Core Material

[roydm]

Hi, I need a little help with designing a transformer for 12 khz.
What should the core material be. Stalloy, Ferrite or something else?
Note: Efficiency is not a requirement.
Thanks in advance.
Roy

 

[ScottyUK]

One of the power ferrites such as 3C85 is possibly an option at a relatively 'low' frequency, as is amorphous iron. What power rating is it - 1mW will get a different solution compared to 1MW. Also, what is the signal - sinusoid, square, something else? Do you need to have low magnetising current to minimise the distortion introduced?

There's not really enough information to work with.


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If we learn from our mistakes I'm getting a great education!

 

[roydm]

Scotty,
Thanks for the response, not high power.
The transformer will be powered from a 4-20 mA transmitter
~ 0.5 V A 12 khz

Regards
Roy

 

[roydm]

Scotty,
My previous should read ~ 0.5V at 12 khz
Roy

 

[ScottyUK]

Probably a pot core from Ferroxcube in something like a 3C85 or 3C90 grade would be reasonable starting point. It's really a ferrite for power applications but the frequency is low, the saturation flux density is high for a ferrite, and you should be able to keep the magnetising current down. There are some helpful design notes in the Ferroxcube Handbook starting on page 17, and I've previously referred to 'Soft Ferrites' by Edgar Snelling as probably the finest work on the subject ever written. You might get a copy through a technical library; it is rare and expensive when it turns up on the second hand market.


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If we learn from our mistakes I'm getting a great education!

 

[zappedagain]

I'll give a plug for Amidon:

https://www.amidoncorp.com/pages/specifications

I've always had good luck with their cores in the MHz range.

John D