Connect with us

FET relay configuration

Discussion in 'Electronic Design' started by tempus fugit, May 28, 2007.

Scroll to continue with content
  1. tempus fugit

    tempus fugit Guest

    Hey all;

    This is kind of picked up from the 'can I do this with a uProcessor' thread.
    Eeyore got talking about using JFETs as a replacement for relays. This is
    what I've come up with, but I'd be glad to know of a better way, since I
    have 4 effects to switch in and out of the signal path, thus putting a fair
    amount of noise and resistance in the path:










    bypass comp bypass flanger
    in
    o-----------------o----------------o ---------oo-------------o
    | | | | |
    |-+ |-+ | |-+ |-+
    | | | | |
    o ->|-+ o->|-+ | o->|-+ o->|-+
    | | | | | | | | |
    etc
    | | | o | | o | o
    | | | | | | | | |
    | |-----------|----o---| | o--------|----o
    | | | |
    | | | |
    | | | |
    | | | |
    | | | |
    |
    ___________ ___________
    control v control v control v control v



    What do you think? There would be 2 more sets of 2 FETs for the remaining
    effects.

    Thanks



















    (created by AACircuit v1.28.6 beta 04/19/05 www.tech-chat.de)
     
  2. D from BC

    D from BC Guest

    Ohhhhh the horror! :p

    Is that some sort of analog multiplexer?
    I think the only good application I've had for JFETS is for DC current
    sources..

    Maybe go mixer style with VCA's...


    D from BC
     
  3. whit3rd

    whit3rd Guest

    Probably the intention is to make a clickless switch (by filtering the
    control voltage signals). Yep, VCAs or transconductance
    amplifiers, like LM13700 and the late SSM2017, are the slick way
    to do this.

    Or CA3080; I see that's now obsolete. Pity, there were some nice
    uses for 'em. The newer designs (LT1228) seem like overperformers,
    far pricier and faster than I like.
     
  4. Marra

    Marra Guest

    Why not use the bog standard 4016 or 4066 bi-lateral switches?
    Cheap as chips !

    www.ckp-railways.talktalk.net/pcbcad21.htm
     
  5. D from BC

    D from BC Guest

    Long ago I heard of THAT Corp. VCA's..
    D from BC
     
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

-