looking for a new psu - Page 1
Forum section: electronics / testgear

author: electronics man
author_rank: Frequent Contributor
timestamp: March 24, 2014, 05:29:21 pm
content: im looking for a new bench power supply for my lab, i have a budget of about £320, i would love a rigol Dp832 but it is too big for my bench, I have looked at the siglent SPD3033Dhttp://www.siglent.eu/power-supply/spd3303d.html,the GUI looks very nice on this psu, it does look good enough for me and im not looking for anything super presision, all i need to know is is this supply well built and going to last me, if not could someone recormend one for me?

author: PedroDaGr8
author_rank: Super Contributor
timestamp: March 24, 2014, 06:13:25 pm
content: Quote from: electronics man on March 24, 2014, 05:29:21 pmhttps://www.eevblog.com/forum/testgear/siglent-spd3303d-review/It's Siglent, way too new to know if it will last. Some will say its chinese crap so maybe it won't last. Others will say its built well enough maybe it will. The big thing I see is that CH3 has HORRIBLE overshoot problems. This will outright kill anything sensitive you have attached to that line if you aren't careful.Honestly, with PSUs its much better to look for older used PSUs. Thats where the real value is.

author: electronics man
author_rank: Frequent Contributor
timestamp: March 24, 2014, 06:35:39 pm
content: I don't think it seems too bad at all, I think the third channel isn't such a bad thing for me.

author: electronics man
author_rank: Frequent Contributor
timestamp: March 24, 2014, 06:37:27 pm
content: Mabe they have fixed the problem?

author: nanofrog
author_rank: Super Contributor
timestamp: March 24, 2014, 08:25:34 pm
content: Quote from: electronics man on March 24, 2014, 06:37:27 pmWhy the aversion to used?AsPedroDaGr8stated, they offer rock solid performance at pennies on the original MSRP's. Can't beat that value vs. the Chinese supplies available, and although may be nice, digital interfaces aren't critical for a PSU at all.If the DUT is very sensitive to voltage or current, just check it at the DUT with a DMM for an accurate reading, and adjust the supply accordingly (takes voltage drop of the wire between the PSU and DUT into account).Thurlby-Thandar, aka TTi (current listings), would be one that should come up often enough in eBay.co.uk for example.UK members would probably be better at specific brand/model recommendations beyond the TTi listings I linked (i.e. less common/popular than HP/Agilent for example), that wouldn't make your wallet scream for mercy and get you a PSU that would kick the Siglent or Rigol to the curb performance wise. BTW, the older units also tend to be easy to fix should something fail.

author: electronics man
author_rank: Frequent Contributor
timestamp: March 24, 2014, 09:40:17 pm
content: Quote from: nanofrog on March 24, 2014, 08:25:34 pmIf I'm going to spend a lot of money then I want a warranty + there's not much on ebay uk

author: nanofrog
author_rank: Super Contributor
timestamp: March 24, 2014, 10:06:13 pm
content: Quote from: electronics man on March 24, 2014, 09:40:17 pmWarranty is one thing to consider, but do you want to deal with the hassle that can come with warrantying a broken Chinese supply (i.e. replacement unit has the same problem)?Or has it ever crossed your mind that a top quality unit that's been in service for a couple of decades is actually reliable?As per availability, searching for specific models can help, as they may have been misidentified/listed, or even been offered under different brands. I'm just not as familiar regarding what's more common in the UK. TTi was one I could think of that's available on the used market there that you may not have heard of, but built decent gear.Please understand, new does not always mean better or less hassle, and certainly not the best value if you know what you're doing.Just something to think about.

author: electronics man
author_rank: Frequent Contributor
timestamp: March 24, 2014, 10:10:51 pm
content: I think I will just buy the dp832 I can always extend my bench back a little and it is cheaper than the siglent

author: Zbig
author_rank: Frequent Contributor
timestamp: March 24, 2014, 10:39:11 pm
content: Just my 2 cents: I have SPD3303S and wouldn't trade it for DP832. The only known problem with Siglent so far is the power-on spike and overshoot problem on CH3, both of which could just as well already be fixed in newer revisions (discussed in the quoted thread). Rigol, on the other hand has/had problems with overheating regulator and at least two different revisions attempting to fix that, some false small current readings on one channel (with some firmware fixes later on) and the "current flows through the sense wires if you use 'wrong' GND terminal" design fault which, to my knowledge, wasn't and probably won't be fixed at all. Rigol seems to be more "popular" here because it was (sort of positively) reviewed by Dave and, ironically, because it's been talked to death exactly over its multiple issues. Meh, I'd pass. The Siglent's build quality seems very reasonable and anyone who likes to lump SPD together with all random Chinese PSUs, should do the same with Rigol, IMHO.

