Bench power supply suggestions [intermediate level, undergraduate EE] - Page 1
Forum section: electronics / testgear

author: belzrebuth
author_rank: Frequent Contributor
timestamp: September 21, 2019, 08:36:02 am
content: Hi,I'm looking at purchasing a power supply to replace my current one which is a Farnell LT-30/2.I get by with the one I have but my main concern is the digital readout which I don't have and I have to check the actual output voltage with a multimeter every time. Im not doing anything critical but digital readout would be a nice thing to have.Also 3 channels would be great (additional 0-5V to the main +- outputs as the need to power something that requires 12v/-12V and 5V is frequent.Low ripple and noise are also required for many of my projects which mainly consist of audio circuits.I'm currently looking at the rigol dp832 as I already have a dg1022z and a ds1054z but any other alternatives would be welcome.!(My budget's upper bound is around the price of the 832.)

author: AVGresponding
author_rank: Super Contributor
timestamp: September 21, 2019, 09:01:09 am
content: My personal preference would be to go for a pre-owned HP or something similar, I'm not a big fan of any of the Chinese brands for serious work.I expect they'll get there eventually, quality wise, but they are a long way off yet imo

author: belzrebuth
author_rank: Frequent Contributor
timestamp: September 21, 2019, 09:44:52 am
content: I was looking at the 6236B in order to get triple output but again no digital display..E3630 would be another option for old HP but it is more difficult to find in good condition and ends up almost as expensive as the dp832 (which can provide a lot more current) including shipping and taxes to EU.

author: AVGresponding
author_rank: Super Contributor
timestamp: September 21, 2019, 10:10:44 am
content: Well, if the only bad thing about your existing psu is the lack of digital metering, how about one of these?https://www.ebay.co.uk/itm/Thandar-TTI-TS3023S-linear-bench-power-supply-PSU-0-30V-0-2A-triple-output/254336895974?hash=item3b37a90be6:g:VzQAAOSw5R5dXXO0Or buy yourself a nice toroidal tranny and build your own

author: belzrebuth
author_rank: Frequent Contributor
timestamp: September 21, 2019, 10:36:23 am
content: Too bulky but thanks for the suggestion!Building my own is not an option as I want it to be safe and reliable and it's probably going to look ugly if it's diy.What's wrong with the DP832?It's Chinese alright but Rigol seems like a solid company from what I read around.I also have no problems with what I've bought so far.

author: tautech
author_rank: Super Contributor
timestamp: September 21, 2019, 10:42:42 am
content: Recent thread:https://www.eevblog.com/forum/beginners/beginner-bench-power-supply-question-before-buying/There is an issue with DP832 in that 2 outputs share a ground you need be aware of.Others have been put off them because of this.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: September 21, 2019, 11:08:28 am
content: So the problem lies if I want to have say +-12 and -5V ??Meaning I can only have two truly independent voltages (ch1&2) or three independent voltages (making the appropriate connections) but keeping in mind that ch3 could only be +-5V?If setting both ch1 and 2 to 10V and connecting say the ch1(+) to ch2&3(-) couldn't I get +-10v and -5V?What's a practical use that's hindered by the dp832's limitation?

author: AVGresponding
author_rank: Super Contributor
timestamp: September 21, 2019, 11:13:56 am
content: The thing that puts me off is the inconsistent build quality; hand soldering in particular seems to be a skill in short supply.Obviously everything is built to a price (lowest, best quality, best compromise etc.), I just think the Chinese gear is still on the wrong side of "best compromise" at the moment.

author: GerryR
author_rank: Frequent Contributor
timestamp: September 21, 2019, 11:29:59 am
content: Try an older Tektronix PS280: 2__0-30 V @ 2 A ea. CC-CV; 1__5 V @ 3 A. I don't know if you can still find them, but I have had mine for years, and it has been very reliable.

