Searching \ for '[PIC]: SMPS Transformer Calculus' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/power.htm?key=transformer
Search entire site for: 'SMPS Transformer Calculus'.

Exact match. Not showing close matches.
PICList Thread
'[PIC]: SMPS Transformer Calculus'
2001\09\16@094852 by Ing. Gustavo Quilosa

picon face
Hi everybody.
       Some have a "how to" calculate a SMPS forward transformer ??

thanks in advance,
   Gus




_________________________________________________________
Do You Yahoo!?
Get your free @yahoo.com address at http://mail.yahoo.com


--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.


2001\09\17@012430 by Bob Blick

face
flavicon
face
>        Some have a "how to" calculate a SMPS forward transformer ??

Hi Gus,

How about rules of thumb? I find them much more useful, perhaps because
manufacturer's data is required to do exact calculation and my hands-on
experience building SMPS's was as a hobby and using used or undocumented
cores. Now I still hack them together and later check my work with
manufacturer's data to make sure I'm not driving the core too hard. Heat
and efficiency will let you know how well you're doing.

A forward configuration(as an introduction to others who may be listening)
transfers when the transistor is ON, as opposed to flyback types which
store energy in the core and release it when the transistor turns OFF.

This configuration can have one transistor or more. Computer power supplies
are frequently of this type. Perhaps because the smallest core can be used
in a forward converter(because energy is not stored in it), and also the
transistors are exposed to the least voltage(because the flyback is clamped
the way they are connected in computer supplies).

The big drawback is that a substantial output inductor(before the first
output capacitor) is needed. In computer power supplies quite often this is
a toroid with all the outputs wound on it.

Another neat thing about forward converters is that the output voltage(or
rather the input-output transfer) is very linearly related to the turns
ratio and the duty cycle. These circuits rarely "freak out" because of core
saturation so they are easy to hack together without letting the smoke out
of the parts.

Usually I won't build a forward converter under 100 watts because the
smaller core size isn't a benefit, and the extra output inductor and
transistor or snubber makes it more complicated.

As a rule of thumb regarding turns-per-volt, find the right gauge of wire
for your primary and secondary, and wind it. When the core won't take any
more wire, you're done. Seriously.

Cheerful regards,

Bob Blick

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email spam_OUTlistservTakeThisOuTspammitvma.mit.edu with SET PICList DIGEST in the body


2001\09\17@030440 by Vasile Surducan

flavicon
face
Hi Gustavo,
try to find the folowing article:

"The switcher transformer: Designing it in one try for switching power
supplies"
by Phillip E. Thibodeau

in Electronic Design, september1 1980

Good things does not become older.

Vasile

On Sun, 16 Sep 2001, Ing. Gustavo Quilosa wrote:

{Quote hidden}

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email .....listservKILLspamspam@spam@mitvma.mit.edu with SET PICList DIGEST in the body


2001\09\17@073207 by Russell McMahon

picon face
> >        Some have a "how to" calculate a SMPS forward transformer ??

Old but useful -

Philips semiconductors used to publish VERY extensive documentation on all
types of switching power supplies.
I haven't looked recently but I imagine these will be available somewhere on
their site.

There is lopts of other stuff but for immediate relevance try -

-    "Transformer and choke design for forward-converter switched-mode power
supplies".
        EAB 33 no 3 pages 125 to 147 -

-    "Switched mode power supply transformer design nomograms"
       EAB 33 no 3

-    "Notes on SMPS transformer design nomograms"
      EAB 34 No 3 pp 123 - 136

Year unknown but rather old.
I think EAB is "Electronic Application Bulletin".



       Russell McMahon

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email listservspamKILLspammitvma.mit.edu with SET PICList DIGEST in the body


2001\09\17@101033 by Alan B. Pearce

face picon face
>There is lopts of other stuff but for immediate relevance try -
>
>-    "Transformer and choke design for forward-converter switched-mode
power
{Quote hidden}

I think I may have copies of these. If I remember correctly they were
published under the Mullard brand name in the 1970's, and the journal was
the Mullard equivalent of the HP Journal that Hewlett Packard used to
publish (do they still do so?).

