# Need help interpreting the output of this oscilloscope

#### Creasion

Joined Sep 7, 2019
5
Ok so for a school project i'm working with summing operational amplifiers. Now, look at this circuit:

Ok one thing that stands out is that the frequency differs for both voltage sources, V1 having a frequency of 1kHz and V2 a frequency of 10kHz.

Now when this thing is hooked up to the oscilloscope which measures the value of Vo, what do you think the output would look like?

Formula for the output voltage of summing op amp

VO= -RF(V1/R1 + V2/R2 + V3/R3 +......+ VN/RN)
Where N is a positive integer value.

Now this is what I got as an output:

I just need someone to interpret what exactly i'm looking at here.
Thank you.

#### schmitt trigger

Joined Jul 12, 2010
201
Channel 1 and 2 have different vertical scales!
If the yellow trace is the output, it looks correct. But set the vertical scale to the same V/div.

#### SamR

Joined Mar 19, 2019
2,035
Not sure what you are doing with the cursors, but everything is there under Meas f, phase shift, Vpp.

#### crutschow

Joined Mar 14, 2008
24,723
I just need someone to interpret what exactly i'm looking at here.
Glad to, but you have to tell us that.
You have one output and two traces, so what are the two oscilloscope inputs connected to?

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#### JoeJester

Joined Apr 26, 2005
4,259
you have the yellow trace at 5v/cm and the green trace at 1v/cm

#### Creasion

Joined Sep 7, 2019
5
Glad to, but you have to tell us that.
You have one output and two traces, so what are the two oscilloscope inputs connected to?
The two oscilloscope inputs are connected to r1 and r2.
What do you mean by traces.
Also where are the inputs and outputs on the screen?

#### SamR

Joined Mar 19, 2019
2,035
What do you mean by traces.
Well it used to be the ray-traces on the CRT screen of an analog scope but we still call them traces although now digitally processed and displayed on the high definition pixilated screen of the scope.

#### JoeJester

Joined Apr 26, 2005
4,259
The two oscilloscope inputs are connected to r1 and r2.
The yellow one is trace 1 and the green one is trace 2.

Your INPUTs do NOT state the peak or rms amplitude of their respective signals.

At what point on R1 and R2 are the probes connected?

What do you expect for an output based on your calculations?

#### crutschow

Joined Mar 14, 2008
24,723
What do you mean by traces.
The wiggly lines on the screen.
What do you call them?