EEVblog #828 - Siglent SPD3303X precision Lab PSU Teardown - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: December 09, 2015, 09:20:09 am
content: Inside the Siglent SPD3303X Precision Programmable DC Lab Power Supply.http://amzn.to/1m9Knp2UPDATE: There is an even cheaper version, the SPD3303X-E which has 10mV/10mA resolution.http://amzn.to/1jNsQRL

author: brutester
author_rank: Contributor
timestamp: December 09, 2015, 09:54:17 am
content: At around 13:20 I would say that those diodes are for system supply for CPU, DAC, etc, not 3rd output

author: EEVblog
author_rank: Unknown
timestamp: December 09, 2015, 09:56:00 am
content: Quote from: brutester on December 09, 2015, 09:54:17 amNope, keep watching, the CPU etc has it's own bridge and big filter caps on the front panel board. The bridge gets damn hot too.

author: Opticalworm
author_rank: Contributor
timestamp: December 09, 2015, 10:41:17 am
content: Good news Dave, linux is probably not an option for this supply. The STM32F207VE is a cortext M3 with around 512KB of memory.My money is on an RTOS.-Ron

author: rs20
author_rank: Super Contributor
timestamp: December 09, 2015, 10:44:50 am
content: 26:30-- If you have the output physically shorted, the voltage you choose is irrelevant. It's in constant current mode. So there's no point in settings it to 1V or whatever to make it maximally stressful, you've already achieved that with the shorted outputs.29:30-- Is this oscillation caused by the dummy load, or by the PSU (or by the combined feedback loop)? Put another way, would we see this same oscillation with a real, physical 50W 1 ohm resistor? I'm happy to buy you the resistor if you're willing to test it

author: EEVblog
author_rank: Unknown
timestamp: December 09, 2015, 10:56:48 am
content: Quote from: Opticalworm on December 09, 2015, 10:41:17 amAh, ok, I didn't check the processor specs.

author: dr.diesel
author_rank: Super Contributor
timestamp: December 09, 2015, 11:21:44 am
content: Mmmm,- Deceptive Corporate practices- Non standard width banana plugs- Crap quality banana plugs- Shit capsSeriously, those banana plugs? Entire instrument is a complete fail.

author: FrankBuss
author_rank: Unknown
timestamp: December 09, 2015, 11:55:08 am
content: I didn't notice the banana plugs problem, looks my Siglent SPD3303D has the same problem. With the cables I'm usually using it is no problem, but they are loose, too, with some old connectors with the slit instead of the bulges.I've done a short review of the SPD3303D, seehere. There was a major problem with the fixed voltage output, but I could patch it with the help of the Siglent support. Would be interesting if the SPD3303X has already fixed this problem. And I like the new voltage adjustment concept. Too bad that they probably won't change it for the SPD3303D anymore. Still a very nice power supply unit for the price.

author: madires
author_rank: Super Contributor
timestamp: December 09, 2015, 01:14:06 pm
content: Quote from: dr.diesel on December 09, 2015, 11:21:44 amAnd the shorted turn of the toroidal transformer. The mounting screw doesn't seem to be isolated. Rust, again. The bodged ethernet. Build quality is the same like my Mastech clone. I wouldn't pay more than €300 for that Lab PSU.

author: thomastheo
author_rank: Regular Contributor
timestamp: December 09, 2015, 01:48:17 pm
content: If they managed to overlook the fact that their binding posts don't work it really makes me wonder what else escaped their attention. That is an immediate deal breaker, i can't think of anything more basic in terms of requirements than adequate binding posts.

author: WN1X
author_rank: Unknown
timestamp: December 09, 2015, 02:02:16 pm
content: Those binding posts are absolute crap. How difficult is it to get the spacing right?!?Sorry, but my next lab supply will most likely be the Rigol DP832.

author: madires
author_rank: Super Contributor
timestamp: December 09, 2015, 02:09:17 pm
content: Quote from: thomastheo on December 09, 2015, 01:48:17 pmAbsolutely! Siglent should rework all those details already mentioned. After seeing the teardown I doubt anyone would buy that PSU. BTW, there's a little brother "-E" with a 10mV/mA resolution for €370 (SPD3303X is €509). Same issues, I'd guess.

author: c4757p
author_rank: Super Contributor
timestamp: December 09, 2015, 02:12:16 pm
content: The mains wire rubbing against the sharp chassis edge is 100% inexcusable. Italready has scratch marks! That is not something you can get away with - over time that will rub through. I'd have stopped the teardown right there and sent the thing back immediately as a fire/shock hazard.What the hell are Siglent playing at? That's not just cheap and crappy, it's downright dangerous. The engineer who did that should be fired.

author: Artlav
author_rank: Frequent Contributor
timestamp: December 09, 2015, 02:33:45 pm
content: Tangential question - what in the world would you need a power supply with such a precision for?

author: Deathwish
author_rank: Unknown
timestamp: December 09, 2015, 02:43:46 pm
content: Whats with the Siglent / Rigol comparisons all the time, it turns everything into a two horse race.The fact this one sucks worse than a two dollar hooker says it all. But at least compare it to some other brand than Rigol.

author: Robaroni
author_rank: Frequent Contributor
timestamp: December 09, 2015, 02:48:33 pm
content: Thanks Dave, nice tear down as usual.OK, the output jacks, sure they should have given us better quality - easy fix. Spacing? Not a game changer, I use supplies everyday, rarely if ever need the standard spacing but I guess they could fix it in an update but the cost would probably be high as the front panel would have to go as would the some of the internals but, again, I can live with it.Small details like the unprotected leads, easy fix. The caps? Well the only way to know if the quality is there is to push them on a test jig. I wouldn't trash them before that was done, it's not fair to Siglent, after all we don't know what their testing of components was.The screen, OK easy software fixes, not a big deal.I like the size over the DP832 series, the less room these things take on bench the better. The Rigol is a big supply about 43cm (17") in depth and I want a triple supply to limit space!My gripe is the 5 volt supply without current control. Now that can burn up some costly chips and it's something I use on a daily basis. Think about it, you have a breadboard full of components and you accidentally short outputs on a Maxim chip that goes for 10 bucks. Ouch!! I read spec sheets so when I first turn on a prototype I have current limit right above specs. And what happens if you short the 5v supply? That's one you should have tried Dave. Does it blow the soldered fuse inside the case? Now that concerns me.Size, the 1ma resolution, those are good things I like, it just needs some polish, clean up the inside of the case problems, support the TO220's and do something about the 5v current problem and I'm interested.Rob

author: FrankBuss
author_rank: Unknown
timestamp: December 09, 2015, 03:05:50 pm
content: Quote from: Robaroni on December 09, 2015, 02:48:33 pmI guess it uses the same circuit as the SPD3303D which I've tested and of course it doesn't blow the fuse if you short the 5V supply. Probably they have even fixed the nasty turn-on spike problem on this output.

author: mikron
author_rank: Contributor
timestamp: December 09, 2015, 03:14:56 pm
content: There is a screw missing ...Maybe Dave removed the PCB to check clearances?

author: free_electron
author_rank: Super Contributor
timestamp: December 09, 2015, 04:04:57 pm
content: Non standard pitch on the banana jacks ( for the bnc adapter ) -> immediate disqualification in my book. no matter how good the thing is otherwise.Sense wires ?

author: lukier
author_rank: Unknown
timestamp: December 09, 2015, 04:16:18 pm
content: Quote from: free_electron on December 09, 2015, 04:04:57 pmIf it claims to be a precision power supply I think it should have sense inputs.On the other hand there are plenty of much more expensive PSUs in the similar category (universal multi output bench type) that don't have this feature. Think HP E3631A and Rigol's clone - DP1308A. I think some other models from HP E3xxx series had them though.

author: Robaroni
author_rank: Frequent Contributor
timestamp: December 09, 2015, 04:42:48 pm
content: Quote from: FrankBuss on December 09, 2015, 03:05:50 pmThanks Frank,What's the current capacity of that supply? Like I said, I don't like a supply in 2015 that doesn't have a current regulated output. Unfamiliar caps I can live with if the quality is there and I think Dave should be less harsh on his condemnations.Basically it's a dual supply, not a triple, the DP832 is a real triple whatever other warts it might have.Rob

author: Rasz
author_rank: Super Contributor
timestamp: December 09, 2015, 04:44:47 pm
content: is there really ~1000microF output capacitance?Cant wait for excuses, 'we let flesh college graduate design this supply and source bottom of the barrel components'?

author: Monkeh
author_rank: Super Contributor
timestamp: December 09, 2015, 05:29:59 pm
content: That thing is a mess.And for a brand new product, it's interesting how the chassis is nearly identical to one I've had for years. .. and the heatsinks, and actually, the whole power PCB..Just a quick, cheap clone with a UI and some awful binding posts. Poor show, Siglent. Very poor.