author: nctnico
author_rank: Super Contributor
timestamp: September 21, 2019, 11:46:25 am
content: I'd recommend against getting an older power supply. These usually have very low resolution readouts so you always need to check the voltage with a DMM. Which is what you want to avoid. Besides the Rigol and Siglent PSUs already mentioned the GW Instek GPE-2323 is also worth considering as a lower cost alernative. If money is less of a concern then the Keysight E3631x series is very nice. Call me weird but I'd either buy the GPE-2323 or a Keysight E3631x series. The first has no advanced features and the latter has all the pros from the Rigol and Siglent supplies combined.But do read the thread Tautech pointed to.

author: 2N3055
author_rank: Super Contributor
timestamp: September 21, 2019, 11:50:04 am
content: AIM-TTi makes good PSU-s.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: September 21, 2019, 02:57:01 pm
content: Anyone have the DP832?Any complaints?!I think this is my best option if buying new with my current budget..

author: themadhippy
author_rank: Super Contributor
timestamp: September 21, 2019, 03:44:26 pm
content: QuoteBuy a couple of digital voltmeters that can be found all over ebay for pennies,and build a simple 5v psu.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: September 21, 2019, 04:00:10 pm
content: I thought of that too, but the 5V would require a separate 9V transformer and extra circuitry which I should mount inside the case which is already tight.I could hack 5V in there if I wanted to but no CC.I like the instrument as it is so I don't want to replace the meters with eBay displays etc.An extra pair of terminals for the 5V should not spoil it for me but I don't like modding stuff in general if it's showing on the outside..I've already replaced the pots with multiturn bourns and it made a world of difference but I don't think I want to put displays in there especially the noisy stuff you can find on eBay.I'm going to keep using this power supply as it is just wanted a newer tool that would make it easier for me to dial in some voltages with more precision.I don't like this power up thing..1V is not that low..I think I'm going to have to keep looking.E3631A is nice..seems like very well built.

author: Frex
author_rank: Regular Contributor
timestamp: September 21, 2019, 04:35:26 pm
content: Hello,I own some month ago a ITECH IT6302 power supply from Aliexpress (about 300€ with shipping).It's a very good unit, very pleasant to work with.Build quality is very good.Note that the same unit is rebranded to Keithley 2231A-30-3 and B&K Precision 9130.Regards.Frex

author: belzrebuth
author_rank: Frequent Contributor
timestamp: September 21, 2019, 04:44:27 pm
content: Quote from: Frex on September 21, 2019, 04:35:26 pmThis is very interesting.Really good looking unit..I'm sure customs will appreciate it too when it gets hereBut really, this is a very nice power supply.I'm going to have to take a closer look.

author: Vaiti
author_rank: Contributor
timestamp: September 21, 2019, 05:12:05 pm
content: You can grab the ITECH IT6302 from Batronix, should save some customs hassle.

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: September 21, 2019, 05:16:20 pm
content: Quote from: belzrebuth on September 21, 2019, 02:57:01 pmI have the DP832 but it thinks it's a DP832AIt's a REALLY nice power supply, don't know about the power up glitch thing. I changed the fan cos it annoyed me (I have a full thread on that somewhere here).

author: Vaiti
author_rank: Contributor
timestamp: September 21, 2019, 05:30:43 pm
content: The two downsides to the DP832 are the unregulated power spike on bootup and Channel 2 & 3 sharing a ground. Other than that it is a very nice supply. Fan noise might also be a downside, but that is correctable and not all that noisey. It is easily hackable into a DP832A.

author: maginnovision
author_rank: Super Contributor
timestamp: September 21, 2019, 06:20:59 pm
content: I have the 832 and like it, the competing siglent is also nice but I would rather have a keypad for entry and fully adjustable(and monitored) channel 3 as opposed to 3 isolated channels but 1 just being a selectable voltage supply. It's like a very nice wall wart, all you know is the output voltage. I don't do much work with differential voltages though, and when I have I've used another supply. The siglent is much shallower than the Rigol too which can be a big issue depending on your workspace. The TTi supplies look good too but I haven't personally used one to compare performance.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: September 21, 2019, 10:15:36 pm
content: Great! Now I'm torn between the dp832 and the ITECH IT6302..Any issues with the ITECH IT6302 that I need to be aware of?

