REVIEW - Owon SDS7102 - A look at the SDS series from Owon

[lemon]

Thanks for the quick reply.

I think that the mods to psu board has finished, after the rf-loop's nice work. The new board of Owon (like TomC has saw us) applies all these changes. If you see how they adding all the smd decoupling capacitors, you have the answer how to doing to yours psu board.

The adaptor board wants more investigation for improvement. We have rf-loop's work again (to 3.2 versions), we have the Siri's observations (the nice turning of diode) for version 3.0 and we wants more investigation to the same directions.

[Carrington]

Unfortunately, many of us can not afford to pay more, and this oscilloscope seems to be the solution, but it turns out to be a problem. 


Anyone know if this is a later/previous version of the SDS?

Wow 800€!
http://www.reichelt.de/Oscilloscopes-Spectrum-Analyser/PEAKTECH-1260/3/index.html?;ACTION=3;LA=2;ARTICLE=113054;GROUPID=4044;artnr=PEAKTECH+1260

[lemon]

It is a clone oscilloscope by PeakTech Company.

From what I saw at the links http://www.peaktech.rce.it/index.php?main_page=product_info&cPath=79_81&products_id=350
http://www.peaktech.de/productdetail/kategorie/digital-oszilloskope/produkt/peaktech-1245.857.html
it is a clone of SDS7102V with the same firmware! They have the same series like Owon!

It is very strange that they have the same fw. What hell is going there? Who is made the fw, finally?

[rf-loop]

Made by Owon.

They can do it with your own boot up image and front panel logo.

If you want sell these with KingKong name, just draw your logo etc and pay.

With Aktakom name these have been long time.

[Carrington]

Well, now know two brands more that we should not buy because they are also rubbish. Thanks rf-loop. 

[TomC]

It is very strange that they have the same fw. What hell is going there? Who is made the fw, finally?

I believe it's made by Owon, however, I found a small difference on the firmware on page 105 of the PeakTech manual. The probe menu doesn't have the current option.

[TomC]

I just found a new version of the Oscilloscope software at the Owon site (2.0.8.17). The only difference I found so far is a new "SCPI Command Line" button on the Remote Control Panel. However, when you try to use it emits an error message "SCPI is not support for the machine". SCPI (Standard Commands for Programmable Instruments) is widely used by other test equipment manufacturers.

I also checked the LAN interface to see if they had fixed any of the long standing problems, but no luck. Image transfer doesn't work and High Memory Depth still causes the scope to freeze if the Acquire Length is 10M.

Edit: Just noticed the splash screen and About screen are also different, they show DS-WAVE instead of Owon.

[TomC]

The attachment is a preliminary schematic of my original PSU (PCB-T115-N rev 3) that I've been working on for the last few days. Since I now have a new PSU I'm planning to do some modifications on the original PSU and I thought a schematic may help me better understand what I'm doing. I haven't double checked this so there may be some errors or omissions, please let me know if any are detected.

[lemon]

Very nice and precisely work! Well done TomC, thanks for that (bravo  ).
From what I have seen at the new yours psu board (optical comparison) there are some new reroute paths and a lot of decoupling capacitors.
Unfortunately, I don't expect a significant improvement in software of this oscilloscope.

[lemon]

How many amperes must to be the 10mH smd inductor of line 5.4V?

[TomC]

How many amperes must to be the 10mH smd inductor of line 5.4V?

I don't know that there is an SMD inductor. If you are talking about the battery charging circuit, I know that there is a current sense circuit in the feedback loop (IC2C monitors the voltage drop across R14, R14A, R14B), so the charge current will be limited by this. However, I haven't investigated what the exact value is yet. There is also an overcurrent circuit built into the battery pack's PCM circuit. I'm currently working on a theory of operation paper for the entire PSU, I'll post what I have when I make a little more progress.

[Carrington]

How many amperes must to be the 10mH smd inductor of line 5.4V?

If is this (marked in red), look at the datasheet of the AOZ1094 (Alpha & Omega), but 3A for sure. And SMD mark is: 100 -> 10uH
Wow 5A at least. http://www.coilcraft.com/mss1278.cfm
Another thing: In the 3.0 version the LCD power is a AT1780 (Aimtrom). Vin = 6V (Max)

[TomC]

I know that there is a current sense circuit in the feedback loop (IC2C monitors the voltage drop across R14, R14A, R14B), so the charge current will be limited by this. However, I haven't investigated what the exact value is yet. There is also an overcurrent circuit built into the battery pack's PCM circuit.

