7 VCA's and 5 papers about convert your poti!! 4046 again.

[Scott Gravenhorst]

Sorry about the previous one.  Something wierd happened with
my fingers and that fired out without the following:

Well, I would have commented something like: Dang, I wish I
knew how to do that!  (re: 4046 vco)  Anyway, so far, I haven't
been able to make a 4046 work with a linear CV.  However, I must
confess that I have not tried the dual transistor thing.  I was
hoping to do it with just one transistor.  Perhaps my understanding
of transistors isn't good enough...  Bjorn says that one can control
the current coming out of pin 12 to control the VCO freq.  So if pin
12 goes to the collector of an NPN transistor with the emitter 
grounded, it would seem to me that one would control the pin 12 
current by controlling the base current of the NPN.  It seems too 
simple to be true, but could this be done by sending the CV to a 
simple opamp buffer, the output of which then supplies the base 
current through an appropriate resistance?  I have absolutely no 
need for expo control, just linear over 4 octaves, so I really was 
hoping to avoid the dual transistor deal (as you mention is possible
somewhere in the text I think?.)  Don't laugh TOO louldly.

       -- Scott  (who is once again proving where an EE is very useful).


music.maker at gte.net wrote:
>"Bjorn Julin" <bnillson at hotmail.com> wrote:
>>Hi!
>>I have put up 7 VCA cirquiuts and a 5 papers about how to convert a odinary 
>>lin log potentiometer into some
>>other curves.
>>
>>It seams that quite a lot people are wisiting my pages but
>>no contributors!! Shame on you lazy people!!
>>
>>241 visitors to the 4046 page and only two bothered to coment!!
>>Booooo!
>>
>>http://home.swipnet.se/~w-133242/index.htm
>>http://home.swipnet.se/~w-133242/pots.htm
>>
>>Yes i now, im lazy to, and should have said long time ago
>>"thank you for you enurmous contribution to the establishing
>>of open source DIY information" (still copyrighted:) on the net!"
>>
>>Now i have said that to all you DIY list readers!
>>Be happy or not, peace love and ear grease!
>>
>>Reg
>>BJ
>>
>>_________________________________________________________________________
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>
>-- Scott Gravenhorst : On The Edge, but the Edge of What?
>-- Linux Rex, Linux Vobiscum  |  RedWebMail by RedStarWare
>-- FatMan: www.teklab.com/~chordman
>-- NonFatMan: members.xoom.com/_XMCM/chordman/index.html
>-- The 21st century does NOT start in the year 2000!!!
>
>

-- Scott Gravenhorst : On The Edge, but the Edge of What?
-- Linux Rex, Linux Vobiscum  |  RedWebMail by RedStarWare
-- FatMan: www.teklab.com/~chordman
-- NonFatMan: members.xoom.com/_XMCM/chordman/index.html
-- The 21st century does NOT start in the year 2000!!!