author: tautech
author_rank: Super Contributor
timestamp: September 21, 2019, 10:20:23 pm
content: Quote from: belzrebuth on September 21, 2019, 10:15:36 pmDoes it give enough displayed info for your needs is the first question I would ask myself ?

author: belzrebuth
author_rank: Frequent Contributor
timestamp: September 21, 2019, 10:30:59 pm
content: I like the extra features of the Rigol but I wouldn't really mind just voltage and current display if the power supply is trustworthy and clean..Maybe less clutter is not a bad thing..If it's really good I don't see any reason not going with the ITECH even if I never heard this brand before.. Although having a LAN option would be great.I'm going to have to look closer to the DP832A options that are "unlockable" on the the DP832..Maybe I could use some the advanced features and with these enabled maybe the Rigol unit would be more cost effective in the long run..

author: tautech
author_rank: Super Contributor
timestamp: September 21, 2019, 10:37:04 pm
content: ITECH have been around for years.SPD3303X-E with its big bright display doesn't interest you ?Yes and it's unlockable to the X model too !

author: belzrebuth
author_rank: Frequent Contributor
timestamp: September 21, 2019, 10:46:09 pm
content: I'm not around for years so maybe that's that.I haven't looked at the siglent options yet..Maybe I have to..I'll watch a video or something of the SPD3303X-E..There must be a lot of info available for it.The most prominent reason price aside that I looked at the Rigol was that I also have two other Rigol units and the three of them would communicate easier (since it's unlockable even more so).

author: tautech
author_rank: Super Contributor
timestamp: September 21, 2019, 10:49:29 pm
content: Quote from: belzrebuth on September 21, 2019, 10:46:09 pmUnderstood.However communication between the Rigol stuff you already have and a PSU is a very unlikely use case.Care to share one ?

author: belzrebuth
author_rank: Frequent Contributor
timestamp: September 21, 2019, 10:51:48 pm
content: On top of my head: just less software on my computer..No particular scenario comes to mind except that I'll have only one manufacturer to blame if something goes wrong.

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: September 22, 2019, 01:58:08 pm
content: I own both the SPD3303X-E and the DP832 (that thinks it's a DP832A); here's a quick comparison.The 2 major gripes on the Rigol are that the fan is noisy (was, I replaced it) and the ground for Ch3 is shared with Ch2 but that hasn't stopped me from configuring it for any use I have needed so far. The DP832A color display is clear and, although it looks like a pie chart, I have really warmed up to that display mode.The Siglent's Ch3 can only be set to one of 3 voltages (2.5, 3.3, and 5) and the only current limiting Ch3 has is a fixed 3.2A which makes Ch3 almost unusable IMHO. The display is bright and big but, when the white on cyan select effect is applied to a parameter, I find it difficult to read and I end up crouching down to get closer to see the value I'm setting.The Siglent has poorly-designed and sloppy binding posts (even after they sent me new ones to fit myself) and some cheaper banana plugs are almost unusable with it - you only have to touch them and they drop out; these same banana plugs work perfectly on the Rigol.Rigol claims Low Ripple Noise <350 uVrms/2mVpp and fast transient response time: <50 us. Siglent specs say Ripple&Noise ≤1mVrms（5Hz ～ 1MHz）with the same response time.Overall, I much prefer the DP832(A) but it is bigger and heavier if that's an issue for you.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: September 22, 2019, 02:08:04 pm
content: I think I'm set for the DP832. It has probably a lot more than I could ask for and the price is just about what I can give for a psu at this point.Getting it to DP832A specs makes it even more desirable.Thanks for your insight Gandalf_Sr.Would you mind sharing the fan model you've used?I also plan to replace the fan on my DS1054z as well.I find myself using my old Tek 2235 more frequently because of the fan noise..

