Global Specialties 1325 80W Compact Power Supply? - Page 1
Forum section: electronics / beginners

author: YurkshireLad
author_rank: Frequent Contributor
timestamp: April 02, 2021, 06:40:06 pm
content: Does anyone know anything about this power supply? I just stumbled across it at the link below, but I don't get any hits when I try to search for information on it.It has a USB port on the front and it looks like it may also have a button for toggling output while the box is turned on. Two things I would like in a bench power supply. It only displays one value on the display, probably the voltage in constant voltage mode, or current in constant current mode. Not the most useful display, but not a big deal.Any thoughts?https://abra-electronics.com/power-supplies-transformers-adapters/ac-dc-adjustable-power-supplies/global-specialties-en/1325-80-w-compact-power-supply-0-16vdc-0-5a.html

author: mvs
author_rank: Frequent Contributor
timestamp: April 03, 2021, 04:15:46 pm
content: I don't think this PSU will make you happy. Specs are really bad, like 100mV Vpp noise.I am sure you will find much better supply for $144.

author: MikeK
author_rank: Super Contributor
timestamp: April 03, 2021, 04:19:49 pm
content: What about the Korad KA3005P, for the same price?

author: YurkshireLad
author_rank: Frequent Contributor
timestamp: April 03, 2021, 07:05:56 pm
content: Thanks. It looks like Digikey has the Korad KA3005P for about C$200, but it doesn't have a USB port, which would be useful. I'll research it though.

author: MikeK
author_rank: Super Contributor
timestamp: April 03, 2021, 08:48:53 pm
content: The KA3005P has USB, the KA3005D doesn't. It *may* be useful. I've rarely used mine. Up to you if you need computer control of the power supply. It's not a power port, by the way, it's a control port. The Global Specialities unit that you were looking at doesn't have PC control, right?

author: YurkshireLad
author_rank: Frequent Contributor
timestamp: April 03, 2021, 08:52:52 pm
content: Ohhhh, I thought it was a power port, to be used to power/charge a USB device. Thanks for clearing that up. I don't need a control port. Scratch that off the requirements list!

author: rstofer
author_rank: Super Contributor
timestamp: April 03, 2021, 10:19:28 pm
content: Here's a review:https://www.eevblog.com/forum/testgear/220v-lab-power-supply-on-110v-mains-korad-ka3005d/

author: YurkshireLad
author_rank: Frequent Contributor
timestamp: April 03, 2021, 10:35:18 pm
content: Thanks. I'd prefer something I don't have to modify; I'm not comfortable messing with anything close to mains. I'm not there yet!

author: YurkshireLad
author_rank: Frequent Contributor
timestamp: April 03, 2021, 11:24:59 pm
content: Any Longwei fans?https://www.amazon.ca/dp/B08BCNWY24/?coliid=I30H7PN04QLSXB

author: MikeK
author_rank: Super Contributor
timestamp: April 04, 2021, 12:43:18 am
content: Quote from: YurkshireLad on April 03, 2021, 10:35:18 pmWhy would you have to modify it? It is a very popular power supply with many owners.

author: YurkshireLad
author_rank: Frequent Contributor
timestamp: April 04, 2021, 01:19:26 am
content: Quote from: MikeK on April 04, 2021, 12:43:18 amThe review says:LOUD FAN - not a huge issue but might need swappingThe transformer is very hot, you will need to mess with the airflowI've watched numerous videos on various Chinese made power supplies saying the supply needs modifications to make them safer or to make their output more stable. I'm a bit.... hesitant?

author: MikeK
author_rank: Super Contributor
timestamp: April 04, 2021, 01:33:03 am
content: No need to be hesitant. Dave did a followup review. That power supply has been through revisions to fix issues...Because of Dave's video review! It's a good power supply. The fan noise is overblown. Weenies! Yeah, it's not whisper quiet...So?I lived for years with the "loud" fan in my Rigol DS1052E. Recently replaced the fan with a quiet one. Yeah, it's a big difference when you compare before and after...But I still lived with it without it bothering me.Heck, I used to live in a shoebox in the middle of the road!

author: YurkshireLad
author_rank: Frequent Contributor
timestamp: April 04, 2021, 01:35:27 am
content: Shoebox? We 'ad to live in't pothole, wi' newspaper for our roof!Is it safe to assume the Korad sold today is the latest revision with all fixes?https://www.amazon.ca/KA3005D-Precision-Variable-Adjustable-Digital-Regulated/dp/B0084JFWNYThanks

author: beanflying
author_rank: Super Contributor
timestamp: April 04, 2021, 02:19:26 am
content: Rather than buying modern cheap junk give some consideration to the venerable 6632Bhttps://www.ebay.com/sch/12576/i.html?_from=R40&_nkw=6632B

author: YurkshireLad
author_rank: Frequent Contributor
timestamp: April 08, 2021, 11:31:38 am
content: One review of the Korad KA3005D on the Amazon link I posted says:"The above scope trace captures an unsafe voltage transient that occurred on the output terminals after the output was disabled, when the power supply power switch was turned off. These transients are 70V peak-to-peak. We tested 4 units in our lab that all do the same thing, (though with inconsistent magnitude) so we are looking for a different model supply that doesn't jeopardize our units that we are testing. When the output is disabled, no voltage applied on the output terminals is acceptable, let alone +/- 35 Volts!"Is this still the case?

author: MikeK
author_rank: Super Contributor
timestamp: April 08, 2021, 12:51:02 pm
content: Quote from: YurkshireLad on April 08, 2021, 11:31:38 amI think that *was* an issue with the first gen board and was fixed. I checked mine after purchasing from Amazon and found no such transients. And when I opened it up I was surprised to find that mine was at least a 3rd or 4th revision board.I would think you'd have a legitimate complaint/return with Amazon if you receive an early unit?Check out Dave's review and followup. There's a vendor on here (tautech, I think?) who posted a followup to Dave's review showing that the issue was fixed. Also there are plenty of reviews/teardowns showing the early complaints and also what early and later units look like inside.

author: mvs
author_rank: Frequent Contributor
timestamp: April 08, 2021, 12:52:32 pm
content: Quote from: YurkshireLad on April 08, 2021, 11:31:38 amThis is not an issue. Switched off output has high impedance and author just picked some noise with his scope probes.

author: MikeK
author_rank: Super Contributor
timestamp: May 02, 2021, 12:01:18 am
content: Well...I hope you pulled the trigger already and are enjoying your hobby.