Hello there.

I have been working on this for a couple of days taken from juggling pirate. I can't get an increase or decrease in voltage when adjusting the pot. I noticed the polarity was incorrect to the TL081 in the original diagram. so have adjusted it on the cad drawing. Any help would be appreciated.




I copied the schematic to a cad program.

http://postimg.org/image/62moj5och

Have you connected pin 7 to 12V and pin 4 to ground? The original circuit does not show this but it's required to power the op-amp.

Thanks for the reply. I have only connected what is on the schematic. So I need to add 12v to pin 7 and pin 4 goes to ground? I added the TL081 diagram to show what connections I am using.

updated schematic below.

http://postimg.org/image/cv1cu2c15/

Yes. Try that and see how you get on.