SMPS Transformer Turns Equations Help

[venki]

Hi,

I am planning to make an SMPS for my new ampilfier. It requires a power supply of +-20 V 10A (rms). I would like to know the equations for Calculating
1. the number of turns in primary/Secondary

2. the guage of wire to be used.

I intend to use 230V ac (rectified) as input. It would be of great help if somebody could post the equations.

Thanks in Advance,

Venki.😀

 

[poobah]

This application note applies to a specific part... which would not work for you... but it is still a good collection of data & formulas.

You will be looking for a "buck" or "forward" convertor.

link

😉

 

[N-Channel]

Turns Ratio

Venki,

Here is a laundry-list of books I regularly recommend to members asking questions about SMPS design in general, or specific ones about the different sections of a Switcher:

1) High Frequency Switching Power Supply Design - Geo. Chryssis (c) 1989 (Don't know ISBN) 😕

2) Power Supply Cookbook (EDN Series for Design Engineers)
by Marty Brown; 2nd edition May 2001 ISBN: 075067329X

3) Switchmode Power Supply Design - Abraham I. Pressman (Don't know year or ISBN) 😕

Chryssis' book is, perhaps the best on transformer design. He includes design procedures for both Forward and Flyback topologies. I have used his procedure to design many SMPSs with great success! 😎

Hope this helps!

Steve 😀 😎

 

[cerrem]

Hi Venki.....
I believe I Emailed you a few weeks ago regarding this design...
I need much more info.....
What is the input voltage range for this switcher....
I recomend a Push-Pull converter in current mode...


Chris

 

[jackinnj]

got Excel?

here's a link to a spreadsheet I cobbled for push-pull converters -- works pretty well with the Linear Tech series of switching chips so it should work with others: http://www.tech-diy.com/smps_xfmr.xls