Boost Converter Efficiency Improvements - Page 8

Do you have a question? Post it now! No Registration Necessary

Translate This Thread From English to

Threaded View
Re: Boost Converter Efficiency Improvements
On Mon, 24 Jun 2013 07:15:15 -0700, the renowned Joerg

Quoted text here. Click to load it

I've run into that recently- the golden formula failed unit
consistency. 8-(  


Best regards,  
Spehro Pefhany
--  
"it's the network..."                          "The Journey is the reward"
snipped-for-privacy@interlog.com             Info for manufacturers: http://www.trexon.com
We've slightly trimmed the long signature. Click to see the full one.
Re: Boost Converter Efficiency Improvements
On Monday, 24 June 2013 02:29:18 UTC+10, Joerg  wrote:
Quoted text here. Click to load it

I've done so, but you are strangely unwilling to get hold of a copy of "Coa
xial AC Bridges" by Rayner and Kibble. Amazon offers two "new" and five use
d copies, and there might be one available in an academic library near you.
  
Quoted text here. Click to load it

It would probably be cheaper than buying the book - I've got the enamelled  
copper wire so I'd only have to buy the toroid.
  
Quoted text here. Click to load it

Not counting the Ayrton-Perry variable inductor, which I didn't know about  
when I wrote that.
  
Quoted text here. Click to load it

The search string Ayrton-Perry astatic inductor gave several hits, most of  
the them admittedly picking up the Ayrton-Perry variable inductor, which is
 something different again, Apparently it can also be made astatic

http://www.ebooksread.com/authors-eng/frank-malcolm-farmer/electrical-measu
rements-in-practice-hci/page-22-electrical-measurements-in-practice-hci.sht
ml

The Wiley Survey of Instrumentation and Measurement by Stephen A. Dyer has  
drawing at figure 5(b) on page 351 which seems to be a version of the Ayrto
n-Perry inductor, though it's not identified as such.

http://books.google.com.au/books?id=Wr6l42rEizUC&pg=PA351&lpg=PA351&d
q=Ayrton-Perry+astatic+inductor&source=bl&ots=xnCt913v20&sig=aiBLe4
FeH7FYV-H-1uR82upbV30&hl=en&sa=X&ei=hp_HUcW3GIb8iAf1s4GwDg&ved0C%C4
Q6AEwAA#v=onepage&q=Ayrton-Perry%20astatic%20inductor&f=false

--  
Bill Sloman, Sydney

Re: Boost Converter Efficiency Improvements
Bill Sloman wrote:
Quoted text here. Click to load it


Then post it. As a drawing or alink with a drawing, like is customary here.


Quoted text here. Click to load it

Yeah, right, you cannot prove your point and so you want to make others
buy a book. That has about the same quality as saying "Well, then search
the web for it yourself".

Books are full of misnomers (and more gross errors as well), one lone
book proves nothing. Ayrton and Perry would most certainly have
published or patented an "inductanceless inductor" if it existed. But it
doesn't exist.


Quoted text here. Click to load it

You only need a pencil, a sheet of paper and a scanner.

[...]


Quoted text here. Click to load it
http://www.ebooksread.com/authors-eng/frank-malcolm-farmer/electrical-measurements-in-practice-hci/page-22-electrical-measurements-in-practice-hci.shtml
Quoted text here. Click to load it
http://books.google.com.au/books?id=Wr6l42rEizUC&pg=PA351&lpg=PA351&dq=Ayrton-Perry+astatic+inductor&source=bl&ots=xnCt913v20&sig=aiBLe4FeH7FYV-H-1uR82upbV30&hl=en&sa=X&ei=hp_HUcW3GIb8iAf1s4GwDg&ved0C%C4Q6AEwAA#v=onepage&q=Ayrton-Perry%20astatic%20inductor&f=false
Quoted text here. Click to load it

"Restricted: You have reached your viewing limit of this book"

Great. Anyhow, the trackback or bootlace winding technique, if that's
what you mean, has nothing to do with the Ayrton Perry winding
technique. It will not cancel the inductance, which would not make much
sense in an inductor in the first place anyhow.

--  
Regards, Joerg

http://www.analogconsultants.com/

Re: Boost Converter Efficiency Improvements
On Tuesday, 25 June 2013 00:09:49 UTC+10, Joerg  wrote:
Quoted text here. Click to load it
re.

No need now ...
  
Quoted text here. Click to load it
  
Quoted text here. Click to load it
  
Quoted text here. Click to load it
  
Quoted text here. Click to load it
  
Quoted text here. Click to load it
  
Quoted text here. Click to load it

I don't even need that - John Devereux did it for me.
  
Quoted text here. Click to load it
easurements-in-practice-hci/page-22-electrical-measurements-in-practice-hci
.shtml
Quoted text here. Click to load it
51&dq=Ayrton-Perry+astatic+inductor&source=bl&ots=xnCt913v20&sig=ai
BLe4FeH7FYV-H-1uR82upbV30&hl=en&sa=X&ei=hp_HUcW3GIb8iAf1s4GwDg&ved=
0CC4Q6AEwAA#v=onepage&q=Ayrton-Perry%20astatic%20inductor&f=false  
Quoted text here. Click to load it

Sure, but it included the drawing that you were so mad keen to see.

