circiut help reqest

[steven2]

here is a circiut i once collected off the net , its suposed to be some kind of sensitive gravity wave detector , but the details of this ciriut aint to good can some one write the pin numbers down on the circiut here so that i will know what pins are used, on the net there are few tl082 ics listed but some have different details about them , so i dont really know which ones being used in this circiut , i have 2 of these ics but they have the texas instraments logo on them and the details on these are 15c5r5m and under it is tl082cp  is this the correct ic to use , allso before i make this circiut is there any improvements i can make to it to make it even more sensitive, or shall i just stick to the way it is, and allsao i dont have a 2.5uf electrolytic so can i use a 2.2uf and as for the mylar or metal cap i dont have them but can i use something else or what can i use in its place and is the value really that criticle or not

 

[hotwaterwizard2]

TL082 Datasheet and Pinout

 

[audioguru2]

The circuit will work fine with just about any opamps. TL082 dual opamps are made exactly the same by many companies, look at the datasheet to see which pin is which. Most other dual opamps have the same pins numbers.

The circuit is designed to be powered by two 9V batteries, one for +9V and the other for -9V with them joined together at ground.

The 2.5uF electrolytic input capacitor is supposed to pickup the gravity wave somehow. If you use a different one then it might be better or it might not work.

The 2000pF capacitor cuts hiss. Its value can be anything from 1000pF to 4700pF. If a ceramic disc cap is used then it might pickup noises like a microphone because the gain in the circuit is very high.

 

[steven2]

thankyou audio  guru and hotwater wizzard  is the mylar or metal capacitor i think was mentioned in the circiut important i dont have them can i use a substitiute

 

[audioguru2]

I said that a ceramic disc capacitor might be microphonic in the circuit with such a high gain. A mylar or metalized poly capacitor (don't you have a "green cap" of 102 to 472 value?) is what should be used.

 

[steven2]

i need to redraw the design to a more simplified format so it will be easy to biuld by but despite the data sheet posted here i need to know on the circiut diaghram which pins are the pins as listed on the data of the real rectangle shaped ics which unnumberd pin on the actuall  circiut diagram is which are the pin details the same as one of the tryangles in the data sheet here , remeber the tryangle symbol suposeing to represent the actual rectangle shaped chip , i get confused at times myself

 

[steven2]

thankyou audio guru i have greencaps ill check to see if i have the values you mentioned so they can replace the mylar which i dont know much about mylars

 

[steven2]

heres a better redraw to biuld it by is this corect have i got the right pins used as in the unumberd pin circuit

 

[audioguru2]

No Steven,
Look at the pins on the TL082 that Hotwaterwizard attached. It shows a dual opamp. A dual opamp has two opamps in it.

Pin 7 is the output of the second opamp. You have it connected to the positive battery by mistake.

Pin 1 is the output of the first opamp. You don't have it connected to the first volume control, you have it connected to pin 2 by mistake.

 

[hotwaterwizard2]

Here is what I came up with.

 

[audioguru2]

Nice try, John.
Your batteries are backwards.

 

[steven2]

thankyou audio guru and john thats what i wanted to know on the first schematic that uses tryangles i wanted to know the pin numbers for it to compare with the data sheet  so to make it easyer to biuld , well it helps to know  that now i can get it right , we wouldent of had to go through all the trouble if the designer of the first circiut that i posted, which i got from the net,  put the pin numbers in  the first place  thanks guys anyhow . audio guru ill put the batterys around the right way .

 

[steven2]

i just biult it on a bread board top test and it dident work i used an amp at the output and it made a hissing niose so low you can barely here it and it burnt out my 25k pot

 

[audioguru2]

Hi Steven,
I don't see how the 25k pot can burn out.
If something in the circuit is wrong and causes the output to be 9VDC instead of 0VDC then the pot will dissipate only (9 x 9)/25k= 3mW. Its max allowed is probably 500mW.

 

[hotwaterwizard2]

OOPS

 

[steven2]

i rechecked it all and the hissing niose i get you can barely hear it ill replace the batteries when i get more ill get back to you then, thankyou audio guru, and hotwater wizard

 

[hotwaterwizard2]

Here is how the batteries are hooked up just incase you don't know.