[sdiy] Opto-transistor question

[BrightBoy]

This might help a litte:

http://www.edn.com/article/520604-Use_a_photoelectric_FET_optocoupler_as_a_linear_voltage_controlled_potentiometer.php

Cheers,

Jeff

-----Original Message-----

>From: Harry Bissell <harrybissell at wowway.com>
>Sent: Mar 14, 2012 3:57 PM
>To: Harlan Foster <harlan.foster at gmail.com>
>Cc: Synth-diy at dropmix.xs4all.nl
>Subject: Re: [sdiy] Opto-transistor question
>
>we say "barking up the wrong tree"
>
>Either the transistor or darlington type optocouplers are mostly specialized for switching applications.
>
>There is a FET optocoupler H11 something (someone else will tell you the number) that has been used
>with some success, although like most FET VCAs it has a kind of limited signal input range.
>
>You also want to look at Avago technologies, who make a large number of optocouplers that could easily be suitable for a VCA, although they
>are probably not either cheap or easily available.
>
>I'd also check the list archives, look for optocoupler and that should get you there...
>
>Good luck !
>
>H^) harry
>
>
>
>----- Original Message -----
>From: Harlan Foster <harlan.foster at gmail.com>
>To: Synth-diy at dropmix.xs4all.nl
>Sent: Wed, 14 Mar 2012 15:50:06 -0400 (EDT)
>Subject: [sdiy] Opto-transistor question
>
>Hello all, I've been diving into the SDIY thing for a few years now,
>but I'm still kind of wet-behind-the-ears. Recently I picked up some
>opto-transistors (4N32 & 4N36), I was thinking that they may come in
>handy. I've been breadboarding with them trying to cook up a simple
>VCA, but I've not had any success.
>
>I'm shooting for something simple, I don't mind if the results are
>less than ideal. Am I barking up the wrong cheese? Can anybody point
>me  in the right direction? I have several transistor based VCA
>schematics that I have built in the past, but this has me stumped.
>
>Thanks for the knowledge you all share in this forum, I really enjoy
>this mailing list!
>>Harlan
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>-- 
>Harry Bissell & Nora Abdullah 4eva
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