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: September 22, 2019, 02:23:47 pm
content: You're welcomeHere'sthe linkto the fan replacement.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: September 22, 2019, 02:26:33 pm
content: Thanks:)One last thing!Has that overshoot issue ever caused any problems to you?!I was worried a bit for digital logic stuff but I don't think I ever used something with a logic threshold of sub 1 volt..

author: maginnovision
author_rank: Super Contributor
timestamp: September 22, 2019, 05:02:29 pm
content: Typically it's not an issue since the circuit won't be actively powered at startup. That issue is only when switching it on with the mains power switch.

author: belzrebuth
author_rank: Frequent Contributor
timestamp: September 22, 2019, 05:12:08 pm
content: Oh, I thought it was an output enable thing..Great news!

author: Vaiti
author_rank: Contributor
timestamp: September 22, 2019, 05:49:40 pm
content: Quote from: Gandalf_Sr on September 22, 2019, 01:58:08 pmYou can get a normal colored non pie chart display out as well, in case you didn't know. Just have to get into settings and change the display mode.

author: TurboTom
author_rank: Super Contributor
timestamp: September 22, 2019, 05:55:32 pm
content: This threadcovers the mains power-up glitch pretty well. General consensus is that at least in case of the DP832 (A), it's nothing to worry about.

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: September 23, 2019, 08:52:17 am
content: Quote from: Vaiti on September 22, 2019, 05:49:40 pmI did know that you could get that colored display but thanks for pointing it out. After you convince the DP832 that it's a DP832A, the default display mode is 'pie chart' (I think) but you can get any of the other displays too. What you don't get after the conversion is the colored LEDs behind the    buttons, I haven't got round to fitting the 0805 LEDs to mine yet.I haven't experienced any start up glitches and I do leave stuff connected to Ch1 while I power up the DP832(A)

author: Leiothrix
author_rank: Regular Contributor
timestamp: September 23, 2019, 09:51:20 pm
content: I bought one about a year ago. I was tossing up between a used HP, a Rigol DP832 and a Siglent SPD3303X-E.HP got scratched because I'm in Australia, so finding something decent at a non-stupid price is kinda difficult sometimes.Rigol got scratched because its case is enormous and wouldn't fit on my desk.So I got the Siglent. No complaints from me, it does everything that I want it to.Just check the physical dimensions before you commit to anything.

author: rstofer
author_rank: Super Contributor
timestamp: September 23, 2019, 11:19:33 pm
content: Quote from: belzrebuth on September 21, 2019, 10:36:23 amI have that PS and it works just fine. In at least one way it is more user friendly than the Siglent equivalent in that there is a keypad for numeric entry instead of just spinning a knob. It has a knob for minor twiddling.I also have the DS1054Z scope and it also works very well.When you look at PSUs with current limiting, read the manual to see how it is adjusted. The Rigol, and most higher quality PSUs, will have a digital adjustment that is set with the voltage off. The cheap supplies expect you to short the output and turn a pot. Not my favorite way of setting things.There has always been Chinese bashing on this forum. Some warranted, some not. And, yes, an HP supply would be nice as long as it had equivalent features for a lower price. It won't... There are lots of supplies with analog meters and they're cheap enough, I suppose, but they aren't what a modern PSU should be. That's why they're sold as surplus.Here's Dave's review of the DP832ETA: So, I watched the video only to discover that I use about 1% of what the PS can do.

author: Mr. Scram
author_rank: Super Contributor
timestamp: September 24, 2019, 12:01:42 am
content: Note that tautech is a Siglent dealer notorious for trying to push the brand in every thread. The Rigol is a popular option and serves a lot of people well including the not-so notorious Dave Jones.