Quoted text here. Click to load it

As I've repeatedly said, you are confusing the Ayrton-Perry non-inductive r
esistor with the Ayrton-Perry astatic inductor - two different components i
nvented by the same two people. Why not go for broke and confuse both devic
es with the Ayrton-Perry variable inductor, invented by the same fecund pai
r?

That way you could make jokes about a variable non-inductive inductor ...

--  
Bill Sloman, Sydney



Re: Boost Converter Efficiency Improvements
Bill Sloman wrote:
Quoted text here. Click to load it

[...]


Quoted text here. Click to load it

That example is not the Ayrton-Perry winding. It's the simple loop-back
done on toroids to reduce an external field, nothing special about that.

[...]


--  
Regards, Joerg

http://www.analogconsultants.com/

Re: Boost Converter Efficiency Improvements
On Wednesday, 26 June 2013 10:48:11 UTC+10, Joerg  wrote:
Quoted text here. Click to load it
  
Quoted text here. Click to load it
  
Quoted text here. Click to load it

But Aryton and Perry were apparently the first to discover this "simple" tr
ick, along with the astatic resistor winding also - separately - credited t
o them, and people who know a bit about what electronics was being done in  
the UK around 1900 have labelled it as theirs.

If you want to pose as an expert on the period, do try, but even a dilettan
te like me will probably show you up embarrassingly fast.

It's not the simplest loop-back that minimises the external field, which is
 just a single turn in the plane of the toroid, as mentioned by Rayner and  
Kibble who go on to describe a slightly more complicated winding scheme whi
ch they find even better than the Ayrton-Perry "bootlace" for some applicat
ions - less inter-winding capacitance.

--  
Bill Sloman, Sydney


Re: Boost Converter Efficiency Improvements
Bill Sloman wrote:
Quoted text here. Click to load it

The bifilar trick is much older than 1900. Some reading material:

http://www.teslauniverse.com/nikola-tesla-patents-512,340-coil-for-electro-magnets

And why do you think Ayrton and Perry did not publish this if they'd
invented it? They did invent the non-inductive winding and published
that, so there cannot be any excuse about a scarcity of ink or a paper
shortage.

--  
Regards, Joerg

http://www.analogconsultants.com/

Re: Boost Converter Efficiency Improvements
On Thu, 27 Jun 2013 10:16:22 -0400, Phil Hobbs

Quoted text here. Click to load it

I assume you mean .org, not .com?

Jon

Re: Boost Converter Efficiency Improvements
On 6/27/2013 6:38 PM, Jon Kirwan wrote:
Quoted text here. Click to load it
Roight.  Something like that.

Cheers

Phil Hobbs

--  
Dr Philip C D Hobbs
Principal Consultant
We've slightly trimmed the long signature. Click to see the full one.
Re: Boost Converter Efficiency Improvements
On Friday, June 21, 2013 4:26:25 AM UTC+2, Bill Sloman wrote:
Quoted text here. Click to load it
some prototype coils wound at
Quoted text here. Click to load it
 
Quoted text here. Click to load it
cottage coil-winder but it didn't look like a huge place when I dropped in to
deliver my formers and winding specifications. Horst is no metropolis.
Quoted text here. Click to load it
NRE, or a huge minimum order. I save a bit by putting on the double screening
myself - it's a bit fiddly, and doesn't exactly need a coil winding machine.
Quoted text here. Click to load it

The SRF0703 can be bought for 20cents. No way you can order custom samples at
that price range unless you are asking for +10k lot size.

Regards

Klaus


Re: Boost Converter Efficiency Improvements
On Saturday, 22 June 2013 04:08:39 UTC+10, Klaus Kragelund  wrote:
Quoted text here. Click to load it

<snip>
  
Quoted text here. Click to load it
that price range unless you are asking for +10k lot size.

Not in Australia

http://au.mouser.com/ProductDetail/Bourns/SRF0703-220M/?qs=Q2Pzc27CV9t4dB0OUyjU5w==

$A 1.19 for 1 to 49. Even for 6,000 it's only down to $A 0.473
  
And it's only cheap if it does exactly what you want, which doesn't happen
often. If you have to add extra components to make it work in your application,
it becomes a lot less attractive.

--  
Bill Sloman, Sydney

Re: Boost Converter Efficiency Improvements
Bill Sloman wrote:
Quoted text here. Click to load it
http://au.mouser.com/ProductDetail/Bourns/SRF0703-220M/?qs=Q2Pzc27CV9t4dB0OUyjU5w==
Quoted text here. Click to load it

US$ 0.33 over yonder in the Wild West:

http://www.digikey.com/product-detail/en/SRF0703-330M/SRF0703-330MTR-ND/2458500


Quoted text here. Click to load it

I am not sure what you are doing but somehow that tends not to happen in
my designs :-)

--  
Regards, Joerg

http://www.analogconsultants.com/

Re: Boost Converter Efficiency Improvements
On Saturday, 22 June 2013 11:05:48 UTC+10, Joerg  wrote:
Quoted text here. Click to load it
http://au.mouser.com/ProductDetail/Bourns/SRF0703-220M/?qs=Q2Pzc27CV9t4dB0OUyjU5w==
 
Quoted text here. Click to load it
http://www.digikey.com/product-detail/en/SRF0703-330M/SRF0703-330MTR-ND/2458500

For a 6000 unit reel. It's still $0.75 for 1-9, and a lot more than $0.20

Quoted text here. Click to load it

I've often found auxiliary windings to be handy.