The articles were published just as colour television was really taking off
in Europe, and this provided the mass market requirement for SMPS, and so a
lot of effort went into developing the cores and other components for them.

To find copies of these it is probably worth checking in a university
library, especially if there is a department involved with electronic
engineering around that time.

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email .....listservKILLspamspam.....mitvma.mit.edu with SET PICList DIGEST in the body


2001\09\17@103934 by Russell McMahon

picon face
{Quote hidden}

I actually have copies of the articles I cited - I can provide them (or the
most appropriate ones) via scanning and email if necessary but it would be
good iot those really interested did a web search to see if these or
something similar or newer was available.

Of course, they could 1st look at

_______________________________________

http://www.semiconductors.philips.com/products/all_appnotes.html

   ALL Philps app notes

________________________________________

OR

   http://www.smpstech.com/map.htm

   http://www.powersupplies.net/Design/design.htm

____________________________________________________

I'd guess this may about cover the requirement ... ?

   http://www.intusoft.com/psbook.htm

       Power Specialist's App Note Book
Papers on Simulation, Modeling and More

The papers cover a wide range of disciplines including: SMPS design,
Magnetics modeling, Signal Generator modeling, Power Electronics Device
Modeling, and Power Supply Testing.

The book can be downloaded in its entirety for free. Some of the papers, in
pdf format, can be downloaded individually as well. (See below)

Power Specialist's App Note Book Download in PDF format (3.2Meg Zip File) -
make sure to save the save to disk as "psbook.zip".


AND

_____________


Table of Contents
Power Specialists App Note Book

Switched Mode Power Supply Design
Average simulations of FLYBACK converters with SPICE3
A Tutorial Introduction to Simulating Current Mode Power Stages
Write your own generic SPICE Power Supplies controller models
Keep your Switch Mode Supply stable with a Critical-Mode Controller
Exploring SMPS Designs Using IsSpice
Average Models For Switching Converter Design
Simulating SMPS Designs
SSDI Diode Rectifier Models
High Efficiency Step-Down Converter
IsSpice4 Scripting Gives You More Power


Magnetics Design and Modeling
Designing a 12.5W 50kHz Flyback Transformer
Designing a 50W Forward Converter Transformer With Magnetics Designer


Signal Generators
IsSpice4 introduces a dead-time in your bridge simulations
Three Phase Generator
Simulating Pulse Code Modulation


Modeling For Power Electronics
A Spice Model For TRIACs
A Spice Model For IGBTs
SPICE 3 Models Constant Power Loads
Simulating Circuits With SCRs
Power Schottky and Soft Recovery Diodes
Spark Gap Modeling
SPICE Simulates A Fluorescent Lamp
Sidactor Modeling
Transformer and Saturable Core Modeling
Modeling Nonlinear Magnetics
Current Limited Power Supply
Macro Modeling Low Power DC-DC Converters
Modeling Non-Ideal Inductors in SPICE


Motor and Relay Modeling
Modeling A Relay
New SPICE Features Aid Motor Simulation


Test Program Development and Failure Analysis for SMPS
Automating Analog Test Design
Simulation measurements vs. Real world test equipment
New Techniques for Fault Diagnosis and Isolation of Switched Mode Power
Supplies
Application of Analog & Mixed Signal Simulation Techniques to the Synthesis
and Sequencing of Diagnostic Tests

Top

_________________________________________________________



http://www.electronics-tutorials.com/basics/switched-mode-power-supplies.htm

SWITCHED MODE POWER SUPPLIES

Add this valuable electronics tutorial site to your favorites!


______________________________________________________

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email EraseMElistservspam_OUTspamTakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body


More... (looser matching)
- Last day of these posts
- In 2001 , 2002 only
- Today
- New search...