Yihua 10A lab power supply, review and fixing - Page 1
Forum section: electronics / testgear

author: electronupdate
author_rank: Regular Contributor
timestamp: February 23, 2013, 04:20:59 pm
content: I needed a lab power supply which could do at least 10 Amps.... at that current range they become quite expensive.Took a gamble and bought the cheapest supply I could find on eBay, the Yihua PS-3010D. Very much less than awesome, it produces incredible voltage spikes when turning on or off...However, these supplies are so straight forward a bit of time reverse engineering took it from nearly useless to not-bad-for-the-money...If you are considering one, the video attached has some bits of information on what I corrected on mine and a review of the construction and layout of the supply.

author: saturation
author_rank: Super Contributor
timestamp: February 23, 2013, 05:18:02 pm
content: Thanks for your review. I think you need to show it can supply 10A continuously without causing any of the its key parts to fail, such as the power elements, after all that's why you bought a low cost supply rated at 10A. An ideal supply should be able to provide rated power indefinitely. If you did a 24h burn of 30V 10A and it survives then its worth modifying to fix its ripple, calibrate the meters or suppress turn on spikes. If it blows I presume its sufficiently new to be able to return it.

author: mariush
author_rank: Super Contributor
timestamp: February 23, 2013, 05:20:03 pm
content: Wouldn't hacking the front panel to add an on/off switch be easier, when it comes to the overvoltage issue?That way you power on, it peaks to whatever, settles down, and you can then just press the switch the actual jacks.

author: electronupdate
author_rank: Regular Contributor
timestamp: February 25, 2013, 01:30:05 am
content: "Wouldn't hacking the front panel to add an on/off switch be easier, when it comes to the overvoltage issue?"Even with a front panel output enable (a good idea, indeed), I think it would still be good to fix the control loop to prevent the glitch.. otherwise the problem just gets pushed downstream into the next circuit. A simple on-off switch would not work as suspect I would often turn off the main power 1st by accident before the front panel switch...Iperhaps this is why the lab supplies that I use with output-enables seems to be more than just a switch."I think you need to show it can supply 10A continuously without causing any of the its key parts to fail"...I did not include much performance details in the video as I am not sure they would be of interest. I did run this unit for hours-on-end at maximum current when doing some Peltier cooling experiments. It worked fine. I took another look, however, after I read the comment and re-ran the supply at maxium current at @12V.... interestingly, the supply starts out fine at 10A.... but sags down 800 mA as it gets warm. Still works... but the maximum current is not reached (it did run, however, for hours @ 9.2A).All-in-all it was still an ok buy @ $140.... a supply from a better tier vendor like B&K was $400 and the Agilent units ran into 4 figures!

author: AlphZeta
author_rank: Regular Contributor
timestamp: February 25, 2013, 05:35:30 pm
content: Hmm. The heatsink for the power transistors looks inadequate, even with the forced air cooling. I am wondering what the temperature is like when it's under the worst case scenario.

author: saturation
author_rank: Super Contributor
timestamp: February 25, 2013, 06:38:06 pm
content: Other reviews has been done in the past, maybe Yihua has improved since then but the faults discussed in another thread raised serious concerns:https://www.eevblog.com/forum/reviews/beware-yihua-yh-305d-bench-psu/msg99235/#msg99235For the same money, other China makes are a safer bet e.g. Mastech and discussed in the archives.

author: Spawn
author_rank: Frequent Contributor
timestamp: February 25, 2013, 06:46:09 pm
content: Thanks for the review electronupdateI got one of these almost a year now, I only use it to test automotive lamps and for “not so fine” electrics stuff. I also changed the connectors because it came with burned plus banana plug insert out of the box, so I put some 30A connectors in there.Saturation, you mention to put it on a test with one day at 30V and loading 10A, I wouldn’t even dare to test that for 10 minutes unattended, I am afraid it will catch fireHence the burned banana plug inserts out of the box, probably that happened while it was being “tested” at the factory. I am sure electronupdate's unit did survive the test like he said, but I am not sure if mine will.I did post some pictures of mine before here:https://www.eevblog.com/forum/reviews/beware-yihua-yh-305d-bench-psu/msg99235/#msg99235I wouldn’t recommend this power supply for a electronics hobbyist, for me it is only on my bench for testing not so delicate stuff not more than for couple minutes.

author: saturation
author_rank: Super Contributor
timestamp: February 25, 2013, 07:28:15 pm
content: Yes, I presume a tester would monitor it during the test so a catastrophe won't happen and the test aborted to avoid a mess. The OP mentions he ran it for 'hours' at 9A which is 90% of its rated current, so its not too shabby. The Amazon link suggests some improvement in recent purchases so maybe there is a better batch.Quote from: Spawn on February 25, 2013, 06:46:09 pm

author: Spawn
author_rank: Frequent Contributor
timestamp: February 26, 2013, 03:13:40 am
content: Quote from: saturation on February 25, 2013, 07:28:15 pmThey improved it maybe then, I was not happy with wiring and the big capacitor dangling around in the case when I opened it first time.

author: smackaay
author_rank: Regular Contributor
timestamp: February 27, 2013, 04:36:36 am
content: I have one as well, wrote a little review of it herehttp://smackaay.com/2013/01/22/the-yihua-ps-3010d-dc-power-supply-quick-review/Just a couple things about this thing is the fact that it's as loud as a vacuum cleaner and when I was testing it at 10 amps, the LED display went screwy.

