First impression and problem with MCH K305D supplies - Page 1
Forum section: electronics / testgear

author: dimkasta
author_rank: Regular Contributor
timestamp: January 23, 2017, 03:03:51 pm
content: I just received an MCH K305D supplyhttp://www.ebay.com/itm/141991049197I 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?

author: tautech
author_rank: Super Contributor
timestamp: January 23, 2017, 07:49:55 pm
content: Quote from: dimkasta on January 23, 2017, 03:03:51 pmYep, here:https://www.eevblog.com/forum/testgear/cheap-variable-switching-power-supply/

author: nctnico
author_rank: Super Contributor
timestamp: January 23, 2017, 08:01:17 pm
content: It quickly turned into a hacking project:https://www.eevblog.com/forum/testgear/cheap-variable-switching-power-supply/msg676967/#msg676967I 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'mnotveryhappywith it. I also have the 30V 10A version but it is still waiting for the necessary safety and EMC updates.

author: dimkasta
author_rank: Regular Contributor
timestamp: January 23, 2017, 10:40:09 pm
content: Thanks guysI 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

author: nctnico
author_rank: Super Contributor
timestamp: January 23, 2017, 11:07:42 pm
content: 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.

author: dimkasta
author_rank: Regular Contributor
timestamp: January 26, 2017, 09:53:20 am
content: 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?

author: dimkasta
author_rank: Regular Contributor
timestamp: April 28, 2017, 09:51:17 am
content: 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

author: marketta49
author_rank: Newbie
timestamp: November 09, 2017, 10:34:20 pm
content: 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

author: marketta49
author_rank: Newbie
timestamp: November 10, 2017, 01:59:42 pm
content: okaythank you and apologize for the double post