Longwei PDS-3010G

[Aldo22]

I bought something cheap again. 

A Longwei PDS-3010G 30V 10A PSU for CHF 39.- (USD $44.50) delivered.
I haven't found any cheaper 300W PSU.

I didn't expect much but it works so far.

PROS

• 4-digit display. Volt, Ampere and Watt.
• Coarse and fine knobs for A and V separately.
• USB charging socket.
• GND (PE) output.
• It reaches 30V and 10A with reserve (31.7V / 10.24A).
• No overheating problems so far.

NEUTRAL

• The fan is always running, so it's not "smart", but it is very quiet and runs at low speed.
  This is probably more pleasant than a fan that keeps turning on and off.

CONS:

• Precise adjustment (4 digits) is difficult even with the "fine" knobs.
• The accuracy is not so good that it would require a 4-digit display.
• In the lower ampere range, the setting cannot be made without a multimeter. You can set the current limit so that you can, for example, power an LED without a resistor, but the display will then be at 0. It can not show as low as 20mA.
• There is no on-off button for the output, but I have not seen any overvoltage when switching on.
• Due to the design (SMPS) there is of course some noise, but I think it is within the normal range (20mV RMS in the example "noise.png").
  I'll try to reduce it as shown in the video when the capacitors are here.
  

A bit concerning: Whether the rear metal parts are grounded (PE) depends on the screw in "screw.jpg".
If this (accidentally) makes electrical contact with the back cover, the parts are grounded, otherwise not.
I scraped off the paint there to ensure contact.

“You get what you pay for”, but yes, it does what I expected and trying to improve cheap stuff is always fun.   

Board Rev:20230518

[madires]

A bit concerning: Whether the rear metal parts are grounded (PE) depends on the screw in "screw.jpg".
If this (accidentally) makes electrical contact with the back cover, the parts are grounded, otherwise not.
I scraped off the paint there to ensure contact.

I would add a star washer.

[Aldo22]

I'd would add a star washer.

Yes, that's what I plan to do.

[tautech]

I bought something cheap again. 

A Longwei PDS-3010G 30V 10A PSU for CHF 39.- (USD $44.50) delivered.

NEUTRAL

• The fan is always running, so it's not "smart", but it is very quiet and runs at low speed.
  This is probably more pleasant than a fan that keeps turning on and off.

Now load it to 50% and expect the fan to spin up some. 

[Aldo22]

Now load it to 50% and expect the fan to spin up some. 

Hmm, so far I've never heard the fan reacting in any way. It always spins at the same speed.
But it keeps the device cool enough, even under prolonged load.

[bobale]

A Longwei PDS-3010G 30V 10A PSU for CHF 39.- (USD $44.50) delivered.

Where did you get it for such a low price?

[orzel]

Where did you get it for such a low price?

Probably on the official longwei store on ali ?
https://www.aliexpress.com/item/1005005489733374.html

[Aldo22]

Probably on the official longwei store on ali ?

Right. There was a sale around Christmas (USD 44.64)

[bobale]

Unfortunately, it is much more expensive now with the shipping included.

[orzel]

Unfortunately, it is much more expensive now with the shipping included.

Weird, the shipping seems quite high. From here (France) it's 52.21€ with "free" shipping, and including 20% taxes.

[Aldo22]

Yes, prices change from country to country.
It's an opaque science. 
For the EU, VAT is included in the Aliexpress price.
Not for Switzerland, for example. For postal imports, you only pay VAT from a total amount of CHF 65.
I don't know for Serbia.
It's difficult to compare.

[Aldo22]

Unfortunately, it is much more expensive now with the shipping included.

Doesn't it show you any shipping options when you click on "Shipping"?

[Aldo22]

After soldering in resistors and capacitors (47nF / 100V), the noise looks a little better (compare with the screenshot above).
Of course it is not perfect.

[orzel]

After soldering in resistors and capacitors (47nF / 100V), the noise looks a little better (compare with the screenshot above).

Ah, impressive. Check that the mosfets don't get too hot because of the change though.

[Aldo22]

Ah, impressive. Check that the mosfets don't get too hot because of the change though.

Thank you.
Yes, I ran it with a 100W load for a while.
It didn't get any warmer than before, as far as I could see with the pyrometer.
But it's still an SMPS. It still has some noise. It is somewhat better than before.