Bench Power Supply 30V/10A Review - LongWei LW-K3010D

Review of a US$40-50 Switch mode bench power supply.

LongWei LW-3010D
LongWei LW-K3010D

[TheStuffMade]

I have a follow up video on how to fix the noise issue with a few basic components:

[grahamhall]

Had one of these for two years now, its a great PSU.

[mscir]

I just got one of these used on ebay $36 incl. shipping. So far it's working great. Your review is very well done. Thank you.

[jamesdcuk]

Thanks the review! I've ordered one. You've saved me some cash because I'll be able to use this over the missing power supply that my robot lawnmower manufacturer wants £180 for!!

[robertgoodwin]

Thanks for the review, it was very informative. I have just ordered one from BG to use as a general bench supply for low power digital and analogue circuits. I might be doing your switching noise fix when it arrives... but first I'll be changing those output terminals!

[zerodegrekelvin]

Nice review! The noise you show on the scope is very useful 8-)

[tinkmarshino]

Dang.. very complete look at a cheap power supply.. I am gonna have to look at your other vid's thanks.. carry on!

[falconer]

My one worked good for a year charging small batteries, model train testing and general light use. Charging a 18650 lithium ion when " BANG " . One of the large capacitors blew its end off. Replaced capacitors but it only reads to 1.5v then falls away. I am purchasing another make of power supply for a replacement.

[Lkabouter]

Just want to add something that I saw in my own model of this power supply :
Check the earth wiring ! My one had its metal case not connected to earth at all ! The earth wiring was bad : from the rear mains socket the earth wire was only going to the pcb and via a pcb trace it was supposed to touch a metal stud which on turn was screwed to the rear of the case. But this had no connection at all because of the thick paint on the case surface !
Also the front earth terminal should have a better earth wire coming directly from the rear mains socket and not via a pcb trace.

So here is what I did to improve the earth wiring :
1. make an earth wire from the rear mains socket directly to the metal case with an eye terminal fastened by a nut to a new and longer bolt in the rubber foot near the mains socket and scartch off some paint there for a good connection.
2. Leave the wire from the rear mains socket to the pcb.
3. make an earth wire from the mains socket directly to the earth output terminal at the front.
4. scratch off some paint on places where the metal cover is screwed on the metal case. (both sides) This ensures a good electrical earth connection everywhere and also a better shielding.

[guanilee]

I have the same one, and I've had problems with the included wires (banana to clip, black and red). It could handle only about 3 amps in my case. Thanks for the great review!

[karlschwab]

Excellent review! I guess that I don't understand the requirement to set the current. Thanks again.

[hbk_]

Sir i need your help because my Longwei power is same ad yours but the Auxillary Fan i dont know if its working or No? Please Tell me if your Power Supply Fan Is turn On everytime you use it or you need to wait an Hour before it will Automatically Turn On Please answer me sir🙏🙏🙏

[Aaron]

Thought I was listening to JoergSprave testing a cheap psu. I kept waiting to hear a hearty "AH HAHA!"

[jorgefernando]

Could you please film all the modifications that you will make?

[romydeleon]

A great and very thorough review. I just got one for my self to use mainly for charging batteries and other DIY projects. The single turn Current Control Pot as you demonstrated is very hard to set especially in low settings, i.e. micro amps. Thinking abut replacing it with a multi-turn pot. Read from other users that they used the WXD3-13 2W 10K style pot. Will this be a proper replacement? Looking at the three wires can you comment which wires goes were on the replacement pot? Thank you.

[paco_rider]

I think it's going to be ok for some diy projects and a battery charger

[twofpv]

Hey, just got mine today. I am using it for testing and repair of diy quadcopter components. In your opinion do you think this will be good enough for such things? Thanks for the vid and info

[yurkshirelad]

Is it too noisy for Aurdino/ESP8266/ESP32, 3.3V/5V sensors and basic circuits?

[RingZero]

Great video - Liked the heatsink. Any link to buying the heatsink?

[xraykadiddlehopper]

Question on the LED lights. I’m using this currently to top off a 24v LiFePo battery which has a max charge current of 28.8v.
I set the voltage at 28.8 and 10a to charge but the red LED for c current comes on. If I lower the voltage it lights the c voltage LED. I need 28.8v to charge to full but would like the current to taper when approaching full. With c current the current doesn’t taper down is that correct? If I turn the voltage down for c voltage it isnt enough to top off the battery.
I’m very much a novice and would like to understand the operation of this power supply
Thanks