author: nrxnrx
author_rank: Unknown
timestamp: December 09, 2015, 06:12:03 pm
content: Does the display really turn off after some "inactivity"? Even if it allows you to turn that off, they made it the default?I recently bought some cables (4mm banana) listed as "unbranded" but very cheap. I can't use them, but I guess they'd fit this 539USD power supply.--Mihai

author: Kevin.D
author_rank: Frequent Contributor
timestamp: December 09, 2015, 06:21:49 pm
content: The banana plugs are poor mistake, always need good quality O/P sockets considering how often they are used.Any high Voltage Mains/primary wiring and low Voltage Secondary wiring are really best kept completely seperate, with the high Voltage mains wiring having also an outer sheeth protection.Any serious bench supply needs remote sensing, I use feature often.Otherwise internal/overall construction looks fairly well done and tidy. Needs a proper review doing with load stepping.Quote from: Rasz on December 09, 2015, 04:44:47 pmNo they are 470Uf, see 17:33 in the vid, Which is still on the biggish side . Rigol dp832 is 1000uF I believe.Note at ~16:40 in the video the row of large brown ac caps (is that a 400v rating ?). These are probably the Common Mode output filter caps , these are important ( unless using an transformer with very low inter-winding capacitance) to keep common mode noise to minimum. Something that rigol dp832 completely forgot about apparently.Regards

author: John Coloccia
author_rank: Super Contributor
timestamp: December 09, 2015, 06:45:12 pm
content: Crap binding posts and non-standard spacing is all I needed to see. Geez, here I am watching this video because I'm in the market for a new power supply and I'm willing to give Siglent a chance to rehab itself, and it all goes to crap in the first 3 minutes. WTF?

author: tautech
author_rank: Super Contributor
timestamp: December 09, 2015, 06:52:23 pm
content: Quote from: nrxnrx on December 09, 2015, 06:12:03 pmAs Trio supplied this PSU, who know if it was fiddled with before Dave got his hands on it, as these have just been released it was probably their demo unit.Did Dave look at the menus for screen saver....no.Did Dave look for a default menu......no.Let's not judge to hard until he does a comparison and spends some time in the UI.As for the binding posts, I agree.

author: FrankBuss
author_rank: Unknown
timestamp: December 09, 2015, 07:14:44 pm
content: Quote from: Robaroni on December 09, 2015, 04:42:48 pmThe SPD3303D and SPD3303X have nearly the same current capacity, seehereandhere. Both are triple output power supplies. If you don't need 1 mA / 1 mV resolution (doesn't make much sense without extra sense inputs anyway for higher currents), I think the price of the SPD3303D is very good for the product, if you can live with the minor disadvantages, like that you can adjust the voltage in 1 V or 10 mV steps only, not 100 mV, and yes, the screen-saver is a default on the SPD3303D, I didn't find a way to disable it. The GUI and the construction inside looks very similar to the SPD3303X, so I guess there is no way to disable it on the SPD3303X either. Looks like the other main difference is that the SPD3303D has no ethernet. ButI've tested itand it works without problems over USB (at minute 5:00 in the video).

author: Hydrawerk
author_rank: Super Contributor
timestamp: December 09, 2015, 07:15:19 pm
content: What is the difference between SPD3303Dand SPD3303X?https://www.eevblog.com/forum/testgear/siglent-spd3303d-review/

author: Lightages
author_rank: Unknown
timestamp: December 09, 2015, 07:24:16 pm
content: Dave, I think you went a bit easy on that power supply. The bad construction techniques to on the sharp edges rubbing against the mains wire, bad binding posts and non-standard spacing, and the ultra high output capacity.... all for over $500? Sorry, its a fail.

author: Huluvu
author_rank: Regular Contributor
timestamp: December 09, 2015, 07:24:31 pm
content: they use PWBs without vias ....I cannot believe this to see it at a 600 Euro PSU.The Lelon Brand Caps are typical for Buyers keeping the BOM Cost down.

author: FrankBuss
author_rank: Unknown
timestamp: December 09, 2015, 07:30:47 pm
content: Quote from: Hydrawerk on December 09, 2015, 07:15:19 pmSee the webpages:http://www.siglent.eu/siglent-spd3303d.htmlhttp://www.siglent.eu/siglent-spd3303x-power-supply.htmlIf I didn't miss anything:SPD3303DSPD3303X3A3.2A0-30V0-32V10mV/10mA resolution1mV/1mA resolutionUSBUSB and ethernetI wouldn't pay the 209 EUR more for the SPD3303X. But for some applications the higher resolution might be useful, even if you don't get the accuracy at the end of the cable.

author: Salas
author_rank: Frequent Contributor
timestamp: December 09, 2015, 07:37:25 pm
content: Interestingly all my banana terminated chords fit well in the output posts of my SPD3303S (previous model sans network connector). Not too loose not too tight even if the banana ends are flared or ridged. Weird, because they are the same type 4mm binding posts.

author: Salas
author_rank: Frequent Contributor
timestamp: December 09, 2015, 07:49:18 pm
content: Quote from: nrxnrx on December 09, 2015, 06:12:03 pmYes, after half an hour of not pushing buttons or turning the knob.

author: bigsky
author_rank: Regular Contributor
timestamp: December 09, 2015, 07:54:13 pm
content: Dave, at 14:15, the components you say are PTCs are actually polyfuses - I could tell from the shape and googling the number confirms this - seewww.wondhope.com/pptc/WH250.html

author: Arjan Emm
author_rank: Regular Contributor
timestamp: December 09, 2015, 08:15:00 pm
content: If you can't properly connect a load to a powersupply, well, nothing else matters really. End of story. Big fail on the binding posts! Accuracy 1mA and 1mV, rather useless if it changes by 50 if you touch the banana plug. Esp. without sense connection.

author: RupertGo
author_rank: Regular Contributor
timestamp: December 09, 2015, 08:21:21 pm
content: I really don't like that slide switch on the third output. Very 70s. They've got a big ingress area for dirt and what have you, and if you brush against it while you're moving your hand around the front panel, it could easily shove 5v down your 2.5v logic. Why not a cycling push button or, even better, a proper twisty knob? Or even control it from the main input knob? I bet it can't be controlled remotely either (not that you'd normally want to).That feature looks like an afterthought.

author: Fungus
author_rank: Super Contributor
timestamp: December 09, 2015, 08:32:27 pm
content: Quote from: RupertGo on December 09, 2015, 08:21:21 pmI don't see how a button or knob is less likely to move accidentally (a knob is probablyeasier).PS: I agree with everybody else; those output posts are an instant deal breaker. How did they even get into a production PSU? Did they get a truckload of reject connectors for free...?

author: TheSteve
author_rank: Unknown
timestamp: December 09, 2015, 09:00:46 pm
content: Really seems overpriced for the quality, another Siglent product to avoid.

author: c4757p
author_rank: Super Contributor
timestamp: December 09, 2015, 09:04:18 pm
content: Quote from: blueskull on December 09, 2015, 08:41:02 pmComparable? To an all-linear? I'd like to see you pull that off.Who gives a damn about efficiency in a lab supply?

author: rdl
author_rank: Super Contributor
timestamp: December 09, 2015, 09:43:18 pm
content: Maybe hard to describe, but I didn't like the single black digit and background highlight on the display when adjusting and it looked like it never went away. If not being adjusted all numbers need to look the same.I also agree 100% as to the following physical issues, which are no buy faults in my opinion.1 Rusty sharp metal edge against mains wiring (fixable)2 Nearly useless binding posts (replaceable)3 Capacitors which can't be trusted (replaceable)3 Unsupported TO-220 devices (no easy fix, needs new pcb layout)I may have missed other issues as I lost interest around the 10 minute mark, when it became obvious this was over-priced junk.It's unbelievable to me that they would still be shipping product with factory installed rust. Because of that alone, I doubt I will waste another second looking at, or considering a Siglent product of any kind.

author: Salas
author_rank: Frequent Contributor
timestamp: December 09, 2015, 09:48:25 pm
content: Quote from: blueskull on December 09, 2015, 09:11:27 pmReminds of KORAD looks. Got to confirm on a scope it really filters out SMPS patterns across a wide band. Also find out if interference is escaping towards the AC chord or it propagates out of the box. For general use almost anything is OK until you FFT a low signal high gain circuit for instance. Rail dirt changes its noise floor grass into a jungle.

author: AF6LJ
author_rank: Unknown
timestamp: December 09, 2015, 09:51:47 pm
content: Nice $350.00US power supply.

author: c4757p
author_rank: Super Contributor
timestamp: December 09, 2015, 09:52:48 pm
content: Quote from: blueskull on December 09, 2015, 09:11:27 pmIf these things have ripple that isthatbad, then linear power supplies have got way crappier since the nice 60s-80s PDI ones I'm used to.Quote from: AF6LJ on December 09, 2015, 09:51:47 pmNice? You'd spend $350 to get some shoddy banana jacks that don't hold plugs and some mains wiring that's going to short to the chassis in a few years?Nah. This PSU put Siglent back on my shit list, actually. Releasing a product with mains wiring like that is practically malicious.

author: ErikTheNorwegian
author_rank: Frequent Contributor
timestamp: December 09, 2015, 09:57:31 pm
content: The binding posts are a killer turnoff..Dave, what about a test of this powersupplay.. killer price, done in 15 minuts to rewire it to 220V.. very popular. Its the same as HANTEK.http://www.ebay.com/itm/221885966366?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AITCircuit Specialists PPS2320A Tri Output Linear Programmable Bench Power SupplyKey Features:3 Channels (2 each 0-32 V/3A) and 1 fixed multiple output 2.5V/3.3V/5V @ 0-3A64V Max Output Voltage (32 V per Chanel)6A Max Output Current (3 A per Channel)Modes:Constant Current/Constant Voltage/SW Control/Parallel(double Current), Serial(double voltage). Split-Rail (Negative and Positive Voltage)This 3 Channel Benchtop Power Supply is a mult-functional programmable power supply featuring 2 variable outputs (0-32V/0-3Amps) and 1 fixed output channel that the user may select either 2.5V, 3.3V or 5V from 0-3 Amps. This lab grade product boasts all digital controls from the front panel or may be controlled via PC interface.

