Author Topic: Owon sds7102 and octopus no clean result  (Read 2136 times)

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Offline J4e8a16nTopic starter

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    • Jean Pierre Daviau
Owon sds7102 and octopus no clean result
« on: August 06, 2015, 06:21:51 pm »
Hi,

I tried to use octopus with my Owon and did not get nice results.

http://howtoresolved.com/tube/WWY-pakm_OM/197-simple-v-i-curve-tracer-using-an-oscilloscope-and-function-generator




Could using   sine, square, or saw wave make a difference?

JPD
Equipment Fluke, PSup..5-30V 3.4A, Owon SDS7102, Victor SGenerator,
Isn't this suppose to be a technical and exact science?
 

Offline unitedatoms

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Re: Owon sds7102 and octopus no clean result
« Reply #1 on: August 06, 2015, 06:49:56 pm »
The guy in your first video link mentions that more correct approach is to use current probe or differential probe, because V channel needs to show V only of DUT without added R*I value of current sense resistor. Without the subtraction of R*I value, the V channel will bring unclear values, not exactly what one may expect from I-V tracer.
Interested in all design related projects no matter how simple, or complicated, slow going or fast, failures or successes
 

Offline smpowell

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Re: Owon sds7102 and octopus no clean result
« Reply #2 on: August 06, 2015, 11:37:03 pm »
>Could using   sine, square, or saw wave make a difference?

Use a sine wave. A square wave will not work and a saw wave will distort the results if the DUT has capacitance or inductance,

Also check to make sure the ground on your test circuit is connected to the scope's ground.

However,  I suggest that you try the original version of the octopus circuit instead of the one you found. Look at the classic circuit at the top of my old web page: http://web.archive.org/web/20070909022650/http://octopus.freeyellow.com/octopus.html  Replace T1, R1, and R2 with your sine wave generator.

Back in the old days, transformers were common and the only cheap source of sine waves. Now you could use a sine wave generator, MP3 player, or tone generator program on a computer to get whatever frequency sine waves you want to play with.

As far as explaining the results, I like an old 1975 magazine article. It starts at page 70 here:
http://www.americanradiohistory.com/Archive-Poptronics/70s/1975/Poptronics-1975-08.pdf

Also see: http://www.qsl.net/kd7rem/pdf/octopus.pdf
 

Offline J4e8a16nTopic starter

  • Regular Contributor
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  • Posts: 222
  • Country: ca
    • Jean Pierre Daviau
Equipment Fluke, PSup..5-30V 3.4A, Owon SDS7102, Victor SGenerator,
Isn't this suppose to be a technical and exact science?
 


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