A Quick Beginner's Introduction to Op Amps - eBook

Great thanks!  Can you let us know which figures you're referring to...we'll get it fixed!  On figure 4, 6, 7, and 8, it looks like there is a +12V supply at the top and a -12V supply at the bottom.

On the LTspice images, the voltage rails supplied to the Op Amp are both positive. One needs to be positive and the other a negative voltage rail. Good job though.

I was actively already logged in, and it was essentially asking me to make a profile before it would let me, so I didn't.
Oddly enough though, the problem seems to have been fixed, as I just tried again, and it downloaded no problem.

Thanks for the feedback! We understand what you're saying...op amps is a huge topic. With this ebook, the intention was to give an overview to someone who might not be familiar with op amps at all.  We probably should have named it differently...we'll do that, along with the other fixes that should go in. 

Hello,
You should be able to login with your usual account details, and then it'll prompt you to confirm those details when you go to download.

It's a little nuance while we deal with some coding in the back end of the site unfortunately. It should be fixed in a few weeks. Sorry for the inconvenience.

That is called closed loop gain.

It was my understanding that the voltage gain is a ratio of the feedback and input resistors and therefor unitless.

Did the same with me too 

Why is it making me create a profile before allowing the download, when I'm already signed in with one ?

Yeah, this is too brief.  Most opamp chip producers offer free information summarizing opamps:  TI offers "HANDBOOK OF OPERATIONAL AMPLIFIER APPLICATIONS" by Bruce Carter & Thomas R. Brown, SBOA092A, and "OpAmps for Everyone", SLOD006B, by Mancini plus many others.  National (now part of TI) produced "National OpAmp Circuit Collection" AN-31.  Analog Devices makes "Op Amp Applications" by Walter Jung available.  Many good sources of opamp info are available including basic approaches.  Bonnie Baker (formerly TI now with Microchip) has authored many useful appnotes including AN723 from Microchip.  Some of these are big publications but they address basics quite early on.  There are also countless YouTube and other source videos on all the common opamp topics including simulation using LTspice, EasyCAD, etc.