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simple transformer Q

I am calculating AC flux density again. (I do this every few years.)

I recall some formulas use 4.0 in the denominator and others use 4.44. I think it has to do with waveshape but my dementia seems to be taking over.

thanks, Bob N9NEO

Reply to
Yzordderrex
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3 rd hit on google:

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Page 6

Difference is wave shape as you wrote

Cheers

Klaus

Reply to
Klaus Kragelund

SI units:

N = Vrms / (4 Bmax Ae F)

Vrms == Vpeak for a square wave.

For sine, use Vrms and use 4.44 coefficient (actually pi*sqrt(2)).

If you carry a m / u / M through, you get units handy for SMPS work: N (turns) == (V) / ( (uV.s / (mm)^2) (mm^2) (MHz) )

Datasheets sometimes give Ae in cm^2, just mentally shift the decimal over.

Or type it in, with all units, and let Google Calculator figure it out. No one actually needs to know unit conversions anymore. (Downside: Google doesn't understand cgs units (Oersted, Gauss..).)

Tim

--
Seven Transistor Labs, LLC 
Electrical Engineering Consultation and Design 
Website: https://www.seventransistorlabs.com/ 

"Yzordderrex"  wrote in message  
news:cf54cb4a-0ca9-4b98-980d-703d5586b824@googlegroups.com... 
>I am calculating AC flux density again.  (I do this every few years.) 
> 
> I recall some formulas use 4.0 in the denominator and others use 4.44. I  
> think it has to do with waveshape but my dementia seems to be taking over. 
> 
> thanks, 
> Bob 
> N9NEO
Reply to
Tim Williams

Thank you.

Reply to
Yzordderrex

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