## Calculating Transformer Core Area

## Calculating Transformer Core Area

(OP)

Hello,

My application requires the use of a custom transformer and I want to calculate the theoretical minimum core cross sectional area that will be needed in order to achieve my power output ratings. The input voltage will be standard 120VAC and the output will be 5VAC at 500mA. I would like to know the minimum core cross sectional area for both a toroidal transformer as well as a core type and shell type transformer. Any help or equations would be greatly appreciated!

Thanks,

M

My application requires the use of a custom transformer and I want to calculate the theoretical minimum core cross sectional area that will be needed in order to achieve my power output ratings. The input voltage will be standard 120VAC and the output will be 5VAC at 500mA. I would like to know the minimum core cross sectional area for both a toroidal transformer as well as a core type and shell type transformer. Any help or equations would be greatly appreciated!

Thanks,

M

## RE: Calculating Transformer Core Area

Dan - Owner

http://www.Hi-TecDesigns.com

## RE: Calculating Transformer Core Area

## RE: Calculating Transformer Core Area

## RE: Calculating Transformer Core Area

Earlier editions of McLyman's books can be found as pdf on the internet (he worked for JPL and designed power supplies for space probes, so early editions were in the public domain). Also, you can go to www.coremaster.com and look at their application notes (written by McLyman). Coremaster makes a more exotic nanocrystalline core, so depending upon your end application their offerings may not be what you need, but his approach is there in full detail and you can use the app notes to design using cores from other companies. Also, look at http://coefs.uncc.edu/mnoras/files/2013/03/Transfo... (something I stumbled upon while googling to write this reply).

There are lots of strange numbers and equations involved that to the unfamiliar may look like voodo magic. But once you do it a few times you come to realize that Steimetz equations and coefficients are a means of putting the manufacturers charts of material characteristics into an equation, and those numbers to a strange power for thermal are really just figuring temperature rise of a transformer from a straight thermal design standpoint as if the transformer was just a rectangular box.