author: jpb
author_rank: Super Contributor
timestamp: March 24, 2014, 10:50:28 pm
content: I bought my Thurlby Thandar (TTi) supply from test-measure.co.uk but sadly I see from looking at his site that he is now out of stock.The TTi supplies are very good and they do sell ex-demo equipment (I bought my counter from them as an ex-demo).The supply I got, the PL320QMD is very good though it is a little bulky. It only cost me £160 (new but old model bought from test-measure about a year ago).You've not said what your requirements are but as you're in the UK I'd at least look into TTi, power supplies are what they have specialised in for decades.

author: electronics man
author_rank: Frequent Contributor
timestamp: March 25, 2014, 08:04:39 am
content: I realy do need multiple channels, and I'm not sure I like the fine and course adjustment

author: echen1024
author_rank: Super Contributor
timestamp: March 25, 2014, 02:31:29 pm
content: I use old HP/Agilent/Keysight supplies. Good bang for buck, and easy to repair with full schematics and service manual. The E3600 series is quite nice, with excellent specs and simple and easy to repair.

author: nanofrog
author_rank: Super Contributor
timestamp: March 25, 2014, 02:37:56 pm
content: Quote from: electronics man on March 25, 2014, 08:04:39 am10 turn pot adjustment will do nicely. Might be worth looking into as a retrofit project if you can't find one that already has it.

author: electronics man
author_rank: Frequent Contributor
timestamp: March 25, 2014, 04:52:35 pm
content: I could do, I have a few 10turn pots lying around

author: Arkku
author_rank: Contributor
timestamp: March 25, 2014, 05:55:30 pm
content: How about the Owon ODP3032? Anyone have experience with that?

author: electronics man
author_rank: Frequent Contributor
timestamp: March 25, 2014, 08:26:38 pm
content: Quote from: Arkku on March 25, 2014, 05:55:30 pmI would avoid it you can get one from one of the top manufacturers for the same price

author: nanofrog
author_rank: Super Contributor
timestamp: March 25, 2014, 09:16:30 pm
content: Quote from: echen1024 on March 25, 2014, 02:31:29 pmVery well built, top quality supplies for sure.I'm also quite fond of Power Designs for the same reasons.

author: Arkku
author_rank: Contributor
timestamp: March 25, 2014, 11:53:29 pm
content: Quote from: electronics man on March 25, 2014, 08:26:38 pmWell, it's true that it's only slightly cheaper than the DP832, but that's out of stock pretty much everywhere.

author: electronics man
author_rank: Frequent Contributor
timestamp: March 26, 2014, 10:44:31 am
content: Quote from: Arkku on March 25, 2014, 11:53:29 pmI don't think it is cheaper I can get the dp832 for £301 shipped from batronix

author: nctnico
author_rank: Super Contributor
timestamp: March 26, 2014, 12:16:14 pm
content: Quote from: nanofrog on March 24, 2014, 10:06:13 pmEverything has a limited life span. In the last couple of months I bought several HP PSU from the 80's (switchers). One model needed all the electrolytic capacitors replaced, the other model just runs fine after a thourough cleaning.To the OP: Tenma (Farnell sells these) has some small form factor power supplies which (AFAIK) are well within your budget.

author: Arkku
author_rank: Contributor
timestamp: March 26, 2014, 01:59:26 pm
content: Quote from: electronics man on March 26, 2014, 10:44:31 amYou are right, I was thinking of DP832 + HR option.

author: nanofrog
author_rank: Super Contributor
timestamp: March 26, 2014, 02:35:33 pm
content: Quote from: nctnico on March 26, 2014, 12:16:14 pmOf course nothing lasts forever with the parts it was manufactured with.Not to say that top notch performance and reparability isn't possible with new gear, just that it costs an arm and a leg vs. quality used gear (which wasn't cheap when it was originally sold either). In particular, more affordable new gear tends to have compromises that the older gear won't regarding performance, and still tends to be more expensive to boot.So I tend to view used quality gear as offering a lot more value, even if you have to repair/refurbish it (does take some skill in making the right purchase of course, as well as repairing it should that be the case).

