Longwei PDS-3010G - Page 1
Forum section: electronics / testgear

author: Aldo22
author_rank: Super Contributor
timestamp: January 09, 2024, 06:09:58 pm
content: 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.PROS4-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.NEUTRALThe 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 thevideowhen 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

author: madires
author_rank: Super Contributor
timestamp: January 28, 2024, 02:06:24 pm
content: Quote from: Aldo22 on January 09, 2024, 06:09:58 pmI would add a star washer.

author: Aldo22
author_rank: Super Contributor
timestamp: January 28, 2024, 02:22:41 pm
content: Quote from: madires on January 28, 2024, 02:06:24 pmYes, that's what I plan to do.

author: tautech
author_rank: Super Contributor
timestamp: January 28, 2024, 07:48:54 pm
content: Quote from: Aldo22 on January 09, 2024, 06:09:58 pmNow load it to 50% and expect the fan to spin up some.

author: Aldo22
author_rank: Super Contributor
timestamp: January 28, 2024, 08:49:07 pm
content: Quote from: tautech on January 28, 2024, 07:48:54 pmHmm, 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.

author: bobale
author_rank: Contributor
timestamp: January 31, 2024, 05:14:36 pm
content: Quote from: Aldo22 on January 09, 2024, 06:09:58 pmWhere did you get it for such a low price?

author: orzel
author_rank: Regular Contributor
timestamp: January 31, 2024, 05:24:02 pm
content: Quote from: bobale on January 31, 2024, 05:14:36 pmProbably on the official longwei store on ali ?https://www.aliexpress.com/item/1005005489733374.html

author: Aldo22
author_rank: Super Contributor
timestamp: January 31, 2024, 05:46:43 pm
content: Quote from: orzel on January 31, 2024, 05:24:02 pmRight. There was a sale around Christmas (USD 44.64)

author: bobale
author_rank: Contributor
timestamp: January 31, 2024, 07:56:57 pm
content: Unfortunately, it is much more expensive now with the shipping included.

author: orzel
author_rank: Regular Contributor
timestamp: January 31, 2024, 08:04:25 pm
content: Quote from: bobale on January 31, 2024, 07:56:57 pmWeird, the shipping seems quite high. From here (France) it's 52.21€ with "free" shipping, and including 20% taxes.

author: Aldo22
author_rank: Super Contributor
timestamp: January 31, 2024, 08:27:41 pm
content: 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.

author: Aldo22
author_rank: Super Contributor
timestamp: January 31, 2024, 08:39:38 pm
content: Quote from: bobale on January 31, 2024, 07:56:57 pmDoesn't it show you any shipping options when you click on "Shipping"?

author: Aldo22
author_rank: Super Contributor
timestamp: February 02, 2024, 02:28:58 pm
content: 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.

author: orzel
author_rank: Regular Contributor
timestamp: February 02, 2024, 10:06:50 pm
content: Quote from: Aldo22 on February 02, 2024, 02:28:58 pmAh, impressive. Check that the mosfets don't get too hot because of the change though.

author: Aldo22
author_rank: Super Contributor
timestamp: February 02, 2024, 10:36:06 pm
content: Quote from: orzel on February 02, 2024, 10:06:50 pmThank 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.

author: edmaul69
author_rank: Newbie
timestamp: August 26, 2025, 07:23:24 am
content: Question, do you live in a place that uses 220v electricity? I ask because people have found their fine tuning at lower amperage problems was because they didnt switch the switch on the back to 110v

author: Aldo22
author_rank: Super Contributor
timestamp: August 26, 2025, 08:14:29 am
content: Quote from: edmaul69 on August 26, 2025, 07:23:24 am230V/50 Hz

author: Phil1977
author_rank: Frequent Contributor
timestamp: August 26, 2025, 08:33:14 am
content: Just as a safety advice: If you don't trust the primary/secondary insulation of these devices you can connect the output to PE - that way the RCD kills the power if any insulation failure occurs.Did you coarsely check the creep distances on the PCB, the design of the transformers and the type of Y-capacitors used? Probably it´s okay, but personally I always check this at "self-imported" power supplies.I regularly use these things as universal battery chargers. After long operation at 10A the terminals sometimes get to hot, sometimes it´s advisable to re-tighten the cable connectors. You´re right, you get what you pay for but in this case you can get quite a lot for little money.