[Q] 65W adaptor for notebook?

B

Bob J.

Guest
Hi, all,

I am an electrical engineer.

Now, I have a project to developing 65W adaptor for notebook under $6
included mechanical things; plug, cable, case, label, and other, for
instance.

In electrical, I have to make a schedule, however I have not had any
experience for it.

I really want to know what should I do now, how long it take for it,
how to calculate power stage, how to select topology, how to design
transformer, what is good reference to me, and others.

And also could you tell me it is good to me that Power Integrations and
PI Expert Suite v.6.0

Regards,

>From Bob.
 
"Bob J." wrote:

Hi, all,

I am an electrical engineer.

Now, I have a project to developing 65W adaptor for notebook under $6
included mechanical things; plug, cable, case, label, and other, for
instance.

In electrical, I have to make a schedule, however I have not had any
experience for it.

I really want to know what should I do now, how long it take for it,
how to calculate power stage, how to select topology, how to design
transformer, what is good reference to me, and others.
Click to expand...
If you haven't done it before then you have a problem clearly. It's quite
an 'art' to learn SMPS design from 'scratch'. When you've done it once, it
seems very easy the next time.

65W is clearly an example of where a flyback design makes the best sense.

Also pay strict attention to the safety requirements when designing a
transformer. Specifically pay atttention to *margins* and all other
clearance distances. It may be easier to use triple insulated wire - that's
what I do.

If you're unfamiliar with the requirements of safety standards you should
talk to someone who is.


And also could you tell me it is good to me that Power Integrations and
PI Expert Suite v.6.0
Click to expand...
I've used PI Expert. Mainly Version 4 actually. It's very good. You can
even use the derived ressults if you're not actually using their parts.

PI's aplication notes are also *excellent*. You should read most of them.
You'll find many of the answers you need right there.

Graham
 
"Bob J." wrote:

Hi, all,

I am an electrical engineer.

Now, I have a project to developing 65W adaptor for notebook under $6
included mechanical things; plug, cable, case, label, and other, for
instance.

In electrical, I have to make a schedule, however I have not had any
experience for it.

I really want to know what should I do now, how long it take for it,
how to calculate power stage, how to select topology, how to design
transformer, what is good reference to me, and others.

And also could you tell me it is good to me that Power Integrations and
PI Expert Suite v.6.0
Click to expand...
Also it might be a good idea since you're new to this, to purchase one of
PI's evaluation boards. They make several that are based on 'real world'
type applications. It may be possible to find one that's already close to
your requirements and adapt it accordingly.


Graham
 
Hi, all,

I am an electrical engineer.

===============================
Click to expand...

All that means, these days, is that after changing a faulty immersion
heater inside the domestic hot water tank you are qualified to
re-connect the two wires from the heating element to the power supply.

The manner in which you make your enquiry provides more information
about your status. It is THAT which contributes towards the quality of
the replies you get.

I wish you all the best with your project.
----
Reg
 
On 6 Aug 2005 23:44:05 -0700, "Bob J." <bob2a@hanmail.net> wroth:

Now, I have a project to developing 65W adaptor for notebook under $6
included mechanical things; plug, cable, case, label, and other, for
instance.

In electrical, I have to make a schedule, however I have not had any
experience for it.
Click to expand...
Buy as many different adapters as you can find that are close to your
requirements. Disassemble them, extract their circuits, and determine how much
it would cost you to reproduce them. Pick the most economical few and see if
you can re-design any parts of them to reduce the cost.

Each commercial adapter probably represents the work of at least four
designers each with an average of ten years of experience. If you find twenty
adapters to study, you will be privy to eight hundred man-years of design
expertise.

There should be no shame associated with this approach. Even Isaac
Newton said that his accomplishments were the result of "standing on the
shoulders of giants".

Jim
 
jmeyer@nowhere.net wrote:

On 6 Aug 2005 23:44:05 -0700, "Bob J." <bob2a@hanmail.net> wroth:


Now, I have a project to developing 65W adaptor for notebook under $6
included mechanical things; plug, cable, case, label, and other, for
instance.

In electrical, I have to make a schedule, however I have not had any
experience for it.