The current sense circuit is set to limit the supply's output current to about 3.75A, the PCM circuit kicks in if the charge current reaches about 5A and cuts-off the cell connection. This should never happen if the 8.4V supply is working properly. When the output current is below 3.75A, the voltage sense circuit keeps the supply's output at 8.4V.

While researching this answer I discovered that R13, R13A, R13B, R14, R14A, and R14B are mislabeled, they should be 0.1 ohm instead of 1 ohm. Because of this the notes next to R13A are also incorrect. It's a work in progress, so there are bound to be more errors. I'll post a corrected schematic after I do a little more debugging. In the mean time, any member that is interested, please let me know about any other detected errors, or about anything that doesn't make sense.

[mlhstock]

Is it SDS7102V ?

This is really strange. I have lot of documents about S/N 71021303xxx
(SDS7102V)

Something is very strange if there is V3.0 adapter board inside and it is S/N71021303xxx serial.
Is this unit really left from original Owon factory as it is now.
I can not proof it of course - all is possible.
But in this point now, without more data it feels like someone lie.
Btw, is there scope back, scope carton AND scope also display exactly same serial number?

Yes, it is SDS7102V (with VGA and Ethernet options). The dealer said they didn't do any work on the scope and it was from manufacturer. All three serial numbers are the same.

My dealer and Owon agree that I can return it. They already gave me RMA# so I will send it back soon.

[lemon]

@mlhstock = well done!

@ TomC = I don't meant the psu board but the adapter board (version 3.0). Keep your good work!

@ Carrington = Yes, this is that I meant, the inductor in your red cycle (I have an adapter version 3.0). It writes 100 = 10mH but I measured this with value of 3.2mH and I want to change it.

For 5.0A what you thinking about:
http://www.ebay.co.uk/itm/271241147874?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

or with limit of 4.8A the:
http://www.ebay.co.uk/itm/390565310228?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

[Carrington]

Yes, it is SDS7102V (with VGA and Ethernet options). The dealer said they didn't do any work on the scope and it was from manufacturer. All three serial numbers are the same.

My dealer and Owon agree that I can return it. They already gave me RMA# so I will send it back soon.

You were lucky!
 I was not so lucky.
  OWON = No serious people.
   Moreover, they are as false as his instruments specifications, by omission or noncompliance.

[Carrington]

It writes 100 = 10mH but I measured this with value of 3.2mH and I want to change it.

100 = 10uH

Examples:
http://www.alliedelec.com/search/productdetail.aspx?SKU=70153506
http://www.alliedelec.com/search/productdetail.aspx?SKU=70068704

OR

103 = 10uH

Examples:
http://www.alliedelec.com/images/products/datasheets/bm/DELEVAN_API/70033237.pdf


If its value is 3.2uH then is broken. Burned/Scorched...

But I'm not surprised, mine came with an inductance with half coating. That's nothing to what I've seen. 

[lemon]

You've right!
100 = 10uH

[Carrington]

Lemon make only two changes:
  1º remove C36.
  2º make a bridge, as the red square (don´t short it with feedback to R21).

Note: Do not remove C44.

The noise should go down, because you eliminate resonances.

[lemon]

Thanks Carrington for these suggestions.

I have applied some rf-loop's mods from ver.3.2 already, but I'll apply your suggestion at the end of my holidays (in 10 days).

My noise, after psu and adaptor mods (see at post #1307, page 88) ) is almost 48-64mVp-p (Sample Measurement) or 60-70mVp-p (Peak measurement).

I would to investigate the effectes of inductor in line of 5.4V to noise and how is related with various values.

[lemon]

Look at these red arrows.
All these are decoupling smd capacitors that Owon adds to psu board for decreasing the noise level.

At the yellow one, they cutting the connection of power switch metal cage with the gnd (it was an antenna of radiation).
At the orange one, you see the rerouting of ground plane of board.

I think all these modifications was suggested to Owon from rf-loop member.

TomC, can you measure these smd decoupling capacitors? What value have they?

[TomC]

TomC, can you measure these smd decoupling capacitors? What value have they?

I don't have the scope apart right now, however, I will be taking it apart when I finish modifications on the old power supply and put it in. I'll make a schematic of the new PSU then and measure all these new components and compare it in detail to rf-loop's DIY. From what I've seen so far, Owon followed rf-loop's version 2b DIY for their new PSU design, so these capacitors are probably what rf-loop recommended, mostly 220nF. Hope you are having fun on your holiday!

[BBAAHHOO]

Greetings from Russia!!! I became the owner of this wonderful device sds7102v.....And here are my results...

[BBAAHHOO]

[BBAAHHOO]