author: Macbeth
author_rank: Super Contributor
timestamp: December 09, 2015, 10:23:56 pm
content: I seem to recall there was a batch of Rigol DP832's with out of spec binding posts - they were on the smaller gauge so nobody could get their 4mm banana plugs to fit.Is there an actual international standard for these binding posts and plugs? If they don't meet it send it back.Having said that I was surprised at my recent acquisition of an ancient ESI Dekavider. The terminals are lovely, all tellurium copper, but they seem to be around 4.25mm ID and are only 0.5" deep so a banana plug sits loose and and wobbly. Just what was the standard back in the 60's?

author: langwadt
author_rank: Super Contributor
timestamp: December 09, 2015, 10:26:06 pm
content: Quote from: madires on December 09, 2015, 01:14:06 pmif the turn was really shorted you would know, a 300W transformer with a ~0.5V turn shorted, something would be glowing

author: RupertGo
author_rank: Regular Contributor
timestamp: December 09, 2015, 10:37:04 pm
content: You have to grasp a rotary switch and turn it (less so for rotary encoders with large knobs). A protruding side switch is a lot easier to accidentally activate - adjust the PSU, go to frob whatever equipment's to the right of it on the bench, and zap. On most test equipment, hitting something by accident is an inconvenience at worst - on the thing that's powering your logic, you really want more, not less, protection from fumbles.I speak from bitter experience. Also, when the BBC went from rotary mixing pots to linears on its desks, it made them fade down when you pushed them up - so that if you caught them on the cuff of your jacket when you were reaching up for the controls above them, you'd fade to silence at worse, rather than fading up something to be accidentally broadcast.

author: Armxnian
author_rank: Regular Contributor
timestamp: December 09, 2015, 10:39:53 pm
content: Quote from: AF6LJ on December 09, 2015, 09:51:47 pmIt's going to cost more for your family to pay for your funeral when you get killed by the soon to be exposed mains wiring.Seriously though, nothing has changed from the old siglent design practices. All the negatives mentioned in the video will just piss you off every time you think about it. Knowing siglent's programming prowess, setting 2v probably outputs 32.

author: Lukas
author_rank: Frequent Contributor
timestamp: December 09, 2015, 10:57:39 pm
content: Quote from: c4757p on December 09, 2015, 09:04:18 pmSize. Not needing a loud fan.Besides an SMPS you can go oldschool like keysight did with the E36100 series and use a SCR pre regulator instead of switching relays. I'm wondering why so few are doing it, since placing a dimmer on the primary side of the transformer isn't rocket science.

author: Salas
author_rank: Frequent Contributor
timestamp: December 09, 2015, 10:58:49 pm
content: Quote from: madires on December 09, 2015, 01:14:06 pmI have the big three channel Mastech with the LCD panel meters, a single channel Tenma branded Korad, and the Siglent. The Mastech after two years of use stays nowhere put for voltage setting. As faithful as Runaround Sue. Having to short the outputs to set CC & lack of output disengage button is stone age ergonomics. Frustrating. The Korad is setting fine, has memories and output button, but its back panel fan is idling out like a coffee grinder. When running some class AB amplifier 1kHz at couple of amps as load, the Korad's control loop ripples too badly. The Siglent is rock stable, has a very quiet fan that will rev up once in a blue moon, displays results in spec. Big colorful digits are great, I can always see what's going on at a distant glimpse. Got it because the Rigol is too big for my space and it screams. I hate fan noise building up when various stuff is running, it makes me wanna shut down the development work and leave. Careful testing is like reading to comprehend. It demands silence. My model (3303S) has only 0.1V or finer step through the knob firmware by now but the binding posts are fine. Exactly the same looking binding posts with the X. Can use its PC interface to punch in any setting but I would prefer 1V jumps added. I don't want to engage the PC all the time for everything.

author: mikerj
author_rank: Super Contributor
timestamp: December 09, 2015, 11:14:25 pm
content: Quote from: rs20 on December 09, 2015, 10:44:50 amIt's only irrelevant if the PSU selects a voltage tap based on measured output voltage rather than the voltage setpoint.

author: c4757p
author_rank: Super Contributor
timestamp: December 09, 2015, 11:29:33 pm
content: Quote from: Lukas on December 09, 2015, 10:57:39 pmMeh, I don't get it. If it's going on a workbench you've probably got room for a real power supply, and I never understood why fan noise bothered people. But whatever floats your boat, I guess.Quote from: blueskull on December 09, 2015, 11:00:11 pmOh for chrissake, I should have figured there was some stupid EU regulation, there usually is.Quote from: mikerj on December 09, 2015, 11:14:25 pmSelecting based on the setpoint would be completely brain-damaged design.

author: FrankBuss
author_rank: Unknown
timestamp: December 09, 2015, 11:52:42 pm
content: Quote from: AF6LJ on December 09, 2015, 09:51:47 pmThe SPD3303X costs more than $600.

author: AF6LJ
author_rank: Unknown
timestamp: December 09, 2015, 11:59:25 pm
content: Quote from: FrankBuss on December 09, 2015, 11:52:42 pmI know that post was a commentary on what I thought it was worth.I don't see anything to justify the list price for that power supply.

author: AF6LJ
author_rank: Unknown
timestamp: December 10, 2015, 12:08:23 am
content: Quote from: Armxnian on December 09, 2015, 10:39:53 pmIt wouldn't be the first piece of gear I opened up and repaired what should have fixed when it was built.QuoteThe binding posts were just the beginning.And that would be the second thing that would get fixed.The laser cut chassis reminded me of those crap computer cases that I have lacerated my hands on so many times in years past.I'm not impressed with a number of items I have seen coming out of China. They have a ways to go before they actually can build world class gear, even low end gear.

author: AF6LJ
author_rank: Unknown
timestamp: December 10, 2015, 12:11:54 am
content: Quote from: c4757p on December 09, 2015, 09:52:48 pmI would repair that stuff, and debur the sheet metal.I would also do a video on it and send a link to siglent as well as post it here.As far as the wiring goes, putting plastic tubing over the wires isn't the answer, cleaning up the edges is.There is no excuse for that.

author: langwadt
author_rank: Super Contributor
timestamp: December 10, 2015, 12:22:03 am
content: Quote from: AF6LJ on December 10, 2015, 12:11:54 ama simple zip tie would have fixed it, just zip tie it to the bundle right next to it and it never get near that sharp edge

author: c4757p
author_rank: Super Contributor
timestamp: December 10, 2015, 12:30:19 am
content: Quote from: AF6LJ on December 10, 2015, 12:11:54 amFair enough, but I'd totally flunk it in a review (yeah, I know, this was a teardown, not a review, but it gave opinions) if you had to open it up, voiding the warranty, and modify it yourself to make it safe and usable. It's supposed to be a power supply, not a power supply kit!

author: BUkitoo
author_rank: Contributor
timestamp: December 10, 2015, 12:32:18 am
content: I have the SPD3303D and I noticed that the user interface is not the best (Is just the same you are showing).When you set the parallel mode or the serial mode happens that the user interface keeps splitted in two (as two independent supplies) but, let say, in parallel mode you really want a more current capable supply, so I would prefer to have a uniffied "one channel" screen configuration. But no, you have to sum both channels maximum current to know the maximum current capability. The same happens with serial mode (summing voltages).OK, is just a software matter.

author: tautech
author_rank: Super Contributor
timestamp: December 10, 2015, 12:50:26 am
content: Quote from: BUkitoo on December 10, 2015, 12:32:18 amWe've asked them to fix that a while back, maybe they couldn't hence the new X model.

author: Smokey
author_rank: Super Contributor
timestamp: December 10, 2015, 02:06:38 am
content: If this is a new production model, So much for the "Atten isn't Siglent" argument. I can't decide if it's better or worse if it's a Siglent design rebadged as Atten or Atten design rebadged as Siglent.

author: Brumby
author_rank: Unknown
timestamp: December 10, 2015, 03:39:31 am
content: The spacing of the binding posts would be irritating, but their sloppiness is a fail. For a 1mV accuracy, it seems kinda dumb to not have sense wires. I have mixed feelings about multi-purpose knobs - but I will reserve any criticism until after having tried it out (which isn't likely)I did empathise with Dave when he reached the maximum voltage and this stupid window pops up on the screen. EXTREMELY annoying and totally unnecessary. One would assume that anyone using a lab supply would understand its limitations and work out very quickly that the maximum has been reached by the display no going any higher. If they couldn't, then I'd be anxious about them being anywhere near the gear. If Siglentreallywant to throw up a notification, then do it with a little indicator that flashes up somewhere NOT over the active information areas of the screen - and even then, only when the knob is turned to the right plus, maybe half a second. It mustn't impede operation in any way.Q. Dave:When this window pops up -1. Does it lock out any adjustment until it closes? (if so, it could find itself flying out the window real quick)2. If not, does adjusting the voltage down cause the window to disappear immediately?As for the metalwork...Quote from: AF6LJ on December 10, 2015, 12:11:54 amAbsolutely. Just get rid of the knife.

