Without reading through the entire thread, this looks like the lack of a ground. If you are using differential input to the scope, the source still has to have some kind of a ground reference or the noise will get though.
Tie the safety ground and the neutral together and connect the scope probe ground clip to that point. Then connect the scope probe tip the the hot output. Look at it singled ended. Worst that could happen is that you could blow a fuse/pop a circuit breaker in the generator/inverter/wall outlet.
2V/div with a 1:1 probe. You have a 10:1 probe so it is 20V/div. Next is the red know turned to "cal". I think not.Volts/Div setting at 2
Looks like 16mS for one cycle. 1/60hz=16.67mSTIME/DIV setting at 5ms
You may want to make sure of that.2V/div with a 1:1 probe. You have a 10:1 probe so it is 20V/div. Next is the red know turned to "cal". I think not.
Are you sure that is not a camera shutter effect?it looks like you have an intensified trace.
While I would not rule that out the thread starter has posted several images and if I see things correctly they all look to have an intensified portion of the sweep. With that in mind and how pronounced the intensified portion of the sweep looks I just tended to see it as a result of the A & B sweep speed settings. Purely a guess on my part. Also the A & B sweep time per division do not seem to be indexed the same. Beats me?Are you sure that is not a camera shutter effect?
You can get some odd things when taking pictures of a CRT screen.
Look at this:
The selector switch below the TIME/DIV controls is clearly set to A,Also you want to make sure both your A and B Time/Div knobs are set the same
You can get some odd things when taking pictures of a CRT screen.it looks like you have an intensified trace.
I seem to be having a bad day with attachments, I have repeated the whole post.I also can't seem to get the link you were kind enough to post to work.
I seem to be having a bad day with attachments, I have repeated the whole post.
JimB
Are you sure that is not a camera shutter effect?
You can get some odd things when taking pictures of a CRT screen.
Look at this:
Earlier in this thread The Electrician did some tests to ascertain the usefulness of a "filament transformer" as a means of making isolated measurements of mains supply waveforms, with particular reference to harmonic distortion.
His tests are here:
Testing AC Line Quality with an Oscilloscope - Generator power quality
I have an older analog Hitachi Oscilloscope V-1050F. I want to see the sinusoidal waveform for several power generators I have. I've watched probably a dozen YouTube videos on this but am still not sure. If I use an isolation step transformer, will that change the waveform or just the voltage...www.electro-tech-online.com
His results were good, this lead to the conclusion that a simple mains transformer had a better frequency response than one may expect.
As a follow up to that, I did a few experiments on two transformers that I had in my "junk box".
One transformer was a 240v to 12v 3VA type, the other was a 240v to 9v 12VA type.
Both transformers are of the split bobbin type with the primary and secondary isolated from each other, rather than the secondary being wound over the primary as was usually the case with older transformers.
I used my function generator to inject 7.5v into the primary of each transformer, and used the oscilloscope to measure the voltages at the primary and secondary terminals of the transformer as I varied the frequency of the function generator.
I put the results into a spreadsheet and created a graph of the voltage transformation ratio of the two transformers.
The graph:
View attachment 120292
Note that a higher transformation ratio indicates a lower voltage at the secondary of the transformer.
The 12VA transformer shows a reasonably flat response up to about 2kHz, the voltage then drops off slowly as the frequency is increase to 100kHz.
Above 200kHz the voltage drops off quire rapidly.
The smaller 3VA transformer has a reasonably flat response up to 40 to 50 kHz and then rises, falls and rises again as the frequency is raised to 500kHz, which was the limit of my test.
Further investigation showed that the 3VA transformer exhibited resonances at 120 kHz and 533kHz.
JimB
(Please excuse the thread drift).
We (more or less (+/-)) have more than one thing going. I think for your job, do what is working. Some of us work on power line applications where we could use a poor man's dif-probe where the transformer will work. My applications often have me looking at a signal where neither end is connected to neutral or ground. I have put micro computers on the hot line. You can't connect a scope ground to that type of computer. But the transformer will give isolation and differential.I'm again a bit confused......
Just for the benefit of anyone who finds this thread later.
The method suggested by ReloadRon, RonSimpson and others allowed me to get the sine waveforms I needed.
I used the same setup for all my generators AND the House AC current.
ONE Channel
PROBE set to 10x
GROUND clip from probe connected to Neutral
PROBE TIP connected to Hot
JimAre you sure that is not a camera shutter effect?
You can get some odd things when taking pictures of a CRT screen.
Look at this:
Also for the benefit of anyone reading this thread, that's a seriously BAD idea.
Assuming the scope is earthed, as it should be, such a connection would immediately blow the GFCI/RCD (earth leakage trip) due to the voltage difference between Neutral and Earth.
It 'should' work OK in the scope of this thread, with a non-earthed generator, but not with a normally wired house.
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