[sdiy] a bit frustrated

[harry]

Yeah you're right...

Also... pin 8 of a TL072 is Positive... and pin 4 is Negative. Switching these
without a DAMN good reason is often suicide *    ;^)

*(By damn good reason.. I mean sometimes really savvy designers do some strange
shit with the power supply pins... but swapping these two I have NEVER seen...)

Want a bipolar 9V battery supply... use two batteries in series. the Plus
terminal is plus, the Minus is Minus... and the center connection (tap) is
ground.

H^)  harry

ElmacacoX at aol.com wrote:

> OK, I'm new at this too, but I think I know what's wrong.  Op amps need a
> symetrical powersupply,  you need, say 9v+ on the + of the TL082, and 9V- on
> the negtive input, not ground.  this is why it isn't working I reckon.  now
> you'll need the other guy's with the EE degrees to tell you how to build a
> symetrical psu that runs off 9v batteries.
>
> don't dispair, it is worth the effort and frustration in the end.... I
> think....
>
> eduardo