Be Wary of the X-Tronic 6080 DC Power Supply - Page 1
Forum section: electronics / general

author: deanriverson
author_rank: Newbie
timestamp: July 23, 2013, 06:35:49 pm
content: I bought one of these 0 - 30V DC power supplies on eBay. The first time I powered it up, everything seemed fine so the next time I needed a power supply for a project I used it. Big mistake! After a few minutes the output jumped to 50V and damaged the part it was powering. It may be a problem with just the one I bought, but I wanted to at least put out a warning. Maybe it will save someone else from damaging their project.Video showing the power supply outputting 50V is here:Dean

author: amyk
author_rank: Super Contributor
timestamp: July 24, 2013, 10:38:29 am
content: We've seen this before.

author: saturation
author_rank: Super Contributor
timestamp: July 24, 2013, 11:27:20 am
content: Its important to thoroughly test you PSU before adding it to your lab. The single toughest test is to draw maximum output power for a day say to a power resistor, if it fails you can return it as damaged. Monitor it for overheating. For those nameless China PSU that would be difficult to return, reduce test output power to half and never use it above half. After the torture test, test the usuals: turn on waveform, regulation etc.,FWIW I did the same to my Mastech linear PSU to maximum output power and it passed. I use it still today. I paid $90 delivered in 2010.http://www.mastechpowersupply.com/dc-power-supply/linear-power-supply/volteq-regulated-variable-dc-power-supply-gps-3030d-30v-3a/prod_62.html

author: deanriverson
author_rank: Newbie
timestamp: July 24, 2013, 09:28:12 pm
content: Great advice, saturation! I will definitely do this from now on.

author: diode702
author_rank: Newbie
timestamp: July 24, 2013, 10:43:43 pm
content: You must have gotten a defective power supply. I bought 2 of x-tronix 0 to 30 volt o to 5amp supplies about 5 months ago and they are both doing fine, One of them is on 24 hours a day with a 4 amp load and it still working great but it does get a little warm though. I bought mine from the MERCANTILE STATION an veryhappy with them. Just send it back and they will give you another.73's Dennis W5VAF RETIRED BROADCAST ENGINEER.

author: deanriverson
author_rank: Newbie
timestamp: July 24, 2013, 11:04:33 pm
content: Glad you had better luck than I did. On the bright side, Mercantile Station did a great job on the customer service front. They offered to send me a new one right away but I opted for a refund. They promptly refunded my money with no hassles.

author: Spunky
author_rank: Regular Contributor
timestamp: July 26, 2013, 04:01:05 am
content: I think these are all made by mastech, often sold unbranded. I have one that kicked out 28v AC when it was set on 20v DC. When earth referenced it burned out it's earth wire.There's a heatsink inside with some mosfets or similar on it grounded to the case, turned out the assembler had screwed them on so tight he'd cut through one of the insulators and grounded the output to the chassis. An easy no-cost repair (easier than returning it) and now it's working fine. I have no idea what it's life expectancy is but it seems to be doing a good job right now.One thing I'd say is that the wires were a little messy inside and the wiring to the banana jacks is a little dodgy. They also seem to have added a capacitor straight across the jack plugs (an afterthought?), which needed bending a little further away from the earth plug to make me feel comfortable.I think the product is essentially ok but they really need to get a grip on their QA, they're sending these things out without even switching them on.

author: saturation
author_rank: Super Contributor
timestamp: July 26, 2013, 12:25:12 pm
content: There are many tests for a PSU, overall its under standard IEEE 1515, which include some tests mojo-chan mentioned.http://standards.ieee.org/findstds/standard/1515-2000.htmlHowever, the simplest test is one of reliability, which is to do a burn-in, officially you'd want to calculate an MTTF for the device, which can be done with varying times, loads and ambient temps.But the essence of a burn in is to run for its rated specification for the maximum time expected to be used, and is the single best test; it is not for quality of output or robustness, but one of longevity.http://www.digikey.com/Web%20Export/Supplier%20Content/MurataPower_811/PDF/Murata_CD-Burn-In.pdf?redirected=1Murata's test is common in the industry, and they run it for typically 48 hours.I don't think Mastech makes all these PSU, you can see that in a tear down of various similar looking models in the eevblog forum archives. They clearly copy each other but quality and workmanship of many non-Mastech models vary substantially, while those branded Mastech tend to look better; its not all of them, but more by model number. If you check Amazon.com for those sold there, you'll find reviews are generally good [ 4 stars and up].