Linear PSU and low-ESR vs normal capacitors.

[5U4GB]

Well there's not much information about this power supply on internet.
Can't find any schematics or anything else.

It's a tweak of the very popular and widely-used (and analysed) KA3005D/P, see the previous post, so presumably anything for the KA3005 also applies to the KKG305.

[xKertx]

Would you consider posting photos of the internals to one of the KA3005D/P threads?  It's been mentioned there but no-one knows much about it or how it compares to the more mainstream KA30xx series.

Yeah, why not. I might do a small review some day when i have spare time.

[Solder_Junkie]

I have a home made bench power supply that I built around 48 years ago. I still use it and I haven’t replaced any capacitors. It is 25V, 3A and variable Voltage/current. The caps I used were those I had to hand, while not particularly high grade parts, they weren’t junk either.

Personally, I wouldn’t rush into replacing any capacitors unless they show signs of leaking or bulging.

SJ

[5U4GB]

I have a home made bench power supply that I built around 48 years ago. I still use it and I haven’t replaced any capacitors. It is 25V, 3A and variable Voltage/current.

LM723 and a 2N3055?  Bonus points if the former was in a TO-74.

[Solder_Junkie]

No, it’s the ETI-131 from Electronics Today International magazine published in April 1976.

The ICs are CA3130 in metal cans. There are zip files to the original article on this page:

https://www.thebackshed.com/forum/ViewTopic_mobile.php?FID=4&TID=4422&PID=0

I now use a dual readout LED meter in place of the original analog meter, but other than changing the meter, it hasn’t been touched since making it. A thoroughly reliable design using almost jelly bean parts!

SJ

[5U4GB]

No, it’s the ETI-131 from Electronics Today International magazine published in April 1976.

The ICs are CA3130 in metal cans. There are zip files to the original article on this page:

https://www.thebackshed.com/forum/ViewTopic_mobile.php?FID=4&TID=4422&PID=0

For people who want a direct link to the scanned PDF, you can get it here, page 74.  It does have the obligatory 2N3055, alongside a flying-wires diode bridge and filter caps and a metal-bashing case and heatsink that you bolt together from bits of aluminium sheet.

[dobsonr741]

There is something magical in these ‘70 and ‘80 electronics magazines. Telling that everything is possible by doing it by your hands.

Same still applies today, just to barriers are higher. Thinking of training a 60B LLM.

[xKertx]

Would you consider posting photos of the internals to one of the KA3005D/P threads?  It's been mentioned there but no-one knows much about it or how it compares to the more mainstream KA30xx series.

https://www.eevblog.com/forum/testgear/korad-kkg305dkkg305p/

[coppercone2]

I put the best electrolytics money can buy reasonably into alot of my bench power supplies I restored and there is no problem.

I agree with what david hess said. Don't know what would happen with polymer capacitors though. I save that for my own designs where I test the system from component to component

[wraper]

Using low ESR caps where they are not needed is a waste of money for no benefit whatsoever. Often you actually get a downgrade in lifetime, and low ESR capacitors overall had way more problems of simply failing under no load or heat, sometimes when brand new in storage. Top brand low ESR caps of course are very unlikely to fail under no load, however when using something cheap, long life general purpose capacitors are much safer choice for low ripple current applications.

[5U4GB]

Would you consider posting photos of the internals to one of the KA3005D/P threads?  It's been mentioned there but no-one knows much about it or how it compares to the more mainstream KA30xx series.

https://www.eevblog.com/forum/testgear/korad-kkg305dkkg305p/

Interesting, thanks!  Wow, that looks completely different from the previous models, and much better designed, might get one on my next trip to Europe to replace the 3005D.