Author Topic: Korad KWR102 power supply  (Read 4217 times)

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Offline knudchTopic starter

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Korad KWR102 power supply
« on: October 25, 2021, 03:34:46 pm »
I have just got this one on my table
1306880-0" alt="" class="bbc_img" />

30V - 30A, max 300W so called wideband PSU
Seams ok for the price (275 euro incl shipping)
RS232/RS485/LAN communication
First test is ok...stable and no stranges behavior
There are 2 fans inside, but not much noise from them under load, no load, no noise at all.
Documentation is some what "simple" 15 pages manual...leaves a number of questions.
Accessories: Cables, Mains, USB, RS232 DB9, heavy test leads, software CD.
Under load there is a humming from the enclosure......in quiet places and for long time ...annoying   
UI you need to get used to !
But every thing is working so far.

Was actually looking at something "bigger" like Siglent SPS5042X 40V/60A/720W or ITECH IT6723C 32V/110A/850W
But I considered that those cases where I need such current is limited to 12V/230V power inverter testing and for that I bought a brand new server supply 13,5V/100A for 50euro.
Of course are siglent/itech properly another quality, but also another price level.

« Last Edit: October 25, 2021, 07:59:21 pm by knudch »
 

Offline knudchTopic starter

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Re: Korad KWR102 power supply
« Reply #1 on: October 25, 2021, 08:11:15 pm »
Have tested the software which came with the unit
Nothing fancy but ok for testing remote operation.
Can do simple list based jobs.

Tested setting and read-back accuracy, is ok, within spec's as far I can check.

The plugs on the front shall be un-sharped....when you plug in a test lead it's sound not nice and I can see a bit of metal parts.
Can be un-sharped with a drill of fitting size.

Inside it is compact but looks ok, big components are glued to prevent getting loose due to vibration

Generally it meets my expectations in relation to price/performance
 

Offline radiolistener

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Re: Korad KWR102 power supply
« Reply #2 on: October 26, 2021, 06:13:00 am »
I'm not sure, why it has "max 10 A" label near output terminals? Because PSU is marked as 30 V / 30 A
 

Offline knudchTopic starter

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Re: Korad KWR102 power supply
« Reply #3 on: October 26, 2021, 06:22:05 am »
Max 10A on front terminals, rear terminals 30A
Typical for PSU with more than 10A
Front terminals are "normal" plug/binding post
Rear is screw terminals
« Last Edit: October 26, 2021, 06:27:00 am by knudch »
 

Offline radiolistener

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Re: Korad KWR102 power supply
« Reply #4 on: October 26, 2021, 06:28:42 am »
Found this review:
 

Offline knudchTopic starter

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Re: Korad KWR102 power supply
« Reply #5 on: October 26, 2021, 07:02:37 am »
Yes I saw that before I ordered it.

I think he has not played a lot with, he is surprised in some situations.

As a I wrote, documentation is very short/incomplete and the UI, you shall get used to it  :)

But it is doing its job, technical ok.
I think you get a lot for that price
« Last Edit: October 26, 2021, 09:02:53 am by knudch »
 

Offline radiolistener

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Re: Korad KWR102 power supply
« Reply #6 on: October 26, 2021, 08:16:52 am »
knudch

what is the max current it can provide for 12V and for 24V? (through high current terminals on the back panel)
 

Offline knudchTopic starter

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Re: Korad KWR102 power supply
« Reply #7 on: October 26, 2021, 09:02:04 am »
Divide 300W with voltage = max current
Absolute max current is 30A which is at 10V

https://www.reichelt.de/index.html?ACTION=7&LA=3&OPEN=0&INDEX=0&FILENAME=D500%2FKWR-SERIES_MAN-EN.pdf
« Last Edit: October 26, 2021, 09:12:35 am by knudch »
 

Offline knudchTopic starter

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Re: Korad KWR102 power supply
« Reply #8 on: October 28, 2021, 08:18:17 pm »
Played a little with remote operation

The SW (windows) that came along work just out of the box (WIN 10)

I normal use Linux so I tried my luck there ;)

No LXI support

It seems that it support only UDP "connections"

But it works..just send the command

Only thing which is a little unusual in case of retrieving data from the device.
The port number which the computer shall send from need to be same as the receive port number on the KWR102 (can be defined), so it will always answeer on the same port which it receive on.

