Waveform related question

crutschow

Joined Mar 14, 2008
33,971
I am doing electronic project and the oscilloscope capture this waveform. Is this waveform normal?
The answer is an unequivocal, maybe.
My crystal ball is out for repair.
How do you think it is possible to answer that question without knowing what the electronic project is and where in the circuit you are looking? :confused:
 

Thread Starter

caroline_01

Joined Aug 17, 2022
7
It would be helpful if you described where the signal is coming from.
I made connection using Satcom device (need 12v) with 12v dc power supply. I want to check when the power turn off, then how much time it takes to comes down the voltage. I did the power off, then this event captured. I found the dc wave comes down immediately in millisecond. But I don't know why I see some noise or it is something else. Maybe it is normal that is my question.
 

Thread Starter

caroline_01

Joined Aug 17, 2022
7
The answer is an unequivocal, maybe.
My crystal ball is out for repair.
How do you think it is possible to answer that question without knowing what the electronic project is and where in the circuit you are looking? :confused:
Electronic project is connecting power supplies with Satcom devices. I connect positive probe at the input of the satcom (somewhere between the wire connection of power supply and satcom ) and negative to the ground. Sorry maybe it is hard to explain where I made connection. I am wondering to know the waveform what the event I captured is it the right way?
 

dl324

Joined Mar 30, 2015
16,652
I did the power off, then this event captured. I found the dc wave comes down immediately in millisecond. But I don't know why I see some noise or it is something else. Maybe it is normal that is my question.
Power off behavior is generally uncontrolled. Why are you concerned with how the circuit behaves after power is removed?
 

Irving

Joined Jan 30, 2016
3,791
A count says 3 periods over 50 mSec, so that looks like a 60 Hz signal?
I agree, its just 60Hz 'hum', probably induced due to a ground loop - scope ground not directly bonded to circuit under test ground, or induced into -ve PSU output when AC supply turned off.
 
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