author: @rt
author_rank: Super Contributor
timestamp: December 10, 2015, 05:16:07 am
content: I'm just a scumbag, and know better than that.You should have unbolted the toroid and see what happens.It doesn't look like the work of 100 engineers to me.It would hace been interesting to open it in the presence of Yolo.

author: bitwelder
author_rank: Super Contributor
timestamp: December 10, 2015, 07:10:13 am
content: Quote from: tautech on December 09, 2015, 06:52:23 pmSometimes can be useful to check the status of the hated 'warranty void' sticker before doing a teardown

author: Bud
author_rank: Super Contributor
timestamp: December 10, 2015, 07:24:40 am
content: Quote from: Rasz on December 09, 2015, 04:44:47 pmYes it was a new young female employee who designed it when she had spare time between filing wrongful trademark claims to ebay.

author: Salas
author_rank: Frequent Contributor
timestamp: December 10, 2015, 07:47:08 am
content: GW Instek looks like having some similar functionality traits also. A cross between the X and the Hantek

author: Smokey
author_rank: Super Contributor
timestamp: December 10, 2015, 08:10:24 am
content: That select switch on the fixed voltage output is stupid. It's just stupid. There is an Arm processor on the thing and it has a Mechanical switch to select voltage outputs? Really?

author: FrankBuss
author_rank: Unknown
timestamp: December 10, 2015, 08:15:44 am
content: Quote from: Salas on December 10, 2015, 07:47:08 amEven the same 2.5V, 3.3V, 5V fixed voltage outputs. I bet it looks very much the same inside.Would be interesting to hear know who copied it from whom and if they were allowed to do this, or if it is all OEM from one manufacturer. At least the channel 1 and channel 2 numbers are swapped on the GW Instek

author: Salas
author_rank: Frequent Contributor
timestamp: December 10, 2015, 08:22:13 am
content: Could be. Siglent has its own digital control and firmware solution for the two fully fledged channels though.

author: station240
author_rank: Unknown
timestamp: December 10, 2015, 08:45:16 am
content: Quote from: langwadt on December 10, 2015, 12:22:03 amYes that's the only real fix, or glue down nylon tie points. Tubing solves nothing, as you can still trap the cable in the case when you close it.

author: Salas
author_rank: Frequent Contributor
timestamp: December 10, 2015, 09:51:16 am
content: Quote from: FrankBuss on December 10, 2015, 08:15:44 amFrankBuss, by thew way, did you see rust and burr when you reviewed the SPD3303D inside or you remember the brand of the main filter capacitors? If somewhat different in metalwork and main components choices those clues could indicate a shift of assembly resources for the X series.

author: Zbig
author_rank: Frequent Contributor
timestamp: December 10, 2015, 10:00:43 am
content: Quote from: FrankBuss on December 10, 2015, 08:15:44 amhttps://www.eevblog.com/forum/testgear/quick-look-gw-instek-gps-3303-power-supply/It seems there's one proven linear supply power stage board designed by some OEM some time, circulating among Chineese gear manufacturers. I'm not saying it's necessarily a bad thing.BTW, I have a Siglent SPD3303S I got some time ago and it has Rubycons everywhere. Too bad they seem to have gone the cost reductions way.

author: Salas
author_rank: Frequent Contributor
timestamp: December 10, 2015, 10:15:00 am
content: 3303S fellow here. Nice to know there are Rubycons inside. I did not open mine because still under warranty period. The older the better.Best value for money could be this one while its still being offered when more precise version with the screen and better DAC is not a priority.

author: Fungus
author_rank: Super Contributor
timestamp: December 10, 2015, 10:59:24 am
content: Quote from: langwadt on December 10, 2015, 12:22:03 amThat was my thought too - tie it to all that stuff two inches above it, away from the metal.Quote from: AF6LJ on December 10, 2015, 12:11:54 amNope. You could still scissor the wires if you ever took the lid off (or it could even happen on the assembly line...)Better to move the wires completely away from the metal edges.

author: German_EE
author_rank: Super Contributor
timestamp: December 10, 2015, 11:21:47 am
content: I was always taught that there should be at least two layers of insulation between a 230V conductor and the outside world, a length of heatshrink or spiral tubing would fix the problem here but has this particular requirement now fallen into disuse?As for the rust, coating the steel after it has been cut and bent to shape would cure this issue. However, the shoddy wiring, the problems with the output connections and the low quality components mean that there is no way I would recommend this product to anybody. Spacing decent quality connectors 19mm apart is not a difficult task.

author: madires
author_rank: Super Contributor
timestamp: December 10, 2015, 12:07:35 pm
content: Quote from: langwadt on December 09, 2015, 10:26:06 pmThe magnetic field is mostly whithin the toroidal core and the screw is in the middle of the toroid. My guess is that the magnetic field lines would cancel out each other in the middle of a perfect toroidal transformer. And the field strength in/around the middle should be less than directly around the core anyway. Anyone with a clamp meter and a toroidal transformer laying around? It would be really interesting to know how much power is lost in a shorted turn in the middle of the toroid.

author: FrankBuss
author_rank: Unknown
timestamp: December 10, 2015, 12:23:34 pm
content: Quote from: Salas on December 10, 2015, 09:51:16 amSee the images I linked in my first post at the end here:https://www.eevblog.com/forum/testgear/siglent-spd3303d-review/I think all capacitors were Rubycon. And yes, there was some rust, I commented one image where you can see it clearly.

author: VK3DRB
author_rank: Super Contributor
timestamp: December 10, 2015, 01:03:34 pm
content: Good tear down.Rubycon caps aren't that great. I have seen quite a few dried up Rubycons over the years, especially in TV sets.One thing you did not pick up was the terrible smudged top overlay printing on the front panel board. Their PCB makers have crap QC. For that sort of money, you would expect a quality PCB, not one where you cannot read the component identifiers because they are smudged.The screen saver might be just to do what it is supposed to do - prevent an image burning into the screen. It happens on LCD's and especially on OLEDs.The cheap-arse terminal posts are a big put off. Nothing worse that wires that don't fit or slip off cheapo terminal posts and short elsewhere. I did a linear supply back in the 80's that could provide 4.5 to 15V at 25A continuous. I used real terminal posts... fine threaded brass bolts with suitable wing nuts and a large hole in the bolt side to hold any decent wire on one axis and a small hole at right angles. Worked a treat for any wire or group of wires.I think the power supply is a little over priced for what you get.

author: Salas
author_rank: Frequent Contributor
timestamp: December 10, 2015, 01:07:09 pm
content: Quote from: FrankBuss on December 10, 2015, 12:23:34 pmThanks! Detailed pics. I had seen your video before and the circuit mods but somehow I had missed the pics.

author: AF6LJ
author_rank: Unknown
timestamp: December 10, 2015, 01:15:53 pm
content: Quote from: c4757p on December 10, 2015, 12:30:19 amI totally agree, I am working from the position I just bought this and took it apart to inspect it. Something I do quite often when I buy something, almost always if the item is used.

author: AF6LJ
author_rank: Unknown
timestamp: December 10, 2015, 01:46:11 pm
content: Quote from: Fungus on December 10, 2015, 10:59:24 amMy issue with that is dealing with the problem that way is a true band-aid fix. It doesn't address the actual problem; that being the unfinished sheet metal.A second issue I have with that part of the overall design is the mains leads running along side where screws are used to secure the cover.A third issue I have with that aspect of the design is the lack of a cable clamp to keep the mains wiring from flapping in the breeze.The above are what really needs to be done in order to bring that instroment up to what I would consider worthy of it's asking price.For extra credit; placing the mains wiring in a piece of fire retardant plastic tubing would be nice, but not really necessary, but nice.The crappy binding posts are a blatant attempt to cut costs and hope nobody will notice.As for the UI; ;it is obvious that whole UI was borrowed from somewhere else and retrofitted for use on a power supply.If they let me design it...No screen saver...I agree with Dave the unused items on the UI have to go until they are put into use.A simple color change would suffice for attempting to set the voltage outside of the operating range.One last issue;What is the point of having a precision power supply that has adjustable output voltage in one millivolt steps while having one millivolt RMS ripple and noise? This is stupid. How is the resolution meaningful if it is obfuscated by noise??

author: Deathwish
author_rank: Unknown
timestamp: December 10, 2015, 02:53:52 pm
content: As far as I am concerned the description " fit for purpose " is what matters.If it is dangerous or potentially so in any way then it is not.

author: Kalvin
author_rank: Super Contributor
timestamp: December 10, 2015, 03:05:57 pm
content: Quote from: AF6LJ on December 10, 2015, 01:46:11 pmYou can change the DC-level of that noise in one millivolt steps.Edit: Then you just state the measurement voltage was N volts +/- 1 millivolts. For example: The voltage applied was 100 millivolts +/- 1 millivolts.

author: Tek_TDS220
author_rank: Regular Contributor
timestamp: December 10, 2015, 04:27:12 pm
content: I'm in the market for a power supply, but this one is unacceptable. The cheesy power connectors, the flimsy voltage setting slide switch, the hazardous mains line with the potential to short against the chassis, bad capacitors, hot bridge diode and pass transistor.The price (~$500 US) is simply crazy for this level of quality. There are so many other options, I don't know why anyone would choose Siglent.

