prone to post total nonsense on anthropogenic global warming.

Actually it is the science denier alarmists that are prone to total
nonsense. They don't even bother to read their own links or examine their
own data.

This sure looks like Global Tepid to me:

http://www.mrk-inc.com/users/bspam/AGWGISSOCT.gif

I keep waiting for that accelerating and dramatic temperature rise that
we keep being told is going on, but so far for the past decade nada.

So are you going to say that Dr. Hansen is not a scientist? I might agree
with you on that one...

Why don't we just use a graph straight from NASA;

http://data.giss.nasa.gov/gistemp/graphs_v3/Fig.A2.pdf

 

[Bill Sloman]

On 21 Dec, 12:17, RichD <r_delaney2...@yahoo.com> wrote:

Perhaps there will be warming, but not overheating:

http://tinyurl.com/wsj-ridley-on-GW

1.6* C seems survivable, maybe even benign.
Ridley isn't a scientist, but he does cite credible
sources.

Of course, we know Sam Wormley will give this
due consideration, famous as he is for rationality
and objectivity and erudition, immune to hysteria
and ego and emotional investment.

PS  Epigram from the article: "... given the IPCC's
record of replacing evidence-based policy-making
with policy-based evidence-making..."

Actually, Matt Ridley is a scientist, but a zoologist, and - like most
of the "scientists" active in the denialist propaganda machine -
rather prone to post total nonsense on anthropogenic global warming.

http://www.sourcewatch.org/index.php/Matt_Ridley

This is just "The Wall Street Journal" doing it's usual service to the
denialist propaganda machine.

--
Bill Sloman, Sydney

 

[1treePetrifiedForestLane]

"global" warming is really nothing but a grotesque 100-year-old
nonsequiter
of glass "house" effects, as is seen by using spherical trig and
Snell's law (for putative changes in albedo). Ahrrenius did not
get teh first Nobel in chemistry for that ****.

you will probably have to use "geometrical optics," that is to say,
one normal "ray" to the wavefront from Sun, but
that doesn't make Newton's "theory," a theory!

for weeds than for the crops which we've selected and bred to do well
in the climate we've had for the past ten thousand years or so, in the

 

[1treePetrifiedForestLane]

actually, as far as I've seen,
they publish just as much Confirmerist stuff, because
that is just the nature of the market. in particular,
although the so-called Republicans might aver that
my Congressman's old ('91) cap-and-trade bill was
just a "tax on SOx and NOx," it is really just "free-er trade;"
perhaps that is why this mandatory program was passed
unanimously by both houses.

> Given the Wall Street Journal's enthusiasm for publishing denialist

 

[Mickey Langan]

On 2012-12-21, Bill Sloman <bill.sloman@ieee.org> wrote:

On 21 Dec, 12:17, RichD <r_delaney2...@yahoo.com> wrote:
Perhaps there will be warming, but not overheating:

http://tinyurl.com/wsj-ridley-on-GW

1.6* C seems survivable, maybe even benign.
Ridley isn't a scientist, but he does cite credible
sources.

Of course, we know Sam Wormley will give this
due consideration, famous as he is for rationality
and objectivity and erudition, immune to hysteria
and ego and emotional investment.

PS ?Epigram from the article: "... given the IPCC's
record of replacing evidence-based policy-making
with policy-based evidence-making..."

Given the Wall Street Journal's enthusiasm for publishing denialist
propaganada,

You can't even make it a sentence without an ad-hominem. Is it
any wonder that global warming proponents have completely lost
the PR battle?

--
Mickey

Why is it more moral for a federal bureaucrat in a state-supplied SUV to
shut down an offshore oil rig on grounds that it is too dangerous for
the environment than for a private individual to risk his own capital to
find some sort of new fuel to power his government's SUV fleet?
-- Victor Davis Hanson

 

[Bill Sloman]

On 21 Dec, 14:00, 1treePetrifiedForestLane <Space...@hotmail.com>
wrote:

"global" warming is really nothing but a grotesque 100-year-old
nonsequiter
of glass "house" effects, as is seen by using spherical trig and
Snell's law (for putative changes in albedo).  Ahrrenius did not
get the first Nobel in chemistry for that ****.

http://www.aip.org/history/climate/index.htm

gives the story in rather more detail, and with a rather better grasp
of physics.

<snipped incoherent rubbish>

--
Bill Sloman, Sydney