author: tautech
author_rank: Super Contributor
timestamp: September 24, 2019, 12:10:34 am
content: Quote from: Mr. Scram on September 24, 2019, 12:01:42 amSo you might think !Really not everyone is aware that Siglent offer a good PSU so I make them aware a Siglent PSU might be a viable option.I don't get what you see is wrong with that.After all it's up to theinformedbuyers choice how they spend their dosh, not yours, mine or anyone else !

author: rstofer
author_rank: Super Contributor
timestamp: September 24, 2019, 12:11:09 am
content: Quote from: tautech on September 21, 2019, 10:42:42 amIt simply means the if you want +-15V and 5V, channel 2 MUST be the +15V supply, The (-) side of Channel 2 is commoned with the (-) side of channel 3. Not a big deal at all. In my world...

author: maginnovision
author_rank: Super Contributor
timestamp: September 24, 2019, 12:16:08 am
content: Quote from: rstofer on September 24, 2019, 12:11:09 amI've always found that so awkward to setup(in my head) I just use a second supply. It does work though.Quote from: tautech on September 24, 2019, 12:10:34 amWhen I respond to these threads I typically recommend the siglent as well. The two units have some minor differences which can throw one or the other out just on preferences. Then there is the size difference. They are both lower cost units that will do the job though and I don't think people can go wrong either way now that they've both got their bigger issues solved.

author: rstofer
author_rank: Super Contributor
timestamp: September 24, 2019, 12:19:23 am
content: Quote from: tautech on September 24, 2019, 12:10:34 amThe business relationship is right there on the signature line so it is certainly not being concealed in any way. It is actually useful to get informed comments re Siglent and it's too bad there isn't a Rigol distributor contributing as well.

author: rstofer
author_rank: Super Contributor
timestamp: September 24, 2019, 12:30:23 am
content: Re: the DP832 videoDave didn't talk about the difference between the voltage & current settings and the voltage & current limits. The power supply will try to control the output to stay within the voltage & current settings. If either the voltage or current somehow exceeds to 'limit' value, the output will shut down.This PS is very useful for bringing up new projects. I did a Z80 project a while back and I had an address conflict. I had set the current quite low and when the device current reached the setpoint, the voltage dropped to near zero. I could tell immediately that there was a problem and I didn't have to worry about the magic smoke pouring out of the chips.A very nice supply. It's the one I have but I am sure there are many others that work the same way.

author: JxR
author_rank: Unknown
timestamp: September 24, 2019, 12:34:42 am
content: If I was in the market for a 3ch supply, I would seriously consider the GW Instek GPP-3323. About the same price as a DP832, but can be used as an Electronic Load in CV,CC, and CR modes.Power Supply:Ch1/2: 0-32V 3ACh3: 5V/3.3V/2.5V/1.8V @ 5AElectronic Load:Ch2: 0-32V 0-3A (50W max)The only thing I personally don't care for is a lack of sense terminals on any of the models above the single channel version. Although I don't believe the Rigol or Siglent being discussed have sense terminals either.I attached the datasheet.

author: Mr. Scram
author_rank: Super Contributor
timestamp: September 24, 2019, 12:38:24 am
content: Quote from: tautech on September 24, 2019, 12:10:34 amYou do push the brand in pretty much every advice thread you participate in and are well known for it amongst regulars so no discussion there. I agree that people should make informed decisions which is why they need to be aware of the interests of those supplying suggestions.

author: rstofer
author_rank: Super Contributor
timestamp: September 24, 2019, 12:41:30 am
content: Quote from: Gandalf_Sr on September 22, 2019, 01:58:08 pmThe old color monitors (think Sony MultiSync CRT type) and linear power supplies share one thing in common: You buy quality by the pound. A heavier supply is better than a lighter supply. For the PS, you're buying a more robust transformer and more heatsinking. The weigh difference isn't in the PCBs themselves, it's in the metal stuff. More weight is good!Unless the difference is insignificant. But if it is multiple pounds, buy on weight.

