[sdiy] NIC-based wave folder/shaper -- OOPS

[Scott Gravenhorst]

THIS is the correct schematic, I re-read Ian's post and he said that the
output comes off the right side of the 47K input resistor.

My previous post put the output terminal at the output of the opamp.




                   +----------------------o Output
                   |
                   |
                   |    20 pF
                   +----|(----------+
                   |                |
                   |    100K        |
                   +--/\/\/\/\/\/---+
                   |                |
                   |                |
                   |       |\       |
                   |       | \      |
         47K       |       |  \     |
   o---/\/\/\/\/---+-------| - \    |
                           |    \   |
 Input                     |     >--+--+
                           |    /      |
          +--------+-------| + /       |
          |        |       |  /        |
          /        |       | /         |
          \        |       |/          |
          /        |                   |
     50K  \        |                   |
          /<--+    +----/\/\/\/\/\/----+
          \   |            100K
          /   |
          \   |
          /   |
          |   |
          +---+
          |
          |
        -----
       / / /




Ian Fritz <ijfritz at earthlink.net> wrote:
>At 11:03 AM 1/26/2003, Scott Gravenhorst wrote:
>
>>Is this correct?  I love simple things like this.
>
>Your schematic is correct.  Thanks for taking the trouble to do 
>it!  Remember that you may need to add 20 pF or so around the upper 100k.
>
>>Should the 100K resistors be 1% ?
>
>No.
>
>>Also, is there anything to be gained by changing the ratio of the 2 100K
>>resistors to something other than 1 to 1?
>
>The analysis is just a bit more conplicated with different values and the 
>response will be different.  If you want to make the triangle accurate 
>there will have to be a trimmer somewhere, but I haven't gotten that far yet.
>
>   Ian
>
>

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