Author Topic: Inside the Owon P4603/P4305 linear PSU  (Read 5323 times)

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Offline Pnoxi

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Inside the Owon P4603/P4305 linear PSU
« on: March 14, 2019, 04:08:58 pm »
Today I bought a new power supply Owon P4603 60V/3A, 180W, resolution 1mV/1mA, 3.7 inch TFT LCD display, RS232 - 137.55€ (My version does not have USB and Voltage/Current Curve)



Some components:
4xNPN - NJW0281G
CPU - GD32F103 + C8051F350 (ADC,DAC?)
Op-amp - SGMOP17C ?
Toroid 250VA ?

Pros:
60V/3A (P4603), 30V/5A (P4305)
Linear PSU
Nice, clear display shows all the necessary information
Simple, intuitive control
Response time <100uS (I can't verify it!)
Adjustment accuracy 1mV/1mA
Power measurement
Backlit button (Output On/Off)

Cons:
The Keylock button must be held for at least 10 seconds
Unable to switch off OVP, OCP (maximum set value 3.1A / 61V)
The changed settings are not saved immediately (system settings, stored values), the PSU must be left on for some time
It is noisy at maximum load
It does not have a USB only RS232


Manual:
http://files.owon.com.cn/probook/Single_Output_Power_Supply_USER_MANUAL.pdf

Site:
https://www.owon.com.hk/products_owon_1ch_liner_dc_power_supply

Few photos:















« Last Edit: March 15, 2019, 12:11:20 pm by Pnoxi »
 
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Online Kleinstein

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Re: Inside the Owon P4603/P4305 linear PSU
« Reply #1 on: March 14, 2019, 04:37:01 pm »
The shunt and the power transistors look good. However the current rating on the transformer is somewhat suspicious, as I don't see a switched mode part. Normally a 3 A transformer is good for some 1.8-2 A of DC current (if the filter cap is no too large). So I would be a little careful using the full 3 A current for an extended time, especially at higher voltage.

The ratings on the transformer could be about 220-250 VA: 3 A at some 65 V + some smaller windings.
The 65 V value is rather high - lots of spare voltage for ripple.

THE C8051F350 sound like a µC with integrated high resolution ADC.
 

Offline Pnoxi

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Re: Inside the Owon P4603/P4305 linear PSU
« Reply #2 on: March 14, 2019, 09:05:52 pm »
A weak transformer is a problem for most cheap power supplies. :-[
Behind the cooler are two relays for connecting the transformer winding.

I made a video review, you can find it in the first post. (I don't have an oscilloscope for a more accurate review...)
« Last Edit: March 14, 2019, 09:28:31 pm by Pnoxi »
 
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Offline Pnoxi

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Re: Inside the Owon P4603/P4305 linear PSU
« Reply #3 on: March 26, 2019, 10:17:59 pm »
Here are some images from oscilloscope. I'll do a more thorough test later.

Set voltage is 3.3V.

Power On (Main Power 230V)


Short (CV -> CC):

 
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Online Cliff Matthews

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Re: Inside the Owon P4603/P4305 linear PSU
« Reply #4 on: April 05, 2019, 02:42:41 pm »
Good review. If Owon could drop the price another $50, these would fly off the shelves! I like the vertical layout and deeper cabinet, it makes for more bench room (perhaps they could have tilted the display up 10-15 degrees). One thing about your changes not being saved (eg: at 3:52 you were supposed to hit OK to confirm changes).
 
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Offline Pnoxi

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Re: Inside the Owon P4603/P4305 linear PSU
« Reply #5 on: April 05, 2019, 05:03:45 pm »
Hello,
My changes will not be saved even if I press OK.
It must go some time on to save it. Probably the changes are stored in the EEPROM through the task at regular intervals.

And see the results from the oscilloscope measurement, it doesn't look nice.
https://www.eevblog.com/forum/testgear/inside-the-owon-p4603p4305-linear-psu/msg2298918/#msg2298918
 

Offline tooki

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Re: Inside the Owon P4603/P4305 linear PSU
« Reply #6 on: April 07, 2019, 03:59:17 pm »
Ugh, the fonts! Why use a nice TFT, only to make it simulate crappy 7-segment LCD? Why not use a proper font (and a nicer font for the labels, hotkeys and stuff)… Seems like a slow update rate on the meter, too. (The set voltage seems to update quickly, but the actual measured output seems to lag significantly.)

And that buzzer would make me want to kill myself. It can't be THAT hard to make pleasant-sounding beeps instead of the sound of squeaky toys being tortured.