author: G0HZU
author_rank: Super Contributor
timestamp: March 26, 2014, 03:03:32 pm
content: The chinese PSUs mentioned on here appear to me to be aimed at the small business user rather than a hobbyist. They offer various programming interfaces and would be suitable for setting up a low cost ATE system.So if you feel you may need to exploit the programming interfaces then these supplies could be a good choice. If not, then I would agree with the other suggestions in that you money would be better spent on 'nearly new' PSUs from TTI/Thurlby.Usually, these won't be programmable although you can get them with GPIB as an option. I have various PSUs from Thurlby here and I'm generally quite pleased with them. At my place of work we nearly always buy bench PSUs from TTI/Thurlby.They are far from perfect and the fine/coarse pots can get noisy/jittery in operation but nothing a quick wiggle won't sort out. But best of all is the very simple layout and the easy to use controls and simple but clear display for voltage and current.I also have some of the early Thurlby PL320 PSUs here from the early 1990s. These have the bright red LED displays. They are my favourite in that they give the clearest display that you can monitor at a glance but they are also the worst built inside. They are not reliable and suffer from intermittent joints and poor layout inside. This leads to dicky display issues and odd effects with the current limiting. Basically these supplies require high maintenance to keep them working reliably.So I'd avoid these ones. The later ones have a softer looking LED display or an LCD display. The build quality of these is much improved but the readability of the display is not as good on the LCD versions.I couldn't live with the Chinese PSUs because the user interface and display are just too annoying for general use. The programmability would be a big bonus (if I needed it) but I couldn't justify £300 for a two rail PSU even if it comes with a warranty.

author: G0HZU
author_rank: Super Contributor
timestamp: March 26, 2014, 04:20:19 pm
content: Here's a couple of images of some of my Thurlby PSUs.The ones below with the bright red LEDs are the (early) ones to avoid because they are poorly built inside. I really like the display on them but they need a lot of TLC to keep them running.The second photo shows the newer type of Thurlby Thandar PSU. These are really well made inside compared to the early ones. I've got a couple of these and they work well. The only downside is the gloomy looking LCD readout. Its not so easy to read at an angle or from distance.The little Philips PSU cost me £15 back in the 1990s and it has been a faithful performer ever since. It only gives 20V 1A on two rails but also does 7V 3A on the third rail. I've got many other bench PSUs but they are all single output type.

author: electronics man
author_rank: Frequent Contributor
timestamp: March 26, 2014, 06:25:50 pm
content: how about this onehttp://uk.farnell.com/aim-tti-instruments/pl303/power-supply-1ch-30v-3a-adjustable/dp/1510521

author: Arkku
author_rank: Contributor
timestamp: March 26, 2014, 07:31:05 pm
content: Quote from: electronics man on March 26, 2014, 06:25:50 pmDoesn't look very attractive with only 1 output, price 2/3 of the DP832, and looks like the adjustments are made using coarse + fine pots.

author: electronics man
author_rank: Frequent Contributor
timestamp: March 26, 2014, 08:13:11 pm
content: Quote from: Arkku on March 26, 2014, 07:31:05 pmno its actually about the same price but every one here seems so attached to tti stuff

author: G0HZU
author_rank: Super Contributor
timestamp: March 26, 2014, 08:51:27 pm
content: TTI stuff is expensive if you buy it new. But you can often buy a used version for a fraction of the priceeg I've seen the (newish) single 15V 4A versions sell for £60 each when sold as used. I paid £95 for each of the Thurlby TS3022S dual PSUs (LCD) I have here and they appear to be as good as new in cosmetic terms.So for about £260 you could expect to be able to buy two used Thurlby Thandar TS3022S PSUs (each with dual 30V 2A rails) plus a TTI 15V 4A PSU. So that's 5 supply rails for the same cost of the single rail TTI supply in Farnell.I got the older PL320 models with the red LEDs for free back in the 1990s as they were faulty and due to be scrapped at my place of work.

author: electronics man
author_rank: Frequent Contributor
timestamp: March 26, 2014, 09:39:02 pm
content: Yeah there are tons of them on ebay