author: Kleinstein
author_rank: Super Contributor
timestamp: December 10, 2015, 05:49:23 pm
content: Even if the field in the center if a torroidal transformer is near zero, a turn through the center will give a voltage and possibly large current. The voltage does not depend on the field at the wire, but on the flux flowing through the loop. There a strange kind of non lokal effect in inductance, it's not the magentic field at the wire that cause the voltage.There are EU regulations for loadfactor for supplies that take more than 75 VA (If I remeber right) - but this applies to the currend drawn under usuall operation. So for audio amplifiers and lab power supplies this takes the no (or low) load current. So usually lab supplies don't have a problem with that. To meet the requirements of the higher power level, full PFC is likely needed. So just a simple linear supply will not work - even with the rather large passive PFC it gets difficult to meat the limits.Using SCR a preregulator may cause EMI problems and midium frequency (e.g. kHz range) interference which are rather difficult to filter. So a good switched mode supply may be lower noise, as filtering in the 100 kHz range is easier, but still needs some effort. There is also the option to use a kind of class H output stage - so use a BJT of FET to do the tap switching, but this needs a more complicated circuit and more filter caps and diodes.The trouble I have with the relay tap switching is, that it causes quite some current spikes. So this constant up/down switching with a tricky load can wear out the relays and possibly overload the transformer. So just a 1 V hysteresis looks like rather small. A good supply should even turn off with an error in case of constant tap switching.If a suppy is oscillation with an active load, this might be the fault of the active load. Especially the constand resistance mode seems to be done in a kind of slow software mode - so here it is likely the load that is not well behaving. Still a valid worst case test for the supply robustness, but not for the quality of regulation.

author: stranger
author_rank: Newbie
timestamp: December 10, 2015, 09:11:49 pm
content: This is clearly a fail for basic reasons, another most basic problem to add to the pile: The 1mV resolution is pointless before wondering about accuracy of the readings because Siglent have ignored the most basic calculations when they made the pigs breakfast of the terminal design.This is an incompetent product.Remember the 1mV resolution, look at the small holes in the binding posts, 12AWG may be the largest wire that goes through the hole. Assume a typical 1m wire length so a voltage drop of about 8mV per amp in each lead, so for 3A a total of 48mV dropped in the supply & ground wires. There is no point in the 1mV resolution of what the PSU thinks it is generating then delivering something VERY different to the customers application. Remote sensing capability is compulsory for accurate PSU, this PSU doesn’t do it , if Siglent want to join the serious players they need to find out what the game is.The terminal design and spacing are typical of companies that just don’t get it, the lack of remote sensing when providing high resolution as a marketing and pricing feature is hilariously revealing.

author: 0b01010011
author_rank: Regular Contributor
timestamp: December 10, 2015, 09:50:54 pm
content: Yet another issue - the UI.Timer option that no-one cares about taking 20% of the screenWhite on Cyan for editing - are you shitting meWaveform mode on the stock picture that Dave used on the web item only takes a postage stamp size of the screen, potentially one of the most useful features??They get almost all the way there on hardware and then piss all over it with crap software.

author: Tek_TDS220
author_rank: Regular Contributor
timestamp: December 10, 2015, 10:00:00 pm
content: ^^You speak the truth, stranger.

author: bitwelder
author_rank: Super Contributor
timestamp: December 10, 2015, 10:04:23 pm
content: What's that connector hanging in the breeze towards the back panel (ending a pair of orange wires) ?Something that is used only in a different PSU model?

author: Macbeth
author_rank: Super Contributor
timestamp: December 10, 2015, 10:25:13 pm
content: Quote from: 0b01010011 on December 10, 2015, 09:50:54 pmI wondered why Dave didn't try out the waveform / history modes. Then again this is just a tear down and not a review. So I guess we will get the more in depth try out of it later? Like Dave actually forces himself to use this for a while and reports back?

author: tautech
author_rank: Super Contributor
timestamp: December 10, 2015, 10:48:48 pm
content: Quote from: Macbeth on December 10, 2015, 10:25:13 pmDave should, it's incomplete until he does.

author: chris_leyson
author_rank: Super Contributor
timestamp: December 11, 2015, 12:25:56 am
content: Thanks Dave. Well, I'm not to be buying any Siglent power suppies any time soon, actually probably never.Those binding posts are crap, real crap, I bet they cost less than 1 Yuan each, or maybe 1 Yuan for the whole lot.The only nice features were the Analog Devices parts. It's a power supply with precise measurement built in and that's it PERIOD.As an analogue and RF engineer trying to make low noise measurements I don't need precision in a power supply only good isolation and low noise, same thing really, good common mode isolation is importent when making low noise measurements. It's Kirchhoffs law.For an analogue bench supply it's a big thumbs down, you lost the plot guys, it's a disgrace. There is no common mode isolation from the mains and the front panel probably has high near field emissions, go wave a magnetic probe at it if you can. Noisy power supply with multimeter built in. Big thumbs down from the anlogue guys.

author: alho
author_rank: Contributor
timestamp: December 11, 2015, 01:25:23 am
content: Don't shove the wires between pcb and casing, problem solved. No reason for them being in there. Better to zip tie them to the loom going to input voltage selection board.Will the rust really case any problems during life span of power supply? Will it rust trough the casing? Anyway I'd assume it would take decades. Not living in humid are so I don't have experience in this.I bet most of you have electric appliance with sharp sheet edges even on outside surfaces. So don't go look behind your stoves, washing machines, microwave ovens or refrigerators or you might find that you need to replace these poor quality products with more costly ones. I'd like to hear how the sales people laugh in breakroom after one of you refused to buy a stove because it has sharp edges that can get you an owie.The binding post tough thats just horrible.

author: alter Ratz
author_rank: Contributor
timestamp: December 11, 2015, 01:28:30 am
content: Quote from: German_EE on December 10, 2015, 11:21:47 amThis is not rust, its metal oxide. Must have fallen out from some leaky MOSFET.

author: stranger
author_rank: Newbie
timestamp: December 11, 2015, 10:56:22 am
content: Regarding the connector pitch on the PSU, Siglent and others might want to read this. Most instruments with dual banana plug connections follow the well established convention of using a 0.75inch mounting pitch.Why? As has been suggested it allows dual plugs to be used such as:http://www.abbatron.com/products/28-dual-instrument-test-adaptersorhttp://www.digikey.co.uk/product-search/en/connectors-interconnects/banana-and-tip-connectors-jacks-plugs/1441927?k=dual%20banana%20plugI use these for both multimeter leads and PSU connections when I need to make frequent connections. For meters when doing 4 wire Kelvin measurements it speeds connections and cuts errors. My standard low voltage multimeter leads long ago had their plugs chopped and were permanently wired into a dual plug.All my PSU and instruments of various USA, UK and Chinese brands meet the 0.75inch pitch standard which may go back 50 years, it becomes very noticeable when something does not, Japanese expression "A nail that sticks out will be hammered".

author: Fungus
author_rank: Super Contributor
timestamp: December 11, 2015, 11:59:44 am
content: Quote from: stranger on December 11, 2015, 10:56:22 amQuestion is: How can somebody in charge of designing a PSUNOTknow that.

author: Macbeth
author_rank: Super Contributor
timestamp: December 11, 2015, 12:24:10 pm
content: The worst of it is all the references to Master and Slave plastered on the front. How on earth do they think they could get any western universities or schools labs kitted out with this blatant racist triggering? Not safe space friendly at all. Even the hard disk manufacturers stopped with that racist stuff back in the IDE days when they renamed Master and Slave to Primary and Secondary. (Where's mojo to back me up on this one?)

author: Rasz
author_rank: Super Contributor
timestamp: December 11, 2015, 01:42:27 pm
content: Quote from: Fungus on December 11, 2015, 11:59:44 amits female interns fault!

author: Kleinstein
author_rank: Super Contributor
timestamp: December 11, 2015, 03:36:20 pm
content: At least the supply is consistant: ther terminals are a little to large and a little to far appart.So maybe there are dual 4.2 mm plugs somewhere in china.At least for europe the terminals have an additonal problem: they are not compatible with safty plugs (those with a fixed tube). So this supply does seem to comply with EU standards for lab equipment. If we are lucky there is a EU versions with better terminals.

author: Zbig
author_rank: Frequent Contributor
timestamp: December 11, 2015, 07:20:33 pm
content: Quote from: Macbeth on December 11, 2015, 12:24:10 pmNot exactly. There were two channels: Primary and Secondary, each of them supporting up to two devices on a single cable: a Master and a Slave, for a total of four devices. So you had a "Primary Master", "Primary Slave", "Secondary Master" and "Secondary Slave" in a maxed-out configuration.

author: Zbig
author_rank: Frequent Contributor
timestamp: December 11, 2015, 07:37:19 pm
content: Isn't it that the main justification for a standard-spaced terminals on a PSU is the ability to use a shorting bar forparallelserial/symmetrical connection? On Siglent, you don't do that as there are internal relays for that.

author: jnissen
author_rank: Regular Contributor
timestamp: December 11, 2015, 08:22:48 pm
content: Quote from: dr.diesel on December 09, 2015, 11:21:44 am100% agree!

