Owon ODP6033 triple power supply teardown

[modoran]

So this is the teardown of the Owon ODP series power supply ( ODP6033 ).

Rear board contains USB, RS232 and LAN connectivity . It uses Wizznet W5500 chip and Sipex SP202EEN for Rs232 to TTL.




The front panel board contains 2 of them sandwitch together:


Binding posts are soldered directly to the PCB itself.

Current shunts are a bit to close to exposed traces, don't like that.


Main processor inside the unit is a Samsung S3C2416XH-40, RAM is a DDR2 SkHynix H5PS5162GFR-S6C part, and NAND is a Micron 1Gb 29f1g08abaea part.

LCD module is an GA4024-IVO which I couldn't find any info on the internet. If it malfunctions this could be unobtanium.

Keyboard is standard rubber keys, encoder does not have any series on it to be easy identified.

[modoran]

Continued as this forum does not allow many pictures ...




Main power transistors is ISC branded NJW0281, total 9 of them, 7 on one side of heatsink and 2 on other side. There is 3 pcs TIP42C and 3 main bridge rectifiers on the same heatsink, along with a transistor as temperature sensor ( don't read the part number, could be something else, not a transistor ) in a TO92 package.

There are 2 toroidal transformers with 3 voltage taps.  I measured 85V DC at the unregulated output which seems a bit too high at the supply delivers only 60V.


There are many OP17 opamps in there and 3 pcs Silicon Labs C8051F350 microcontrollers ( one for each channel ).

Output capacitance on 2 main channels is 100 uF.

[Swake]

Hi Modoran,

Thanks for the pics. While looking for an additional power supply (can never have enough) I stumbled upon your post here and it reminds me of Jerry Walker's video on the same power supply family.


Why would 85V DC be on the high side? I've seen other supplies that have up to twice the output voltage before regulation. Got to build a buffer somehow.

[John B]

85V would be the unloaded voltage? They can use less capacitance that way, the RMS voltage being dropped across the regulator would be far lower under load.

[modoran]

Yes, 85V unloaded voltage, it uses 4700uF caps.   

Don't know how much it drops under load.

[Pfriemler]

#1: Am I right if I see two 100 µF/100V capacitors at the outputs? something I do not like at all esp. with linear PSU, better <10 µF.

#2: complete other topic: what is the possible range of "interval" in the recording function? Default 1 s and 10k points will end up in <3 hrs recording, with 20 seconds about two days. Would be useful for me. Manual and all reviews I saw did not mention it.

[MattM]

Hi Modoran,
have you been using the power supply as well? I have encountered a bit weird behavior relating to the PS fan and wanted
to ask if you've possibly noticed the same or maybe I have a buggy unit.

The fan keeps running in short 'bursts', it comes on, speeds up for about 5 seconds and then goes completely off. This
keeps repeating every few minutes. I draw pretty laughable power from the supply when this happens < 1W (12 V, 0.06A).
I it is incredibly annoying .

Has this happened to you?

Thanks

[modoran]

Yes, I use the power supply quite often. I don't think the fan ever kicks in at no load or the load that small. I never noticed that behaviour, but i have other tools in the lab that makes noise, so it is possible to not notice it.

Edit: Just tested today for 2 hours, ch1 3A shorted output ( about 0,4W on power supply display ), absolutely no fan kicked in.

So your unit is most likely with problems.

[MattM]

Thank you very much for the info and doing the test!

I will contact my supplier, luckily it's still under warrany.

[maralb]

Different Firmware versions maybe??

[MattM]

Possibly, mine is v3.2.0. I wrote to my supplier and OWON regarding this issue. I will let you know the outcome if you are interested and it is okay with modoran. I don't want to hijack his topic.

[modoran]

I am running v3.0.0, Owon is not providing software update very easy ( not on their website ).    Please let's us know how you solved the issue.

[Pfriemler]

"Doctor, nobody really listens to me!" - "Next, please." ...

May one of the known users here answer my questions, please? esp. #2 is important: the setable range of interval for (longtime) data recording.

[modoran]

999999 seconds and 10000 points maximum on my unit.

[Pfriemler]

Wow! Damn, my favourite UNI-T only offers 99999 seconds and 10k points - which is enough for 31 years of continuous recording, if I do the maths ...
No, honestly, I was afraid of something like 15 or 20 seconds.
Who needs an 11-day interval? 

[MattM]

Hi guys,

just to let you know. OWON didn't reply, I tried several times, emails and contact forms. They just don't care, I think.

I tested the power supply with higher loads, the fan ran normally, i.e. just running continuously not in bursts. I suspect it is just weirdly implemented fan control in newer FW.