Help reduce noise on USB oscilloscope.

[Lightium]

Would one of these reduce noise picked up on my USB oscilloscope. https://www.amazon.com/CableMax-Iso...hvlocphy=&hvtargid=pla-4583795275521723&psc=1

 

[danadak]

The noise is not present when you run scope on battery ?

Got a scope pic of noise, and FFT pic of the noise spectrum ?


Regards, Dana.

 

[crutschow]

Under what conditions do you see this noise?

 

[Lightium]

Under what conditions do you see this noise?

Without the probes plugged in there's no problem, but with the probes there's noise(pic one) and shorted with a 15nF cap (pic two) there is still noise. It's a Hantek 6022BE USB scope.

 

[Lightium]

The noise is not present when you run scope on battery ?

Got a scope pic of noise, and FFT pic of the noise spectrum ?


Regards, Dana.

I unplugged my laptop from the charger and noise is gone. Thanks Danadak.

 

[Lightium]

So now instead of USB isolation I need to filter out that 60KHz sine wave between the charger and the laptop. It's too bad these laptop chargers don't come apart easy, I'd take a look and improve.

 

[danadak]

Filtering the 5V USB power supply line

I'm currently working on a new project that contains sensitive analogue components and have rediscovered what many before me already know, that is that the VUSB 5V line that comes out from your com...

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USB 5v power filtering

I am creating a pcb that splits a single USB input into 3 outputs (one with data/power carried, two with just power), and I was wondering what is the best way to reduce noise on the power line as t...

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All leads and grounds as short as possible.

Use polymer for bulk cap, and ceramic disk :

Regards, Dana.

 

[crutschow]

Without the probes plugged in there's no problem, but with the probes there's noise(pic one) and shorted with a 15nF cap (pic two) there is still noise. It's a Hantek 6022BE USB scope

Unterminated probes tend to pick up noise from the either.
Do you see the noise when measuring circuit voltages?

Filtering may not help, since you are seeing radiated noise.

 

[Lightium]

Unterminated probes tend to pick up noise from the either.
Do you see the noise when measuring circuit voltages?

Filtering may not help, since you are seeing radiated noise.

Problem was solved when I unplugged the laptop from the charger.
I did have an idea to put a 420uF cap between charger and laptop.
from this site: https://makingcircuits.com/blog/calculate-filter-capacitor-smoothing-ripple/

I get:
C = I / (2 x f x Vpp)
where I = load current
f = input frequency of AC

 

[Lightium]

I think your right though crutscow, the probes act like little antennas.