author: Messtechniker
author_rank: Frequent Contributor
timestamp: December 12, 2015, 11:23:41 am
content: Thanks, Dave, for the teardown of the Siglent SPD 3303X. As far as I’m concernedthere is no need for a full review of this thing at the moment. I admit, I was for awhile thinking about buying it, but after these results ….This would have been my first purchase of semi-serious kit made in China.I will now forget it for the next 10 years or so.I’m looking now at the Hameg HMC 8043. I know, quite a different animal also price wise.Yours - Messtechniker

author: mjt
author_rank: Unknown
timestamp: December 12, 2015, 07:05:05 pm
content: So if there's only one AD7792 and the three outputs are isolated, how are they coupling the signal to get 5 digit precision?I'm not an electronics expert, but I thought to get good linearity through an optoisolator you need the type with two matched photodiodes (so you can do feedback) which the pc817 isn't.Or am I missing something? Do they have an ADC for each channel, or some feedback arrangement that doesn't need both photodiodes to be in the same package, or something?

author: Macbeth
author_rank: Super Contributor
timestamp: December 12, 2015, 08:25:46 pm
content: Quote from: Messtechniker on December 12, 2015, 11:23:41 amThe only real gamechanger I found (without an actual review of how it really performs) are the binding posts. Now I know the Rigol DP832 also had an issue with a batch of them with binding posts being the other way - too narrow. Perhaps this is a bad sample? The non standard spacing would be an issue if it had sense terminals that you use standard spaced shorting bars on I guess. Surely nobody uses those fixed space banana to BNC converters on PSUs?The Hameg is an instant fail because, like my Tenma 72-83xx PSUs it uses those recessed "safety" banana sockets. That is utter fail on a low voltage PSU.

author: Smokey
author_rank: Super Contributor
timestamp: December 13, 2015, 12:27:43 am
content: Quote from: Macbeth on December 12, 2015, 08:25:46 pmSurely...https://www.eevblog.com/forum/testgear/1-5in-spacing-banana-plug-to-bnc-adapter/

author: c4757p
author_rank: Super Contributor
timestamp: December 13, 2015, 12:39:59 am
content: Quote from: Macbeth on December 12, 2015, 08:25:46 pmI do. It's nicer to have one (thin) coax on the bench than two leads - especially when it'smorethan one. And why wouldn't I? That's a "standard" I thought no power supply maker would be dumb enough to go against...

author: Monkeh
author_rank: Super Contributor
timestamp: December 13, 2015, 02:15:48 am
content: Quote from: Macbeth on December 12, 2015, 08:25:46 pmI use a lot of double banana plugs.

author: Macbeth
author_rank: Super Contributor
timestamp: December 13, 2015, 03:17:00 am
content: Guess I'm wrong? I never would have thought of powering stuff up using a BNC RG58 cable and no doubt another BNC at the other end to whatever convertor going into the DC input of DUT, but it takes all sorts...?Really the wrong diameter banana sockets are of more concern. And these new EU Elfen Safety PSUs are utter shite. No binding posts at all, shrouded recessed sockets.

author: John Coloccia
author_rank: Super Contributor
timestamp: December 13, 2015, 04:02:26 am
content: I use banana to BNC all the time on a power supply, if only to monitor the voltage on a scope vs some other thing I'm looking at. I power with BNC all the time too. Most of what I do only draws a handful of milliamps...enough to fly to the moon, don't you know.It's pretty ridiculous that they can't get the binding posts and the spacing correct. I've never even given this a second thought on any other equipment I've ever used. It's just how you do it. Baffling, amateur hour kind of nonsense.

author: Tothwolf
author_rank: Regular Contributor
timestamp: December 13, 2015, 04:05:27 am
content: The unprotected mains wiring near sharp metal is inexcusable. How much would a small section of clear PVC tubing really add to the overall cost?The Rubycon capacitors in this power supply are decent parts. The ZLH series is a long life low ESR part somewhat similar to the Nichicon HE series. Rubycon's YXA series is probably closer to a Nichicon PJ or PS series and are also not bad parts.While the Lelon capacitors used as main input filters will probably last quite awhile (100Hz or 120Hz), I don't like seeing the smaller Lelon parts on the other boards. Even though 5mm or 6.3mm Lelon parts will probably last the 5 year design life of this instrument, they still aren't the high quality parts I would expect to see in a precision power supply.

author: SL4P
author_rank: Super Contributor
timestamp: December 13, 2015, 07:06:35 am
content: You mentioned the TO-220 flapping in the breeze...I also noticed the electrolytics on the front-panel PCB... some were already 'sagging' from vibration / gravity / whatever motivation.Some white epoxy-snot would fix that for virtually no effort.Added: the channel-3 switch seems a bit flimsy - perhaps a pull & slide or other mechanism would be a bit safer - esp as it's directly below the primary controls.

author: Messtechniker
author_rank: Frequent Contributor
timestamp: December 13, 2015, 08:01:11 am
content: Quote from: Macbeth on December 12, 2015, 08:25:46 pmWhy this? Just did a 4 wire measurement on a safety banana socket*with an ordinary banana plug* inserted. Measured 2.5 milliOhms.What's wrong with that?*) Used items - laying the the box for ages.

author: rs20
author_rank: Super Contributor
timestamp: December 13, 2015, 11:51:32 am
content: Quote from: Messtechniker on December 13, 2015, 08:01:11 amRecessed banana sockets are a compromise -- they're less versatile, but you're nominally safe from touching the terminals. If the terminals can't reach a dangerous voltage, then that's a fail, they're less versatile, but __________________.

author: dr.diesel
author_rank: Super Contributor
timestamp: December 13, 2015, 12:10:36 pm
content: Quote from: Messtechniker on December 12, 2015, 11:23:41 amI have one on order.Quote from: Macbeth on December 12, 2015, 08:25:46 pmI use them all the time as well.

author: NiHaoMike
author_rank: Super Contributor
timestamp: December 13, 2015, 06:58:22 pm
content: Quote from: rs20 on December 13, 2015, 11:51:32 amCould the output be floated at a high voltage? For example, you could use a 15V bench supply to run the gate drive circuit for a motor drive that is running from a mains level supply.

author: German_EE
author_rank: Super Contributor
timestamp: December 13, 2015, 08:40:02 pm
content: Try it, we'll watch from over here

author: c4757p
author_rank: Super Contributor
timestamp: December 13, 2015, 09:15:43 pm
content: Instead of having to be "protected" from your banana jacks, how about, y'know, not touching them? This isn't handheld equipment. Just don't bloody touch them while it's turned on. We can save the stupid recessed jacks for handheld devices and the Hello Kitty editions.

author: SL4P
author_rank: Super Contributor
timestamp: December 13, 2015, 09:17:53 pm
content: go have a coffee, while a trainee or your kids come into your work area.

author: c4757p
author_rank: Super Contributor
timestamp: December 13, 2015, 09:27:41 pm
content: So? Your kids could stick their fingers in a toaster or lamp socket too. Don't be a fool and leave things powered up while you walk out, if you're working with dangerous voltages.As for the trainee... what are you training for, the circus? If he doesn't understand not to touch bitey voltages he needs to repeat school, or otherwise learn the hard way

author: Brumby
author_rank: Unknown
timestamp: December 14, 2015, 01:23:24 am
content: My take on all these 'protective protocols' is that it is not intended to protect from deliberate stupidity, but to minimise the risk of accidental contact.For example, I have never in my life ever known of an instance where something conductive has slipped between a mains plug and a wall socket shorting out the active and neutral - but obviously there have been. So we now have insulated active and neutral pins. I don't really mind this because it makes sense AND that it doesn't affect usage (unlike the earlier 'shroud' on line sockets, which caused me problems with a couple of things.)My only gripe about recessed sockets is that you don't get the terminal post option, useful for securing bare wire connections. If they are trying to say we should only use 'properly terminated' cables, then I would be miffed. Trading off significant functionality for an incremental improvement in safety really rubs me up the wrong way.

author: Brumby
author_rank: Unknown
timestamp: December 14, 2015, 01:44:14 am
content: Oh, if anyone is still unsure about the question of a shorted turn on the toroidal - here's a snapshot from Dave's video:I see what looks like a nylon spacer with a moulded rim to ensure the washer nut is kept centred and right away from the mounting disc. I suspect this spacer will have a cylindrical protrusion at the rear, separating the bolt shaft and any other metalwork. In short, there is no shorted turn.Dave did point this out.

author: madires
author_rank: Super Contributor
timestamp: December 14, 2015, 10:05:00 am
content: Quote from: Brumby on December 14, 2015, 01:44:14 amYup, you're right! But it would be still an interesting experiment to find out what the impact (in numbers) of a shorted turn in the middle of the toroid would be.

author: Kleinstein
author_rank: Super Contributor
timestamp: December 14, 2015, 06:22:59 pm
content: The recessed safty conectors are useful (and in the EU required for a lab supply that deserves it's name) for low voltages too.Its not about isolation of the connectors itself, but compatibitly with new safety plugs with a fixed insulation tube.So even if the supply is low voltage this alows you to use the better cables as well and thus no more need to have the unsafe old style banana plugs or the plugs with movable shield.

author: SeanB
author_rank: Super Contributor
timestamp: December 14, 2015, 06:52:52 pm
content: Quote from: 3roomlab on December 14, 2015, 10:14:02 amAbout 10 seconds after turn on the metal will be hot enough to start melting the outer insulation, and after around 20 seconds the transformer will do an impressive arcing smoke emitting death as the primary windings short together from the inner insulation overheating and melting off. Followed by either a fuse blowing, the mains breaker tripping or the input primary wires burning out.Generally something to avoid if you can. If it is a higher than 500VA toroid it might only do all thin in under 1 second, leaving the smoking remains and a red hot metal chassis as well.If the case is aluminium it might just melt out the bolt as well with the flames and arc, and if you are lucky the anodising will provide insulation so nothing happens for a while till the oxide is punctured for some reason.

