everyone loves these things but i cant get my head around it... any explanations seem to go from blindingly simple to technical very quickly... i understand logic comparators but as soon as negative feedback is included i get all confuzzled.(adsbygoogle = window.adsbygoogle || []).push({});

OK so i understand that the output will become G((V+)-(V-)). So if you use 100% negative feedback, i don't undertand why you will get the same output out as you put in... this is what i am refering to - http://web.telia.com/~u85920178/begin/opamp00.htm [Broken] in the first part of the section "The Op-Amp As A Comparator - Analogue"

it says: "The only stable condition that can exist is if the + and - inputs are the same voltage."

however i was under the impression that if the + and - input are the same, the output is 0v because G*(x-x)=G*0=0. therefore this wouldn't be a stable input...

im also quite confused about limiting gain by using resistors and things but i guess ill understand that if i understand the basics...

i hope somebody can help...

thanks!

sam

**Physics Forums | Science Articles, Homework Help, Discussion**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Op-amps arrrgh

Loading...

**Physics Forums | Science Articles, Homework Help, Discussion**