Korad KA3005D Digital variable power supply (bought Nov 2017)

[Terry01]

I'll open mine up later today and post some images of the Tenma version for comparison. I did open it when I got it for a quick nosey but can't remember off hand if it was a decent heat sink or not.
I've had mine around 12 to 18 months, I got it from Farnell element 14. It'll be good to see if there are any differences inside or if they are exactly the same.
It's always good to have a reason to take things apart! 

I am loaded up with the flu and cannot be bothered stripping out my PSU! I will post said photos in the next day or 3 when i'm feeling more enthusiastic. Crap! 

[stj]

you need to sterilise your bloodstream.
i like vodka myself.
 

[tooki]

factory's churn out power cords for lots of country's - they dont each come from a seperate source.

Well yes. But what makes you think that there's only one factory making power cords? (And that those factories only make one grade of cord.)

anyway, it looks like you can spot them with an ohm-meter.
so that makes it simple to check.

A wise precaution in any case!!!

[lt_cdr_data]

Hi, the light blue resistor R3 is blown on my device (mounted on the upper edge of the board close to the fan connector) could you tell me it's value, so i could replace it. TIA

[Mr. Scram]

Hi, the light blue resistor R3 is blown on my device (mounted on the upper edge of the board close to the fan connector) could you tell me it's value, so i could replace it. TIA

Can you show it in a picture?

[Terry01]

Hi, the light blue resistor R3 is blown on my device (mounted on the upper edge of the board close to the fan connector) could you tell me it's value, so i could replace it. TIA

R3 is.... 10 Ohms 1% buddy.

[lt_cdr_data]

Thank's dude, could you guess the wattage of it as well? Cause I have really no clue how it can burn off like it did in my case. Did not found any schematics to read off it's purpose in the circuit. BR

[Terry01]

Thank's dude, could you guess the wattage of it as well? Cause I have really no clue how it can burn off like it did in my case. Did not found any schematics to read off it's purpose in the circuit. BR

I'd guess 3W.

[ziplock9000]

As for why the fan pushes the air out - it's so the newly warm air isn't blown over the internals.

If you are more worried about pulling dust into the enclosure then you could turn the fan around so it blows inwards and magnetically stick something like this to the back.
https://www.overclockers.co.uk/demciflex-dust-filter-80mm-square-black-white-cm-000-df.html

All my PC fans blow inwards with these over them to create positive pressure in the case so no dust enters via all the little holes, grills, etc.
Quick wipe with a lightly damp cloth or the hoover every few days and the inside of my PC case is still spotless after ~6 years.

That's interesting, and after 6 years I cannot question you on if it works well or not (obviously it does), but if all of the fans blow inwards, where does the air escape?
My understanding is that we're not supposed to have pressure inside of the case, but rather keep the airflow as good as possible (so that there is no time for heat to accumulate inside of the case). Dust can be reduced with filters, but obviously filters will also reduce airflow to a point, but a positive effect is that also noise could be slightly reduced.

At least with the standard configuration, I've noticed most effect with back and back top fans blowing out, for me those are the most important fans to have, and to have good airflow capabilities. I've noticed much less effect with added side fans or front fans (with front fans blowing in, and side fans depending on the side). This will depend on the case of course. Some cases just offer better cooling with the same amount of fans than others.

This is a "solved" problem and not really open for debate with PC cases and hasn't been for quite a while.
The best case setup has fans pushing air in and pulling air out. The ones pushing air in should have more power then the ones pulling out to create positive air pressure and reduce dust (considerably). These fans have an air filter attached. The fans pulling air out should be near the CPU heatsink and create a clean path from the fans pushing air in. You can add more fans that support this arrangement that target specific areas in the case, for example moving air from the GPU into the in-out stream, but they are all variations on this theme.

[ziplock9000]

Thank's dude, could you guess the wattage of it as well? Cause I have really no clue how it can burn off like it did in my case. Did not found any schematics to read off it's purpose in the circuit. BR

I'd guess 3W.

So do you consider this still to be the best price/performance cheap digital bench power supply in the UK?

[Terry01]

Thank's dude, could you guess the wattage of it as well? Cause I have really no clue how it can burn off like it did in my case. Did not found any schematics to read off it's purpose in the circuit. BR

I'd guess 3W.

So do you consider this still to be the best price/performance cheap digital bench power supply in the UK?

I don't know about the "best" in the UK but a very good hobby PSU in my limited opinion. To be the "best" you have to look at so many different things I know too little about.
There are so many to choose from and I don't know enough electronics wise to say one is better than another for whatever reason.

I know I still love mine after a couple years of good solid use. It's still quite accurate and the fan doesn't squeak or rattle so it's still very quiet.
All the safety features still work as they should and that part I have tested to the limit i'm not too proud to admit! 

I would certainly recommend it to anyone looking to buy 1. I have no complaints at all with mine. I found it easy to use and learn how to get the most from it and found it very forgiving as I made lots of newby mistakes. There are a few guys here on the forum have them too and can usually tell you how to fix it if needed or open theirs to help get parts numbers or whatever.

At a guess it has to be up there with the best surely.

[ziplock9000]

One major thing that worried me about that one, even for hobby use is the spike/inrush when it's turned on. Some people were saying they were substantial. Have you tested yours on a scope?

[Terry01]

One major thing that worried me about that one, even for hobby use is the spike/inrush when it's turned on. Some people were saying they were substantial. Have you tested yours on a scope?

I have had it on my scope but that was a while ago but i can't remember anything that jumped out at me. I can't even remember why i had it hooked up to start with, just tinkering with something else i think so hooked the PSU up too as it was there and I hadn't done it before. I will certainly hook it up the next time i have my scope out. I keep it boxed up when i'm not using it as i am a bit tight for bench space right now.
I'll post here what i find.
I know that i have never fried anything due to spikes on start up before.
I have the Tenma version so it would be good to check if they are exactly the same or just a straight re-badge or if anything is different inside.

It might be a good idea to get some decent photos up of both units and see if there are any differences between them.