MJLorton Solar Power and Electronic Measurement Equipment Forum
Youtube Video Episodes => YouTube Video Episodes => Topic started by: birrbert on August 01, 2014, 10:29:49 AM
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Hello!
Nice video Martin! Certainly, for me as a beginner oscilloscope user it was useful, but please do the follow-up as soon as you can. I'm feeling very strange (stupid?) after learning about this issue. I mean, it seems like such a simple thing and still one can't properly measure a rectified signal on a bench oscilloscope, be it cheap or expensive; there's no reality to it at all. :-\
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Yes, nice simple video and nice easy to follow explanation.
With the blue Siglent you are seeing the effect of the power supply in the scope making itself felt. If you take the blue scope and power it up, connect the probe then either put only the tip of the probe on a grounded point, or connect the probe ground to the input tip only of another mains referenced scope you will see a mains frequency ripple on the screen of both scopes. This is from the power supply of the blue Siglent which is using a capacitor across the isolation boundary to reduce HF noise from the supply. Only solutions are to ground the secondary side to mains earth ( which defeats the point of having a scope with isolated inputs), power it off internal batteries when in use and only power it to charge, or use a better power supply.
A better supply would have a grounded interwinding shield, and an isolated secondary with no capacitor to ground. It would have to be a grounded unit, and would have to have a minimum of 3kV isolation to mains earth on the secondary side ( to be the same as the scope itself) and the power cord and connector to the scope will have to be rated to that as well, and will have to pass the IEC finger test as well for isolation and touch distance. Otherwise a grounded power supply and a small DC-DC converter in the scope itself to provide the isolation needed.
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Hey Martin ,
How do you like those handheld Scopes and how do they compare to Desktop scopes ????
Thanks
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Hey Martin ,
How do you like those handheld Scopes and how do they compare to Desktop scopes ????
Thanks
Interesting question...I have a little love / hate relationship with handheld scopes. My first scope was a Hantek handheld and I traded it for a bench scope because I wanted better ease of use (turning knobs vs pushing buttons) and improved performance.
If I have the choice I prefer using a bench scope. But there's quite a few benefits to a battery operated handheld as demonstrated (portability, isolation, robustness).
Show me a handheld with knobs, robust and good performance...and I might be won over :)
Cheers,
Martin.
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Hey Martin ,
How do you like those handheld Scopes and how do they compare to Desktop scopes ????
Thanks
Interesting question...I have a little love / hate relationship with handheld scopes. My first scope was a Hantek handheld and I traded it for a bench scope because I wanted better ease of use (turning knobs vs pushing buttons) and improved performance.
If I have the choice I prefer using a bench scope. But there's quite a few benefits to a battery operated handheld as demonstrated (portability, isolation, robustness).
Show me a handheld with knobs, robust and good performance...and I might be won over :)
Cheers,
Martin.
Thanks for answering
I was looking for a handheld or something cause I work off my kitchen table right now which has to be put away each time I am done and with my small kids it's hard to keep stuff out that I was working on .. It really doesn't matter right now cause soon after you responded.... The company I worked for shut down with no warning and fired everyone ..So buying a handheld or digital is out of the questions unless it's super cheap ... Thanks for the info anyways ...
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Heavens! I hope you find employment soon!