author: Fungus
author_rank: Super Contributor
timestamp: December 14, 2015, 08:32:41 pm
content: Quote from: SeanB on December 14, 2015, 06:52:52 pmWith a bit of luck you can even get a second degree burn on your hands when you grab it to try pull the plug.

author: HKJ
author_rank: Super Contributor
timestamp: December 14, 2015, 08:38:42 pm
content: Quote from: Kleinstein on December 14, 2015, 06:22:59 pmYou can get binding post that works with the shrouded banana plugs. I have that on nearly all my power supplies.

author: tautech
author_rank: Super Contributor
timestamp: December 14, 2015, 08:47:03 pm
content: Quote from: HKJ on December 14, 2015, 08:38:42 pmI'm after some of those, link please?

author: HKJ
author_rank: Super Contributor
timestamp: December 14, 2015, 08:51:07 pm
content: Quote from: tautech on December 14, 2015, 08:47:03 pmI do not know where you can buy them, but Keithley and TTi uses them.

author: Fungus
author_rank: Super Contributor
timestamp: December 14, 2015, 09:00:24 pm
content: Quote from: HKJ on December 14, 2015, 08:51:07 pmhttp://www.ebay.com/sch/i.html?_nkw=banana+shrouded+test++socket

author: tautech
author_rank: Super Contributor
timestamp: December 14, 2015, 09:08:08 pm
content: Quote from: Fungus on December 14, 2015, 09:00:24 pmSorry, no.4 mm banana shrouded socket to binding post.EditAnd with X hole

author: c4757p
author_rank: Super Contributor
timestamp: December 14, 2015, 09:15:15 pm
content: Quote from: Kleinstein on December 14, 2015, 06:22:59 pmI cut the shrouds off my cables, because they're useless. Then they fit in any banana jack. Shame we all can't just stop selling shit to the EU until they learn not to be so up themselves with regulations.

author: Monkeh
author_rank: Super Contributor
timestamp: December 14, 2015, 10:48:53 pm
content: Quote from: c4757p on December 14, 2015, 09:15:15 pmShame we all can't just stop selling shit to the US until they learn to play better with others.

author: John Coloccia
author_rank: Super Contributor
timestamp: December 14, 2015, 11:49:04 pm
content: Quote from: Monkeh on December 14, 2015, 10:48:53 pmI don't know what I'd do without all that British lab equipment.Shrouded connectors on a power supply are a fail, because all that will happen is people will create workarounds which will be far less safe than regular binding posts. No reason you can't have both, which is clearly the safest and sanest path forward in the actual real world, not the make believe world of the bureaucrat.

author: Tothwolf
author_rank: Regular Contributor
timestamp: December 15, 2015, 05:52:30 am
content: Quote from: Monkeh on December 14, 2015, 10:48:53 pmIf it would mean an end to the RoHS silliness outside of the EU then I'm all for it.

author: Unknown
author_rank: Unknown
timestamp: December 17, 2015, 01:32:51 pm
content: Just a quick note to let everyone know that the Siglent engineering team does pay attention to your comments and suggestions. They have informed us that they are addressing the SPD3303X/X-E internal wiring placement & dressing issues pointed out on Dave's video.ThanksSteve

author: German_EE
author_rank: Super Contributor
timestamp: December 17, 2015, 07:31:33 pm
content: Fixing that wiring is easy, fixing the front panel issue will probably need a new front panel, one or more new PCBs with the holes 19mm apart and a new supplier of front panel connectors.

author: Fungus
author_rank: Super Contributor
timestamp: December 17, 2015, 07:39:06 pm
content: Quote from: German_EE on December 17, 2015, 07:31:33 pmI think they were referring to "internal wiring", ie. the loose mains wires at the side that were being cut by the sharp metal.I'm not sure what he means by the "dressing issues".

author: nctnico
author_rank: Super Contributor
timestamp: December 17, 2015, 10:34:13 pm
content: Dressing of wires: cable harnesses and / or fixating

author: orin
author_rank: Frequent Contributor
timestamp: December 19, 2015, 11:16:12 pm
content: Quote from: Siglent America on December 17, 2015, 01:32:51 pmThey really need to address the binding posts - see attached picture of a SPD3303D as it arrived from Tequipment. Still haven't heard back from then what they intend to do about it...

author: orin
author_rank: Frequent Contributor
timestamp: December 20, 2015, 12:54:13 am
content: Quote from: 3roomlab on December 20, 2015, 12:34:26 amBroke at the wire hole... the holes that Dave criticized for being too small!

author: Macbeth
author_rank: Super Contributor
timestamp: December 20, 2015, 01:15:44 am
content: Quote from: orin on December 20, 2015, 12:54:13 amNot fit for purpose it appears. What are they made of, the cheapest die-cast crap painted over or what?

author: orin
author_rank: Frequent Contributor
timestamp: December 20, 2015, 03:10:02 am
content: Quote from: Macbeth on December 20, 2015, 01:15:44 amNo idea about the base metal. Shiny, so probably plated with something - nickel perhaps?

author: SeanB
author_rank: Super Contributor
timestamp: December 20, 2015, 04:38:06 am
content: Brass, but the wall thickness is so thin that it simply snapped at the thinnest part at the root of the thread, where the wall had the least area in the hole. Basically they are too thin in the wall, and need to be made larger in diameter, along with making the inner hole the correct diameter to fit the standard socket.Basically the manufacturer took too much brass off, to cut the cost of the material used in the individual item. They probably charged Siglent the cost of the length of brass used to machine the post, adding the cost of the plating as well. The manufacturers gross profit comes from the removed brass as scrap metal to be remelted, probably around $7 per kilo.

author: orin
author_rank: Frequent Contributor
timestamp: December 20, 2015, 04:59:02 am
content: Quote from: SeanB on December 20, 2015, 04:38:06 amMake a lot of sense... although now useless as a binding post, the remaining hole is still deep enough to accept a banana plug. Deep oversized hole = more removed material to scrap. If the hole wasn't so oversized, the binding post might have survived shipping!

author: madires
author_rank: Super Contributor
timestamp: December 20, 2015, 01:40:49 pm
content: Quote from: SeanB on December 20, 2015, 04:38:06 amAnd Siglent just wants to address the mains wiring issue while missing the gorilla at the front door.

author: rs20
author_rank: Super Contributor
timestamp: December 21, 2015, 10:35:11 pm
content: Quote from: ErikTheNorwegian on December 21, 2015, 09:04:58 pmEr, how do you tighten down after you've placed the wire through the hole? Or are you supposed to just poke it in there and hope?It looks more to me like that's supposed to be a right-angle banana jack hole. Sure it's not 4mm?

author: Smokey
author_rank: Super Contributor
timestamp: December 22, 2015, 01:40:08 am
content: Quote from: ErikTheNorwegian on December 21, 2015, 10:52:53 pmBut is it RoHS??

author: Circlotron
author_rank: Super Contributor
timestamp: January 09, 2016, 02:10:54 am
content: Not sure if some already mentioned it, but in Australia at least, don't the regulations require that if you can come in contact with the output of a transformer then the primary and secondary have to be segregated as is commonly done with an EI transformer? How does a toroidal measure up in this regard?

author: orin
author_rank: Frequent Contributor
timestamp: January 12, 2016, 09:52:17 pm
content: Quote from: orin on December 19, 2015, 11:16:12 pmAfter consulting with Siglent, TEquipment sent a replacement. It replacement arrived today and appears to be in good shape.A contributing factor towards the failure was immediately obvious. The dense foam packing for the replacement has a cutout for the binding posts. The original foam packing did not and obviously interfered with the binding post. Presumably they used the packing meant for the rear of the instrument at the front of this particular instrument.Orin.

author: tautech
author_rank: Super Contributor
timestamp: March 23, 2016, 10:23:08 am
content: New FW for these PSU's:http://www.siglentamerica.com/USA_website_2014/Firmware&Software/firmware/SPD3303X-P02.02R2.rar

author: hipfan75
author_rank: Newbie
timestamp: April 14, 2016, 10:34:53 pm
content: Quote from: tautech on March 23, 2016, 10:23:08 amThe UI is much improved with the new firmware. It now simultaneously displays both the set values and actual readings. I've attached a couple of photos.Regards,HipFan75

author: tautech
author_rank: Super Contributor
timestamp: April 15, 2016, 12:43:10 am
content: Quote from: hipfan75 on April 14, 2016, 10:34:53 pmWelcome to the forum.Thanks for taking the trouble to register here and offer feedback.At the time of this edit, Siglent websites had not been updated to show the new UI you've provided pics of:

author: tautech
author_rank: Super Contributor
timestamp: December 29, 2016, 08:12:27 pm
content: New Firmware for SPD3303X and X-E models.http://www.siglentamerica.com/gjjrj.aspx?id=15From the changelog:Summary of Changes:1) Add the CH3’s SCPI control command.2) Fixed a design bug about voltage setup.3) Remove the screen saver.

