Author Topic: Inside the Owon P4603/P4305 linear PSU (Read 19324 times)

Pnoxi · « **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:

Kleinstein · « **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.

Pnoxi · « **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...)

Pnoxi · « **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):

Cliff Matthews · « **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).

Pnoxi · « **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

tooki · « **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.

Phildem · « **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.

Pnoxi · « **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

What is your software version? I have 1.4.0

Phildem · « **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.

exe · « **Reply #10 on:** May 18, 2019, 12:07:40 pm »

Quote from: tooki on April 07, 2019, 03:59:17 pm

Why use a nice TFT, only to make it simulate crappy 7-segment LCD?

I actually like it this way.

Quote from: Kleinstein on March 14, 2019, 04:37:01 pm

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.

exe · « **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.

Phildem · « **Reply #12 on:** May 22, 2019, 07:41:41 pm »

Hi,

My video review about this supply (In French)

https://youtu.be/lUjqdLF8L-8

M1ch4L · « **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?

RedSky · « **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.

vutt · « **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.

But no. Same spikes when turning AC power on

And O.V.P. is as slow as with OWON version (OVP was set at 13V)

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.

John B · « **Reply #16 on:** June 23, 2021, 10:01:02 pm »

I'm looking at purchasing the Multicomp Pro rebranded version of this unit, the 60V 3A model with USB/RS232 specifically. Am I right in thinking that the issues are still present in the unit?

The other slightly cheaper option is the Tenma branded lineup which I think is a Korad unit:

https://au.element14.com/tenma/72-2550/power-supply-1ch-60v-3a-prog/dp/244541402

My only experience with them is that Dave Jones blew up one like 8 years ago, so I have no info on whether the design has been improved enough over the years. I'm just looking to add another channel with 60V output natively, I don't absolutely need the extra features on the Multicomp unit (power reading is nice), but I'm willing to spend a bit extra if the unit has less issues than the Korad/Tenma units.

MarkF · « **Reply #17 on:** June 23, 2021, 11:47:16 pm »

At that price, I would sooner have the Siglent SPD1305X for $20 more instead of the Owon.
30 volts, 5 amps, USB interface and sense lines.

Defpom did a review:

rdl · « **Reply #18 on:** June 23, 2021, 11:53:50 pm »

They did make changes to fix the Korad power supply. There was a video posted on Dave's "Altzone" youtube channel.

https://youtu.be/uecvB4U1fps

tautech · « **Reply #19 on:** June 24, 2021, 02:03:28 am »

Quote from: MarkF on June 23, 2021, 11:47:16 pm

At that price, I would sooner have the Siglent SPD1305X

Defpom did a review: ...................

Then he ordered the 16V 8A unit from us.

Thread:
https://www.eevblog.com/forum/testgear/new-spd1168x-siglent-psu/

MarkF · « **Reply #20 on:** June 24, 2021, 04:20:32 am »

Quote from: tautech on June 24, 2021, 02:03:28 am

Quote from: MarkF on June 23, 2021, 11:47:16 pm
At that price, I would sooner have the Siglent SPD1305X

Defpom did a review: ...................
Then he ordered the 16V 8A unit from us.

Thread:
https://www.eevblog.com/forum/testgear/new-spd1168x-siglent-psu/

Yes, I remember watching his reviews of both models and that he bought one of them.

Some day I'll break down and get a Silent.
However, I have four of the little HP-6216A power supplies. They were in my electronics lab in college and I instantly fell in love with them. Only are 0.5 amp but you can parallel or series them together.

Old Printer · « **Reply #21 on:** June 24, 2021, 01:05:58 pm »

[/quote]
However, I have four of the little HP-6216A power supplies. They were in my electronics lab in college and I instantly fell in love with them. Only are 0.5 amp but you can parallel or series them together.
[/quote]

I have several of these as well, they are great for light duty bench work and can be found on eBay for $30-$50 if you wait a bit. Dead quiet, stackable and compact. I am working on an add-on digital volt & amp meter as the analog meter scales are a bit small fo my old eyes 😀

Hydron · « **Reply #22 on:** July 16, 2021, 10:03:43 am »

Can anyone confirm if the turn-on spike occurs with any meaningful load attached? Spike seems very short, so I'm wondering a) if it's even real and b) if it has any significant energy. I can live with the OCP/OVP being worthless - never really use these anyway, so this seems to be the biggest concern left.

John B · « **Reply #23 on:** July 16, 2021, 08:45:16 pm »

Quote from: Hydron on July 16, 2021, 10:03:43 am

Can anyone confirm if the turn-on spike occurs with any meaningful load attached? Spike seems very short, so I'm wondering a) if it's even real and b) if it has any significant energy. I can live with the OCP/OVP being worthless - never really use these anyway, so this seems to be the biggest concern left.

Just a warning that from the videos I saw, it looks like the voltage at the output doesn't update immediately with turning the rotary encoder. Owners of the unit can confirm it's functionality, but that was enough to turn me off buying it.

GeorgeLouis · « **Reply #24 on:** June 14, 2022, 02:25:54 pm »

Will this work in 120V 60Hz AC power line. Is there any way to change it's input voltage range.


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Author Topic: Inside the Owon P4603/P4305 linear PSU (Read 19324 times)

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