tl072

[newperson]

Hi,
What is the smallest circuit that could be build to use as a test circuit for a TL072 IC?

[gregwbush]

The simplest circuit i have built with a tl072 (dual op amp) uses just one of the op amps and is the AMZ op amp buffer

http://www.muzique.com/news/opamp-buffer-layout/

That'll tell you if it works... (assuming that's what you mean by test circuit... if not, please elaborate!)

[newperson]

Thanks for the reply.  I think I would need something using both sides of the amp to make sure the ICs fully work.  And yes this is what I am looking for in a 'test circuit.'

[LucifersTrip]

can't you just hook up the same circuit separately for both sides of the opamp?

[gregwbush]

It would be very unlikely that if the chip works, one half of it doesn't, but i understand you want peace of mind 

You could do as LucifersTrip suggests and build a dual buffer

As it happens, i did a vero (strip-board) layout some time ago for one... I'm just labeling components better for you now, and i'll post it....

Ok here it is

[jk-fm]

Triangle oscillator! 3 resistors, 1 cap, + 2 resistors for vref

[gregwbush]

you can plug a guitar into mine 

[pufferton]

It would be very unlikely that if the chip works, one half of it doesn't, but i understand you want peace of mind 

You could do as LucifersTrip suggests and build a dual buffer

As it happens, i did a vero (strip-board) layout some time ago for one... I'm just labeling components better for you now, and i'll post it....

Ok here it is

has this build been tested and verified? im trying to build it and running into grounding issues...(continues popping and LED flashes) but not seeing any issues with it...

[psychedelicfish]

has this build been tested and verified? im trying to build it and running into grounding issues...(continues popping and LED flashes) but not seeing any issues with it...

The layout looks perfectly fine to me. Are you sure you've wired everything correctly and that there are no solder bridges, badly cut traces etc.? Popping might suggest a backwards electrolytic capacitor, I would recommend checking you have all of them correctly oriented

[pufferton]

just triple checked everything...had some issues, fixed them but still the same problem....would it do this if i had a bad component? i removed the board from the chain and i get 9v from the dc jack and LED shines steady. no 1/4" jacks are hooked as of right now.  as soon as i wire everything back up its flashes and i get 1-2v reading.

[pufferton]

has this build been tested and verified? im trying to build it and running into grounding issues...(continues popping and LED flashes) but not seeing any issues with it...

The layout looks perfectly fine to me. Are you sure you've wired everything correctly and that there are no solder bridges, badly cut traces etc.? Popping might suggest a backwards electrolytic capacitor, I would recommend checking you have all of them correctly oriented

http://postimg.org/gallery/alul4cjk/

so it looks extreamly messy cause i have taken it apart 4-5 times.... 

any idea??

[davent]

Tangentsoft's IC tester. Can be built to test single, dual or quad opamps.

http://tangentsoft.net/elec/opamp-tester.html

[stallik]

Hey! A duplicate post... Ic still looks to be upside down

[pufferton]

Hey! A duplicate post... Ic still looks to be upside down

sorry about the duplicate. i was dealing with two different things and the problems converged. i will try switching it tomorrow. thanks so much for your help!!

[stallik]

No worries, I thought I was having a de ja vu moment - I've had them before