author: saturation
author_rank: Super Contributor
timestamp: February 27, 2013, 08:23:05 pm
content: Thanks for the links! Even if it couldn't provide 10A, but 9A or so, it would be fine, but what voltage can you get when pulling higher amps? Again, this is a need for more testing. There are other Chinese brand PSU that will do closer to what you pay for, I think we need to see that from this model, or consider a used name brand such as Kenwood, Kikusui etc., from eBay that often go for under $100, delivered.But thanks again to the OP for making the test, which spurs others to think more about this model.Quote from: smackaay on February 27, 2013, 04:36:36 am

author: Spawn
author_rank: Frequent Contributor
timestamp: March 22, 2013, 12:33:58 am
content: Saturation, I tested mine too at highest voltage and current while I was testing my new (old) PSU analyzer after fixing it, the Yihua stopped delivering current after 5 minutes and after another 2 minutes after cooldown it worked again, so my unit is not holding long but display didn't do anything wrong.See here

author: saturation
author_rank: Super Contributor
timestamp: March 22, 2013, 04:45:45 pm
content: Thanks Spawn, it sounds like it tripped protective circuitry or its overheating; it saves your device, but it can't deliver what you paid for; I presume if you pay for 300W you should get 300W but if its fairly close it could still be good value. Try playing with reduced output current or voltage until the device will reliably work and not shut down, I would say a minimum of 8 hours [a whole working day period] and that will be the new rated output power, V x I. If it has an on-demand fan for cooling that can't keep up, you could mod it to provide higher flow; an easy way to test this is remove the cover and let the unit breath more, or point a fan to the open chassis to blow on it; if it doesn't shut down it thereafter then better cooling will indeed help.Quote from: Spawn on March 22, 2013, 12:33:58 am

author: amyk
author_rank: Super Contributor
timestamp: March 22, 2013, 07:19:43 pm
content: Quote from: saturation on March 22, 2013, 04:45:45 pmDo the specifications say anything about peak vs continuous ratings or a duty cycle? The Chinese love using peak power ratings because they look better...

author: Spawn
author_rank: Frequent Contributor
timestamp: March 23, 2013, 12:45:06 am
content: Saturation, when I am at home 8 hours and can monitor it, I can give it a go at 9A. These are busy weeks at work so I can promise anythingAmyk, I am not sure but if I remember correct it was not peak output, I can’t find the manual which came with.

author: skipjackrc4
author_rank: Regular Contributor
timestamp: March 24, 2013, 01:37:02 am
content: If you are needing 10A, perhaps an old Sorensen would be better? They can be had on eBay for <$200 if you watch for a while, and were a subsidiary of Raytheon, so they're well made. They're a bit larger that your Chinese supply, though, at 3-4 rack units tall rack units tall. We have tons of them at work and they run forever. I plan on picking up a 40V 13A one soon.

author: 84750Erik
author_rank: Contributor
timestamp: November 28, 2018, 08:38:34 pm
content: A power supply exactly like this one gives awfull ripple: 2Vpp, no load. Under load it is a bit less. At any voltage. Any idea where I would have to start looking?

author: coromonadalix
author_rank: Super Contributor
timestamp: November 29, 2018, 02:58:32 am
content: find an good old linear model, less hassle and worry, and less ripple at the output, 2v pp is very awfulmy 2 cents

author: nctnico
author_rank: Super Contributor
timestamp: November 29, 2018, 08:35:50 am
content: The ripple probably isn't there at all but induced in the ground loop of the probe. Connect a BNC cable directly between the PSU and the oscilloscope. Still switching power supplies are noisier than linear ones. Adding a common mode choke and capacitors across the input and outputs may help.

author: Calambres
author_rank: Frequent Contributor
timestamp: November 29, 2018, 09:46:20 am
content: I have a Lavolta BPS305, a very similar PS only 5A max. It also suffers from such spikes but I have only observed this when doing a cold startup, that is, when I start the PS from a long period of inactivity. If I switch it on or off once it has been working for some minutes, the spikes almost disappear. What it is fun and even a contradiction with what I have just said is that the ON spike is of a much lesser magnitude that that of turning the PS off, which can triple the nominal voltage!Shortly after I got this PS I modded it to add a momentary toggle switch that short circuits the outputs in order to make the current adjustment easy:I have found that if I turn this toggle on while starting up or turning down the PS the spikes disappear completely!

author: Markino
author_rank: Contributor
timestamp: November 29, 2018, 03:49:15 pm
content: Hi guys,I also have the Lavolta ones!I'm a beginner and I never check for the spikes but I'd like to do it!Can my new Brymen BM257s Multimeter help me to check the spikes or I need some other instruments?I also have a JYE DSO Shell....PS: what do you think of this Italian (hope google translate can help you) review and suggestion to improve our PS?http://www.audiovalvole.it/alimentatore_laboratorio_ps-305d.html

author: Calambres
author_rank: Frequent Contributor
timestamp: November 29, 2018, 05:18:18 pm
content: Quote from: Markino on November 29, 2018, 03:49:15 pmInteresting!... thank you.