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EI-30 obsolete? Help selecting transformer

PostPosted: August 12th, 2019, 9:28 am
by slowpogo
I want to build the σ25 for 24VDC output (115V mains).

I'm having a hard time finding a transformer for the σ24 board. None of the suggested EI-30 transformers, or even their series seem to be available anymore. In fact I'm having a hard time even finding the EI-30 form factor listed anywhere.

Can you suggest a transformer for my purposes (preferably from Mouser) or has this project sadly become obsolete? Thanks

Re: EI-30 obsolete? Help selecting transformer

PostPosted: August 12th, 2019, 10:10 am
by amb
These days EI-30 transformers are plentiful in Europe, but seems to become rare in the US. I don’t know why this is. If you’re unable to obtain an appropriate EI-30, I recommend using a chassis-mount transformer instead.

Re: EI-30 obsolete? Help selecting transformer

PostPosted: August 12th, 2019, 10:50 am
by slowpogo
Thank you. I can't find any EI30 that are both 115V primary and 24V secondary. Would this toroidal work, wired in parallel for 24V:

https://www.mouser.com/ProductDetail/Tr ... 252B6y4%3D

Re: EI-30 obsolete? Help selecting transformer

PostPosted: August 12th, 2019, 12:51 pm
by amb
Yes, that should work fine.

Re: EI-30 obsolete? Help selecting transformer

PostPosted: August 12th, 2019, 7:34 pm
by bk_856er
Allied has a decent supply of EI-30 transformers. I just received a few. But yes, these days for some reason the sources are limited in the USA - the upside is that they are very inexpensive!

BK

Re: EI-30 obsolete? Help selecting transformer

PostPosted: August 15th, 2019, 8:37 am
by brian92fs
I ordered mine a few years ago directly from Zettler (www.zettlermagnetics.com). I had to order 5 to 10, but it was still cheaper that a single toroidal.