Sensing the voltage generated across one coil while driving the magnetising
current through another is sometimes a useful trick.

--  
Bill Sloman, Sydney

Re: Boost Converter Efficiency Improvements
On Saturday, June 22, 2013 3:05:48 AM UTC+2, Joerg wrote:
Quoted text here. Click to load it
http://au.mouser.com/ProductDetail/Bourns/SRF0703-220M/?qs=Q2Pzc27CV9t4dB0OUyjU5w==
Quoted text here. Click to load it
http://www.digikey.com/product-detail/en/SRF0703-330M/SRF0703-330MTR-ND/2458500
Quoted text here. Click to load it

And multiply with 60% which is the rule of thumb of the price reduction you get
when negotiating price with the distributor instead of the mouser/digikey
equivalents

Cheers

Klaus

Re: Boost Converter Efficiency Improvements
Klaus Kragelund wrote:
Quoted text here. Click to load it

[...]


Quoted text here. Click to load it
http://au.mouser.com/ProductDetail/Bourns/SRF0703-220M/?qs=Q2Pzc27CV9t4dB0OUyjU5w==
Quoted text here. Click to load it
http://www.digikey.com/product-detail/en/SRF0703-330M/SRF0703-330MTR-ND/2458500
Quoted text here. Click to load it

Or use 40% for Asian pricing, and maybe 35% in China :-)

--  
Regards, Joerg

http://www.analogconsultants.com/

Re: Boost Converter Efficiency Improvements
On Tue, 18 Jun 2013 17:57:11 -0700, Joerg wrote:

Quoted text here. Click to load it

:-)

--  
"For a successful technology, reality must take precedence  
over public relations, for nature cannot be fooled."
We've slightly trimmed the long signature. Click to see the full one.
Re: Boost Converter Efficiency Improvements
Fred Abse wrote:
Quoted text here. Click to load it

Whoops :-)

What I meant is the song "Highway to Hell" by AC/DC.

--  
Regards, Joerg

http://www.analogconsultants.com/

Re: Boost Converter Efficiency Improvements
On Sunday, 16 June 2013 03:31:50 UTC+10, David Jordan  wrote:
Quoted text here. Click to load it

<SNIP>
  
Quoted text here. Click to load it

If you'd been up to winding your own transformer and probably the inductor  
as well, a Baxandall class-D oscillator with an 11:1 step-up ratio would ha
ve given you your 200V from 12V.

The peak voltage across the switching MOSFETs would have been pi/2 times 12
V - 19V - so you could have used the opposite ends of teh primnary widings  
to drive the MOSFET gates.

You would have got a bit over 90% efficiency,and the peak primary current w
ould have been around 400mA. Your inductor would have to be wound to cope w
ith that current. If you did use MOSFET switches, the oscillator probably w
ouldn't squeg, no matter how big you made your filter inductance.

RF emissions wouldn't be too bad - the Baxandall oscillator does generate o
dd harmonics, but at relatively low levels. The MOSFETs would be switching  
on and off at relatively low current levels - way below the peak 400mA circ
ulating in the primary. The rectifiers required to get the 200V DC out of t
he secondary would be a bit fiercer, but a ferrite bead between them and th
e high voltage reservoir capacitor would probably take out any fast edges.

You obviously aren't going to build one, but ti probably would have been a  
nicer solution, if you had access to a coil-winding machine with a turns co
unting dial.

--  
Bill Sloman, Sydney

Re: Boost Converter Efficiency Improvements
On Sat, 15 Jun 2013 18:31:50 +0100, David Jordan

Quoted text here. Click to load it

There is a theoretical disadvantage to the dual-winding inductor
thing: the windings are identical so the copper in the boost winding
is too thick relative to the driven winding. So the copper use is not
quite optimized. That's a small price to pay for using a cheap stock
part.



Re: Boost Converter Efficiency Improvements
On Monday, 17 June 2013 01:37:03 UTC+10, John Larkin  wrote:
Quoted text here. Click to load it
  
<snip>

Quoted text here. Click to load it

What is the actual price differential between the cheap stock part, and an  
more nearly optimal one that you might have gone to the trouble of designin
g and getting wound?

My impression was that most of the cost of small ferrite-cored transformers
 was in the copper and the ferrite - the labour required to wind the copper
 onto a former wasn't all that expensive, and automating that part of the j
ob didn't usually save enough to pay for - usually - unnecessarily generous
 copper and core in the off-the-shelf part.

--  
Bill Sloman, Sydney

Site Timeline