Pity, it's just software issues on what seems like decent hardware.
 

Offline Phildem

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Re: Inside the Owon P4603/P4305 linear PSU
« Reply #7 on: May 17, 2019, 07:43:43 pm »
Hi,

I just tested one. Not so bad but the OVP and OCP are useless, and NOT SAFE.
If you set OVP to 6V and set output to 25V, there is 25V at the output and after a delay, it switch off.
The delay is long enough to kill any electronics...
I'll mad a video on it tomorrow and show it.
 
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Offline Pnoxi

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Re: Inside the Owon P4603/P4305 linear PSU
« Reply #8 on: May 18, 2019, 08:13:26 am »
Yes, OVP and OCP are slow. I do not understand why they did not solve it software in order to limit the maximum voltage and current setting according to the set OVP and OCP :palm: :-//

What is your software version? I have 1.4.0
« Last Edit: May 18, 2019, 08:15:08 am by Pnoxi »
 

Offline Phildem

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Re: Inside the Owon P4603/P4305 linear PSU
« Reply #9 on: May 18, 2019, 08:40:29 am »
Hi, Yes me too but more of that it's inefficient.

Example : OVP Set to 13V Output set to 22V, if I enable the output, I got 22V for near 400ms ! greatly enough to kill any electronics. (see scope screenshot)

It's not a bad PSU but for me OVP and OCP are useless and should be ignored

My Firmware is 1.4.0 too.
I haven't seen any upgrade available, but the manual on OWON website show enhancement.
« Last Edit: May 18, 2019, 08:42:33 am by Phildem »
 

Offline exe

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Re: Inside the Owon P4603/P4305 linear PSU
« Reply #10 on: May 18, 2019, 12:07:40 pm »
Why use a nice TFT, only to make it simulate crappy 7-segment LCD?

I actually like it this way.

The ratings on the transformer could be about 220-250 VA: 3 A at some 65 V + some smaller windings.

I see "300" on the photo. Of course it's not granted the rating is real. Only load testing and temperature measurement can tell the truth.
 

Offline exe

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Re: Inside the Owon P4603/P4305 linear PSU
« Reply #11 on: May 18, 2019, 12:19:13 pm »
I see the psu allows setting separate CV/CC and OVP/OCP. I don't get why OVP/OCP are needed.
 

Offline Phildem

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Re: Inside the Owon P4603/P4305 linear PSU
« Reply #12 on: May 22, 2019, 07:41:41 pm »
Hi,

My video review about this supply (In French)

https://youtu.be/lUjqdLF8L-8
 

Offline M1ch4L

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Re: Inside the Owon P4603/P4305 linear PSU
« Reply #13 on: January 24, 2020, 09:52:49 pm »
Hello everyone.

I'm thinking about to buy this power supply. Owners ... after a few months of use … are you satisfied with this?
I am new in electronics and I want learn about repairing notebooks, phones, etc ... one important question is: Can I find the short on the circuit with this supply?   … or if the short is there the output is turned off fast and automatically?
 

Offline RedSky

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Re: Inside the Owon P4603/P4305 linear PSU
« Reply #14 on: August 07, 2020, 06:55:37 am »
I note there is now a rebadged Owon P4603 model on the market:

Multicomp MP710087
https://au.element14.com/multicomp-pro/mp710087/dc-power-supply-1ch-60v-3a-180w/dp/3227421

I have bought one, looks almost identical inside and out to the Owon.  Edit: Except this one has USB connectivity as well as RS232, and newer firmware

At $315 it's fairly well priced for us Aussies, even with its noted issues.





« Last Edit: August 07, 2020, 02:17:32 pm by RedSky »
 

Offline vutt

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Re: Inside the Owon P4603/P4305 linear PSU
« Reply #15 on: August 26, 2020, 07:39:32 pm »
27.08.2020 update: Added inside pic. It looks like 30V version is using lower  temp rated (only 85C) caps. Also brand is different.

Well I pulled the trigger on 30V Multicomp PRO version . In my Country in EU it cost 154 EUR +VAT.
I was hoping that some of the shortcomings have been fixed because newer SW version.
[attach=1]
But no. Same spikes when turning AC power on
[attachimg=2]
And O.V.P. is as slow as with OWON version (OVP was set at 13V)
[attachimg=3]

Also any changes in parameters will require up to 25 sec wait time before actual memory save will happen.

However I'm quite happy with it regardless. It is step up from my Gophert NPS-1601. Well except in noise department.
« Last Edit: August 27, 2020, 09:44:07 am by vutt »
 


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