Connect with us

Common mode choke with true bifilar winding?

Discussion in 'Electronic Design' started by Joerg, Jun 30, 2011.

Scroll to continue with content
  1. Joerg

    Joerg Guest


    Designing the umpteenth higher power RF filter here and wondering. Are
    there any truly bifilar-wound common mode chokes? Maybe some niche shop
    in the boonies makes them? I've been through the usual places such as
    Pulse and Gowanda.

    I'd need 100uH or more, 1A of (differential) current with 2-3A
    preferred, thru-hole would be nice but not required, and leakage
    inductance is very critical because of a somewhat sensitive filter
    requirement. 300nH or maybe 400nh could be digested but not more.

    So far I've always done that with some big double-hole ferrite cores and
    coax but this gets old. Mostly because that's bulky, you need 3-4 in a
    row because you can't get more that two turns of RG174 through those and
    the manufacturers never offer any kind of fastening material. Seems the
    issue of having to mount them onto a board or chassis is beneath them.
    Plus it's a custom part we have to hand-wind in production and
    off-the-shelf would be more desirable.

    Commercial ones either have double-chambered bobbins which results in
    horrible leakage inductance or they look like this and still have almost
    2% of nominal as leakage: Photos/51504C.JPG

    Insulation strength between the two wires won't matter, there's never
    going to be more than 100V and there is going to be a safety shut-off in
    case it goes kaputt.
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day