- #36
Femme_physics
Gold Member
- 2,550
- 1
I'll just fix the mA later... :) forgot http://img17.imageshack.us/img17/4534/800rgy.jpg
Last edited by a moderator:
Femme_physics said:I'll just fix the mA later... :) forgot
I like Serena said:Now it truly looks like micro (μ or u)!
Do you want to make me cry?
And apparently you forgot the second time.
Oh, and I just noticed.
At the top you write "RL = ?".
But you already know RL. I think you meant "ILS = ?".
Femme_physics said:Ah, ok ok! Got it now
Femme_physics said:Good
Thanks a bunch!
So now I could move on to my next exercise...think I'll keep it with this thread. Does it all look right? I got to find Vout when the switch is in state 1 and when it's in state 2
http://img36.imageshack.us/img36/1464/blackblacke.jpg
Btw, how is it that you still have access to the scanner?
Not quite.
First, I get a different value for V+ (only by a little).
And I believe it's not in mV, but in V.
(Nice "m" by the way! )
There is one catch.
If Vout becomes to high or too low, the op-amp is "saturated".
So Vout can never become higher that the positive voltage supply.
And Vout can never become lower than the negative voltage supply.
In practice this means that if V+ is higher than V-, then Vout is the positive power supply.
And if V+ is lower than V-, then Vout is the negative power supply.
Femme_physics said:Still? I'm at home. Dad's napping. I ain't bothering him. :)
Femme_physics said:hehe. had to do a last minute fix-up!
Well, you're right, I got a different result too. V = 5.5263V
I guess I must've mistyped something in the calculator the first time. I should've known that result doesn't make sense.
Is that the only mistake?
Femme_physics said:Oh yea, I remember that!
Got it!
Okay, I just remember that at other times you could not get to the scanner any more...
That's the only calculation error.
But your answers are wrong due to my other remark.
Femme_physics said:Hmm...yea you're right. Oh! That's because we moved the scanner and stationary PC to the livingroom, so I'm not bothering anyone here much. Heh, yea, I forgot! I couldn't use the scanner back then... damn, good old days
Femme_physics said:But my Vout results don't exceed the 7.8V I see signified on the op-amp.
Here's the corresponding wiki page that I recommend:
http://en.wikipedia.org/wiki/Operati...r_applications
It has really nice pictures, a nice overview, and pretty formulas.
I recommend adding the Comparator (the first one, which you would use for the problem at hand).
You probably won't need the others.
You mean this?[itex]V_{out} = (V_+ - V_-) \times 1000000[/itex]And the formula I gave, is the one formula that exactly describes the behavior of an op-amp (up to saturation).
All the other formulas can be derived from that one.
Femme_physics said:You mean this?
[itex]V_{out} = (V_+ - V_-) \times 1000000[/itex]
Femme_physics said:Oh, sorry, I missed the question No, just got into a solving shvoong! Can't stop! Should I?
Femme_physics said:I do actually, and starting to feel kinda tired. Will continue this tomorrow, hopefully. Thank you Klaas!
And I love it!
G'night for now :)
Femme_physics said:So, I think I finally got it :)
Femme_physics said:EDIT: In the wiki article you linked me, there's no reference for the formula of the voltage gain of a non-inverter op-amp. Should we add it?
Yep. That's it... only one problem... the power supply of the op-amp can not yield so many volts. ;)
No reference? Isn't it already there in the 3rd circuit application (Non-inverting amplifier)?
Yeah, otherwise we should add it!
Femme_physics said:Yea, I didn't thought that made much sense...otherwise one amplifier and I could run this entire world!
So, what did I do wrong?
Femme_physics said:so I just write that Vout = Saturated?
Ah so 7.8 [V] :) !I like Serena said:Not quite.
What is the positive power supply of the op-amp?
Almost!Femme_physics said:Ah so 7.8 [V] :) !
7.8 [V] for the positive
-7.8 [V] for the negativeThose are my Vouts
The name of this circuit/op-amp is "comparator" right?
Femme_physics said:I updated and edited the post above u :)
Femme_physics said:it's not -7.8? but we hit saturation point. isn't that the max lowest voltage?