Buy as many different adapters as you can find that are close to your
requirements. Disassemble them, extract their circuits, and determine how much
it would cost you to reproduce them. Pick the most economical few and see if
you can re-design any parts of them to reduce the cost.

Each commercial adapter probably represents the work of at least four
designers each with an average of ten years of experience. If you find twenty
adapters to study, you will be privy to eight hundred man-years of design
expertise.

There should be no shame associated with this approach. Even Isaac
Newton said that his accomplishments were the result of "standing on the
shoulders of giants".
Click to expand...
Good point.

I assume the poster is in Asia somewhere. Or has access to Asian manufacturers.

There's *any number* of companies already making this stuff in volume. It's easy
for them to adapt a design to meet your spec and keep it low cost by using mainly
standardised parts inside.

Check out Skynet for example.

Skynet established in 1979 by Jim Liang in Taipei, Taiwan. Skynet specializes in
evaluation, designing and manufacturing linear, switching power supplies and
electronic ballast. With more than 25 years experiences, Skynet is proud to be the
leading power supplies provider in this industry. Skynet has one of the broadest
lines in the industry, ranging from 10W to 1000W. Skynet's facilities are certified
by ISO 9001, BABT and T-MARK.

Skynet's switching power supplies are based on state of the art technology with
strict attention to manufacturing quality. Skynet utilizes custom integrated
circuits, patent circuitry, extra long life capacitors and components, which result
in highly reliable, more efficient and compact power supplies. Skynet's power
supplies are also recognized and listed by UL, CSA, TUV, and VDE to assure top
quality and safety.

http://www.skynetusa.com/index.php?option=content&task=view&id=2&Itemid=26


Graham
 
Thank you for your advice, which is topology, safety, experience about
PI, and margins, clearance distances, and triple insulated wire in
transformer.

I have a book for SMPS, Switchmode Power Supply Handbook 2nd,
McGraw-Hill. It is difficult to me, however, could you recommend
another one to me.
 
Thanks a lot Jim. I am happy to know one of best method from you and
also good word about Newton, Sir Isaac.
 
Thank you, Graham for your another answer about Skynet again.

Bob.
 
I can do simulation tool and programming, Psim and Ascl and C language.
So, I wondering that it is necessary thing for developing adaptor about
65W that simulation before development.

If yes, what tool is good work?

Bob.
 
Buy doing this, be careful not to reproduce a patented design. I doubt
there are any in this field of work, but you never know...
 
"Bob J." <bob2a@hanmail.net> wrote in message
news:1123425082.551497.261070@g44g2000cwa.googlegroups.com...
Thank you for your advice, which is topology, safety, experience about
PI, and margins, clearance distances, and triple insulated wire in
transformer.

I have a book for SMPS, Switchmode Power Supply Handbook 2nd,
McGraw-Hill. It is difficult to me, however, could you recommend
another one to me.
Click to expand...
Unfortunately, It is about the best book there is.

You might find more specific information in application notes from suppliers
of ferrites and controller chips. A copy of the relevant safety standards is
very important too, to determine the proper layout.

Philips - which may now be "Ferroxcube" - had some very good design guides
on planar transformer design. <trying ...>Yup, it's ferroxcube now:
http://www.ferroxcube.com/appl/info/plandesi.pdf and
http://www.ferroxcube.com/appl/info/planconv.pdf
may be of use - there is more stuff on the site.

Planars are good for small-ish power supplies that need mains isolation and
are not supposed to cost anything. Well, I like them.
 
"Bob J." <bob2a@hanmail.net> wrote in message
news:1123397045.001805.132060@g47g2000cwa.googlegroups.com...
Hi, all,

I am an electrical engineer.

Now, I have a project to developing 65W adaptor for notebook under $6
included mechanical things; plug, cable, case, label, and other, for
instance.

In electrical, I have to make a schedule, however I have not had any
experience for it.
Click to expand...
Without experience, this will be hard to do.

You might as well consider CHEATING: Get quotes from a specialist
manufacturers of that kind of adapter and if they are less that $6, then buy
those - unless of course you are the guy the specialist manufacturer is
asking for quotes??
 
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