Life-Sized OP-AMP!? - How do OP-AMPs work?

The op-amp is one of the most important analog components. It has so many functions its hard to name them all, but in this video I cover the most popular use cases.
-- Links --
Buffer: sinelab.net/img/diy_op_amp/bu...
Differential Amplifier: sinelab.net/img/diy_op_amp/di...
Integrator: sinelab.net/img/diy_op_amp/in...
Inverting Buffer: sinelab.net/img/diy_op_amp/in...
Supply Splitter: sinelab.net/img/diy_op_amp/su...
Op-Amp: sinelab.net/img/diy_op_amp/sc...
My Website: sinelab.net
--

[@newmonengineering]

Just found this channel, I'm surprised you don't have more audience yet. I subscribed immediately, great content. Keep up the great work you will become popular soon I do believe.

[@SineLab]

Thanks for watching!

[@gkdresden]

Op amps have been invented due to military needs. Allready in the 1920ies it was necessary to perform calculations of the trajectory of canon projectiles across long distances. This was done by use of vacuum tube op amps in more or less complex analog computers. Allready at this time there were multiple vacuum tube functions integrated in one system, the first integrated circuits involving additionally passive devices, like resistors and capacitors.

[@marcdraco2189]

Performing mathematical operations - hence "operational" amplifier. The discrete one didn't arrive for many more years the 709 was the first big one I think. I did a version of the Jensen 990 which is a good deal more complicated but functionally identical. Now people probably mock the 2n3904/6 as being old. But get this, at 100 uA of collector current they are the cheapest very low noise transistor out there. Of course, this means the next stage has to do some serious work but with additions like a current mirror and a constant current sink in the tail and that thing's performance is out of this world. I suspect paralleling a few up would make things better, although I've used a MAT02 in my design for the ultimate front end.

[@redmist4963]

All we need now is to compare the diy opamp with an integrated one. Would love to see the performance difference

[@SineLab]

That would be a great comparison!

[@PainterVierax]

should be quite horrendous even with high tolerance resistors and hand selecting the transistor pair. Could be a lot more stable thermally just by using a couple of TO-220 bolt together for the differential circuit but clearly outperformed by any jellybean IC.

[@neoruss3553]

Yeah i a wondering this too. I think the lowest signal that can be amplified would be 0.6 V because that's the threshold for transistor to turn on?

[@azurehydra]

Awesome video.

[@SineLab]

Glad you enjoyed it!

[@albertluna1001]

great video!!!

[@SineLab]

Thank you!

[@libaant.10m91]

Good teach this video is very helpful 👍

[@SineLab]

Glad to hear that!

[@ilyass_bouarasse]

Nice ❤

[@jboy6944]

You explained this so well. I’ll definitely be buying the calculus book😅😂

[@SineLab]

Good idea :)

[@amramjose]

Very nice. Do you sell the pc board for the basic op-amp?

[@kemaruproduction]

Just a reminder, keep the music low for professionalism. Also utilize a fixed camera angle. I am trying to help, dont get me wrong. Explanations are nice and dandy, and thanks for them.

[@kaluvanhariharan4256]

nice video. what is the capacitor C1? connected between base and emitter pof 2n3906

[@SineLab]

That's the compensation capacitor and it stabilizes the op-amp. Without it, the the op-amp oscillates. So, the capacitor is there to dampen those oscillations.

[@smizmar8]

Hi my friend, love your channel! I'm a noob, i used to work in an EE lab, but not as a tech lol. So now I'm trying to educate myself. With your supply splitter, I cant get it to work in falstad. It might be an issue with falstad, but I have a feeling it's an issue with me. So I wanted to ask, what are the outputs? I tried 12v dc for vcc, but for the life of me can't figure out how to arrange vee and ground to get the negative output, and adjusting the pot only gets me 11.94V-60mV. Any one have any suggestions?

[@SineLab]

This circuit assumes that you are starting with a single power source which you measure from 0 to VCC. Connect your ground to VEE. The output of the circuit is now your 'virtual ground'. In order to get a negative voltage, you need to measure from the virtual ground to VEE. Falstad has a voltmeter which you can use for this purpose. Connect the negative end of the voltmeter to the virtual ground and the positive end to VEE. I hope that this helps!

[@smizmar8]

@@SineLab Ok, thanks!!