author: Mr. Scram
author_rank: Super Contributor
timestamp: September 24, 2019, 12:44:21 am
content: Quote from: rstofer on September 24, 2019, 12:19:23 amThe signature line isn't always visible depending on the device you use to view the forums. It's easy for people to overlook the line regardless and several in the past did so there's no harm in making sure everyone knows what's what.

author: tautech
author_rank: Super Contributor
timestamp: September 24, 2019, 01:05:35 am
content: Quote from: Mr. Scram on September 24, 2019, 12:44:21 amWhich is exactly the reason why I shifted my disclosure to my profile andnotsignature.It's plainly visible for all to see.It would seem you get disturbed when someone buys a Siglent product after assessing datasheets from all other competing brands. Are you some <brand> closet fanboy ?

author: Mr. Scram
author_rank: Super Contributor
timestamp: September 24, 2019, 01:29:26 am
content: Quote from: tautech on September 24, 2019, 01:05:35 amWhy do you get upset about making sure people get all the relevant information? According to your own words we both are in favour of informed decisions so there's no need for the salty attitude. I have no issue with Siglent other than you pushing the brand so aggressively and one-sidedly that a lot of noise is introduced. This tends to happen in threads started by newcomers who ask advise and are most susceptible to it. There are many brand representatives who makes themselves useful around here who I don't have any issues with. Coincidentally they're a lot less zealous and better at providing information in a neutral manner.

author: nctnico
author_rank: Super Contributor
timestamp: September 24, 2019, 08:13:15 am
content: Quote from: rstofer on September 24, 2019, 12:41:30 amNo. Think about (efficient) torroidal transformer versus an old style one. Also more weight can mean cheaper steel enclosure instead of aluminium. Either way heavy equipment is a nuisance to move around.

author: GerryR
author_rank: Frequent Contributor
timestamp: September 24, 2019, 11:28:53 am
content: The older "stuff" is straight-forward and easier to use. I would gather that most of the features of these newer supplies, very few people will use, but the displays look pretty. I don't care what the supply "says" the output is, or to how many digits, I always check the outputs with a calibrated multi-meter before hooking up to a circuit; it's just good practice. I think there is a tendency for some to go for appearance as much as anything else. Features like "sense" inputs on a bench supply(??), maybe if your test setup is across the room, but not on a bench. Just measure the voltage at the destination and tweak the supply, if necessary. CC / CV definitely a must and independent grounds, very convenient. Weight is good, if for nothing else but to keep the unit from moving when you go to change a control setting. (I have a newer ARB that slides away from my hand when I go to depress a button; most annoying. My older, less capable ARB would'nt do that. There is a lot to be said for the industrially hardened equipment instead of what is being passed off today. Just my $.02.

author: nctnico
author_rank: Super Contributor
timestamp: September 24, 2019, 01:05:47 pm
content: Quote from: GerryR on September 24, 2019, 11:28:53 amNot in today's world. For older PSUs with 2.5 digit readouts for voltage and current or a scale you'd need to check the output voltages. But nowadays the higher end bench power supplies come with 4.5 digits DMMs built-in for both current and voltage. Especially the current is a good one because unlike a DMM a power supply doesn't have any extra burden voltage. Also you may want to change the voltage in between or use the PSU the next day again. Do you really want to pull out a DMM and check every output voltage and current of a power supply? It is a real nuisance to have to work that way.

author: 2N3055
author_rank: Super Contributor
timestamp: September 24, 2019, 01:15:11 pm
content: Quote from: nctnico on September 24, 2019, 01:05:47 pmTo be more precise, if you have something like DP831/832 you get 3 x voltage and current and power. That is 9 measurements that are just there with no effort.I use my DP831 ALL the time just because of that.. And resolution is enough that you don't need anything else most of the time.And Keysight 36300 and 36100 series have low range current mode that is good enough to measure low power devices with full range scale range of several mA...