Normal device responds to that port number where there is send from, which must often are random
 

Offline WR3

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Re: Korad KWR102 power supply
« Reply #9 on: December 16, 2021, 03:37:56 pm »
I have model KWR103 (also known as TENMA 72-13360 on Farnell)

Here is a turn ON 12V, 50mA, no load:
1350941-0

Turn ON 12V, 3A, no load
1350947-1

60V 20mA into 2V LED
1350953-2

60V 20mA into 9x3V LED
1350959-3

60V 1A into 9x3V LED V+I
1350965-4

Same thing in high res.mode
1350971-5

Noise at 12V 50mA with modification inside (later in post). I know that is not how noise is measured, but that is noise I will see if I have a device under test!
1350977-6

Noise at 60V 50mA into 9x3V LED with modification
1350983-7

First of all I am happy with build quality, performance and stability of this power supply, but there are some problems:

Big problem 1: If you load memory 5, enable the output and then turn the knob the settings change to 60V 5,4A, thankfully the output is disabled. Be weary not to enable the output again or you will probably destroy DUT.

Problem 2: Output button and indication is very unnoticeable. For now I changed the LED to a powerful blue one and add a mark over power on button. The plan was to add LED above the button, but there is a stud behind. It would be nice if the output button would be clear as memory ones and have a two color LED under it. I will probably place 5x2mm LED in a vent slot under button.
1350989-8

Annoyance 1: No power display.

Annoyance 2: Very fast voltage cursor reset. Lets say you want to take manual measurements every 1V. You set to first voltage, and when you are writing down measured current the cursor resets. You have to turn cursor on again before spinning encoder to increase voltage.

Annoyance 3: There are two fans inside which are temperature controlled, but they are not tuned...If you have a small load for a long time the fans will turn ON and then ramp up and up and up. One of the future modifications will be to force rear fan to always run at very slow speed.

Annoyance 4: No number pad and form factor. I know single power supplies mostly have this stand up form factor, but I would put this power supply into the same form factor as their electronic load KEL103 with basically the same buttons. The cherry on top would be to have a A, mA, V and mV buttons as does Rigol. Then you can simply type 5+V+5+0+mA to set the output to 5V 50mA instead of selecting current and voltage and move the cursor around.

Annoyance 5: Relatively high output capacitance. 330uF+ 2x100uF (the 30V version probably have even higher values)

Wire mod: There is a short wire from the output transistor to the rear terminal, but there are two long wires that go from there to the front terminals under whole power supply. The problem is these wires are 10cm apart and pick up noise from power supply and digital board. They were just long enough to twist them together and place both in a single tube they were originally in. I think there was a noise decrease, but I have no measurements. I just did this while I was in there.  Beware that You have to basically disassemble 3/4 of a power supply to make this mod.
1350935-9

Note: There are 3 main boards, all connected together with headers and 3 support boards. It will be a pain to fix if something dies in the future.
« Last Edit: December 16, 2021, 03:43:58 pm by WR3 »
 
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Offline WR3

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Re: Korad KWR102 power supply
« Reply #10 on: December 16, 2021, 05:09:55 pm »
Well... I just made the fan modification. You just take the main cover off and then you can access it from the side.
Fans are always connected to the +12V, so in my case I only connected 2x460R in parallel to the ground bypassing the fan control circuit.

Korad fans are laud, so if you want more silence you have to change them.