author: JohnG
author_rank: Frequent Contributor
timestamp: April 13, 2017, 08:34:50 pm
content: I have found a new problem with the SPD3303X-E, I think.I bought the SPD3303X-E in part because I needed to be able to control it remotely and because I have been very happy with my SGD2042X.However, I cannot reliably communicate with it. I am using Python 3.6 with Pyvisa 1.8 on a 32 bit Win 7 machine, using the latest Keysight Visa libraries, over USB. I have no problems talking to the SGD2042X, or any of my other equipment. But, I cannot talk reliably to the SPD3303X-E. If the default settings are used in Pyvisa, a supply.query('*IDN?') command times out. I got as far as finding out that it does not like the default write_termination of '\r\n', and I have to force it to '\n'. Sometimes it still seems to hang, and if I want to talk to the supply, I have to power it down and restart it.Software: 1.01.01.02.03Hardware: V3.0Like I said, no issues with the SGD2042X, or any other equipment. Disappointing, because I bought this specifically for remote control purposes. Anyone have any ideas?I would really not like to install NI-Visa to see if it works better. I have an Agilent USB-GPIB that I also need to use, and I have had repeated bad experiences with NI software, including one that required restoring my machine.Any help appreciated.John

author: tautech
author_rank: Super Contributor
timestamp: April 13, 2017, 09:21:10 pm
content: John, there are some changes coming for many instruments to allow direct control without the need for any 3rd party software. Just where the SPD3303X and X-E fit into the FW update schedule for this I yet don't know.Could the Labview drivers be of assistance in the meanwhile or do they need VISA too ?http://siglentamerica.com/gjjrj-xq.aspx?id=3619&tid=204Siglent USA have a team of techs that can look into this in detail for you.

author: FrankBuss
author_rank: Unknown
timestamp: April 13, 2017, 11:21:23 pm
content: Quote from: JohnG on April 13, 2017, 08:34:50 pmThe USB code is not the best. It works if you add delays after sending the commands:https://www.eevblog.com/forum/metrology/raspberry-pi23-logging-platform-for-voltnuts/msg1094066/#msg1094066

author: JohnG
author_rank: Frequent Contributor
timestamp: April 14, 2017, 01:53:49 am
content: Quote from: tautech on April 13, 2017, 09:21:10 pmThanks, I avoid Labview. Direct control is of less interest to me personally, because pyvisa forms a consistent framework. I have other equipment that I also communicate with, so a different method means I spend more time coding, which is not really my strength nor interest. That's just me, though, I'm sure others have probably been asking for it.Quote from: FrankBuss on April 13, 2017, 11:21:23 pmThanks for this. I was looking for something like this for a while, but didn't find it. While I don't like the slowness, it will work for now. Do you have any idea if it will be any better through a LAN connection? I have to learn how to do that anyway to talk to my scope.John

author: Unknown
author_rank: Unknown
timestamp: April 14, 2017, 05:30:56 pm
content: PM sent

author: tautech
author_rank: Super Contributor
timestamp: August 24, 2017, 08:17:00 pm
content: We now have the correct imagery on all Siglent websites showing the GUI as it is in latest firmware versions.For some time now the display has shown dialed in values AND actual real time load values.http://www.siglentamerica.com/pdxx.aspx?id=1393&T=2&tid=17

author: belba
author_rank: Contributor
timestamp: November 10, 2017, 10:06:24 pm
content: Hello,I own a Siglent SPD3303S but the Firmware is marked the Device as a SPD3303D. The power supply shows only 2 digits after a V/A value, for example 3.00V instead 3.000V.I have more Mysteries about my power supply Version:Athttp://www.siglent.com/ENs/prodcut-dbjg.aspx?Proid=529,1142,&tid=17&id=1132&T=2the difference between a 3303S and a 3303X ist the output voltage/current. A X-Model should have a max voltage at 32Volt and a max current at 3.2 Ampere, a S-Modell should have only 30 Volt and 3 Ampere.If you look at my model, I have the higher output values like the modern X-modelMy questions are following:I have Paid for a S-model but I have not the higher resolution at the display, how can I get the higher resolution?Which kind of model I own now? A SPD3303S-, SPD3303D-, SPD3303X- or a SPD3303X-E-modelI would like to have also the improved firmware too and I'm very shure, that the Hardware is not really different between the models, is there a improved firmware for my, whatever model, aviable?

author: tautech
author_rank: Super Contributor
timestamp: November 10, 2017, 10:14:18 pm
content: Quote from: belba on November 10, 2017, 10:06:24 pmThere's two very similar firmware versions for the S and D models, both are 6R2 versions.Be sure to install the S version, you can find it here:http://siglentamerica.com/gjjrj-xq.aspx?id=1223&tid=15

author: Smokey
author_rank: Super Contributor
timestamp: November 10, 2017, 11:57:28 pm
content: What is the highest rate that I can remotely change the output voltage on one channel and read the current on the other channel?For background, seehttps://www.eevblog.com/forum/testgear/rigol-dp832-remote-command-update-rate/

author: Smokey
author_rank: Super Contributor
timestamp: November 14, 2017, 12:39:32 am
content: Just one bump in case anyone knows the remote update rate of this thing...

author: tautech
author_rank: Super Contributor
timestamp: April 27, 2018, 08:27:59 pm
content: New 5 min vid on these PSU's.https://youtu.be/H-BiphMqp5g

author: hkBattousai
author_rank: Regular Contributor
timestamp: December 09, 2018, 09:23:19 am
content: Q1) What is the standard with for the banana plugs?Q2) At16:15, it is said that, for an adjustable current power supply, the output capacitors are desired to be minimum possible. What is the reason behind this?

author: alm
author_rank: Super Contributor
timestamp: December 09, 2018, 05:06:49 pm
content: Imagine you want to test a low-power LED. You set the current limit to 1 mA, and leave the voltage limit set to 30 V, since limiting the current should be sufficient. Now you connect your LED to the power supply. The output cap will be charged to 30 V, and is not subject to the current limit (it is located beyond the pass transistor). This capacitor will dump all its energy into the poor LED. The current will only be limited by the ESR of the cap, resistance in wiring etc. The bigger the cap, the more energy will be dumped in the device under test in this scenario.

author: hkBattousai
author_rank: Regular Contributor
timestamp: December 09, 2018, 07:36:03 pm
content: I understood it. Thank you very much.

author: rolfdegen
author_rank: Regular Contributor
timestamp: March 10, 2020, 05:38:55 pm
content: Hello..The Siglent SPD3303X-E laboratory power supply arrived today. What can I say ... I'm verry happy.The Siglent power supply is super quiet. In addition to Rigol DP321 power supply, you can now work relaxedand even listen to musicI just don't understand why the Rigol DP831 power supply is so loud after being switched onAfter switching on, the fan starts up and then constantly at medium speed.Perhaps the power transistors in the power supply are "preheated" like in the diesel before the startConclusion: Although the Rigol DP831 power supply compared to the Siglent laboratory power supply more adjustmentand Possesses analysis functions (even a system temperature display), I will ultimatelyopt for the Siglent laboratory power supply and send the other one back.Greetings Rolf

author: oz2cpu
author_rank: Frequent Contributor
timestamp: March 05, 2021, 06:57:06 pm
content: comments to the #828 videothe 2020 version : banana connectors now with correct hole.the wires are now secured with cable ties,the too hot bridge rectifier is now 56C,no more screensaver,both setpoint and actual are displayed at same time.idle power usage 12W all outputs off.

author: tautech
author_rank: Super Contributor
timestamp: March 05, 2021, 08:24:02 pm
content: Quote from: oz2cpu on March 05, 2021, 06:57:06 pmNice, hadn't noticed the binding posts had been shifted 1mm.Do install the latest FW for the new features added:Add the OCP function (Long push the right arrow button (’→’) get into or exit OCP function).Different font colors when the power is ON and OFF.Some improvements about the USB’s stability.

author: tautech
author_rank: Super Contributor
timestamp: March 06, 2021, 02:07:46 am
content: Quote from: tautech on March 05, 2021, 08:24:02 pmDeeper investigation shows recent stock of SN# SPD3XIDD4R54** units still have 20mm spacings.Do you have a later SN# unit ?

author: oz2cpu
author_rank: Frequent Contributor
timestamp: March 06, 2021, 11:13:27 am
content: i dont care much about the spacing, why would i ?it is the HOLE that David complain about, it was too large in his very erly demo unit,so his chepo crapy banana plugs did not mate correctly,I tried all types of banana plugs and cables i could find here,all go tight and firmly, and there is always a perfect good and stable connection,I dont own any banana plugs as low quality as the types David used.

author: rs20
author_rank: Super Contributor
timestamp: March 08, 2021, 10:42:05 am
content: Quote from: oz2cpu on March 06, 2021, 11:13:27 ametc

author: oz2cpu
author_rank: Frequent Contributor
timestamp: May 04, 2021, 06:03:28 pm
content: i dont own or use any of the pictured connectors, since they are all compleetly useless for my lab needs.by the way : I am still super happy about my SPD3303X

author: oz2cpu
author_rank: Frequent Contributor
timestamp: August 19, 2022, 07:23:40 am
content: EMI issues ?? this is a nice linear supply, so it is not a switchmode,BUT it contain a lot of digital ic's microcontrollers ethernet usb display, see this video for a short EMI infohttps://youtu.be/AhA_7adw9fA

author: pfabri
author_rank: Newbie
timestamp: December 01, 2022, 12:10:27 pm
content: That looks pretty bad.