Oscilloscope Readings

tindel

Joined Sep 16, 2012
873
Please give us some context of what you're measuring, what you expect to measure, and why it deviates from the expected operation... we can't read your mind. Schematics are preferred.

Having said that, some quick thoughts:
1) The frequency of the triangle wave is 0.4Hz
2) The ringing frequency is about 4Hz.
3) These scopes have a lousy sample depth 1kpoints, if I recall correctly, and is being reduced to 512 since you're using channels 1 and 2. Therefore, it could potentially be 50/100/60/120Hz aliasing depending on where in the world you are located.
4) If CH1 is the input and CH2 is the output of a voltage buffer, then you could have instability in your feedback loop. This is a bit more likely since the 4Hz amplitude is greater when CH1 transitions from rising to falling, and vice versa.
 

MrChips

Joined Oct 2, 2009
25,928
I see a relatively clean triangular waveform on Channel 1, yellow trace, -2V to 2V amplitude, 2.5s period.

I see oscillations on Channel 2, light blue trace, same voltage and period, 8Hz oscillation or ringing.

How are the scope probe and grounds connected? Is there a source of 8Hz oscillation nearby that can account for the oscillations seen on Channel 2?

Tek TBS1104 screen image,jpg.JPG
 
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