 

Offline knudchTopic starter

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Re: Korad KWR102 power supply
« Reply #11 on: December 17, 2021, 07:25:55 am »
Few comments:
(KWR102)

Noise: approx 70mVpp at 12V/1.5A

Fans: when idle (after high load), I can hear it but not critical is total overruled by my SDS2104x+
At high load humming is surprisingly loud, FANS sound is acceptable for high load situations
 
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Offline edavid27

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Re: Korad KWR102 power supply
« Reply #12 on: May 04, 2023, 11:26:08 am »
Hello,

i have ordered the power supplies but there was no CD in the package.
Could you share the tools please ?
it will be helpful.
thank you
 

Offline mawyatt

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Re: Korad KWR102 power supply
« Reply #13 on: May 05, 2023, 11:29:55 pm »
Anyone have success with the Dynamic Setting Function or the Voltage & Current Slope Setting Function on the KWR102 or 103?

Best,
Curiosity killed the cat, also depleted my wallet!
~Wyatt Labs by Mike~
 

Online tooki

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Re: Korad KWR102 power supply
« Reply #14 on: May 06, 2023, 12:52:30 am »
Hello,

i have ordered the power supplies but there was no CD in the package.
Could you share the tools please ?
it will be helpful.
thank you
https://www.koradtechnology.com/companyfile/6/
 

Offline mawyatt

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Re: Korad KWR102 power supply
« Reply #15 on: May 06, 2023, 02:42:50 pm »
We're evaluating the KWR102 for a colleague/client that requires a max ~25A capability at ~12VDC for production product testing. Because funds are short we had to consider a lower tier Power Supply for their use as well as ours (we are developing custom controllers for their future products).

After reading the various reviews and user experiences we decided to give Korad a try and purchased a KWR102 which may meet the needs for output levels and as a Bench Supply for the controller development, but should at least be acceptable for the production testing.

Initial impression after Dave's famous "Take it apart!!" addiction (which we were also born with), as this supply is well built considering the price/performance ratio, you can probably gather that from the earlier image posts by WR3 & knudch. Korad also provides nice flexible #10AWG long test leads with spade lugs, USB and RS232 NULL cables, and a detailed test verification sheet with equipment utilized (Fluke 8846A, ITECH IT8512, Rigol MSO5204), date and a real signature :-+

We did a few measurements to check things out and the supply can provide the stated current levels at the voltage levels shown within the 300W power constraints. The voltage noise levels are remarkably low, well below the specs, and don't jump up much as output current increases, altho we did discover some random low frequency jumping around when the fan(s) engage. The fans are loud at full force with some case "buzzing" occuring but acceptable (no buzzing) at low levels and the units seems to have a very long time constant (minutes) that cycles the fans even without a load sometimes.

The output voltage levels were spot on across the entire range with a quick unloaded measurement, and we mean spot on as 10V is 10.000058V (40uv SD), 1V is 1.00010V (8uV), 20V is 20.00036V (13uV), these will wander some as temp changes with fans and the SD gets much higher above 20V, >100uV. We didn't measure current levels in detail other than checking the high end limits, but the readings seemed to agree well with the electronic load (SDL1020X). A quick check of the load regulation at the PS terminals is very good, we haven't tried the remote sense capability yet tho.

The provided manual is not thorough and requires some time to work thru even tho it's short. The files provide on the CD evidently are not shown on the Korad website, and we have no means to read a CD! We haven't been able to get the Slope and Dynamic Setting Functions to work.

Remote control by USB or RS232 (haven't tried LAN) doesn't work with VISA but does with a Terminal like TeraTerm. The commands shown in the manual can be truncated by removing the ID portion, as example manual shows VSET05:12.5 which can also be VSET:12.5. 

Anyway, this KWR102 seems like a good supply, well built & small, excellent performance and good value considering the performance/price/specs. Hopefully someone has been able to get the Slope and Dynamic Setting Function to work, and can report such.

Edit: We were able to get the Slope and Dynamic Setting Functions to work, this was by entering the details from Remote rather than Front Panel. VSLOPE and ISLOPE work as expected with V or I per 100us slope, and the Dynamic LIST command with 00 entered the number of loop cycles and the number of individual Voltage, Current, Slope (V/100us), and Time between updates. Then the LIST command with 01, 02,03 and so on enters the previous mentioned parameters for each update point.

Best,
« Last Edit: May 07, 2023, 03:02:29 am by mawyatt »
Curiosity killed the cat, also depleted my wallet!
~Wyatt Labs by Mike~
 


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