First impression and problem with MCH K305D supplies

[dimkasta]

I just received an MCH K305D supply

http://www.ebay.com/itm/141991049197

I am still waiting for the second one (I asked them to be shipped separately to avoid having to get them through UPS or FEDEX and have to pay the ridiculous fees.

The main problem I found is that the supplied cable's earth lead is not connected!!!!!!!

I have lots of cables around, so no problem. But still, another indication that people must be careful with those cheap devices.

I did not have much time to do deep testing.
Just a quick earth test for the chassis, a quick test that no live wire goes to the chassis, a quick look inside for something obviously wrong and some quick voltage verification with a DMM.

Apart from the faulty cable all seems to work ok.

Anyone has experience with them? Anything else I should test for?

My guess from the separate earth lead is that they are floating and can be connected in series right?

[tautech]

I just received an MCH K305D supply



Anyone has experience with them?

Yep, here:
https://www.eevblog.com/forum/testgear/cheap-variable-switching-power-supply/

[nctnico]

It quickly turned into a hacking project:
https://www.eevblog.com/forum/testgear/cheap-variable-switching-power-supply/msg676967/#msg676967
I use mine with the ground connected to the earth pin because the leakage of the mains filtering capacitors causes several tens of volts at the output. I started to feel that and it could blow up electronic circuits! All in all I'm not very happy with it. I also have the 30V 10A version but it is still waiting for the necessary safety and EMC updates.

[dimkasta]

Thanks guys

I have seen that thread.
In fact nctnico's posts were the reason I did not get the LW, even though I would prefer the binding posts.

Fortunately my MCH does not seem to suffer from all those safety issues.

I still have to check it with a scope though.

Here s a photo of the innards. You can see the protective sleeves and the ground wires.

One thing that was bothering me was a rattling noise at the back. Thankfully, it was just a spare fuse in the fuse holder... Nice

[nctnico]

Wow!  Would the manufacturer be looking at EEVblog? It is like they addressed all my concerns in your unit which otherwise looks identical to the one I have.

[dimkasta]

One thing I do not like about them is that they do not display the current setting when you turn the knob.

Do you guys know of any mods that might allow that?

[dimkasta]

Anyone having issues with the iec sockets?

They seem very loose and I have issues with cables not fiting tightly enough.

I think I'll just replace them

[marketta49]

Post removed as it is a copy of this new topic: https://www.eevblog.com/forum/testgear/problem-power-supply-tech-star-k3010d/msg1345619/#msg1345619

[marketta49]

okay
thank you and apologize for the double post