Siglent SPD3303C Series Programmable DC Power Supply, Siglent fails to respond - Page 1
Forum section: electronics / testgear

author: cos
author_rank: Contributor
timestamp: June 22, 2023, 06:51:45 am
content: Ref.1: Siglent SPD3303C Series Programmable DC Power Supply Quick Start QS0503C-E01B dated 2014.Ref.2: Siglent SPD3303C Series Programmable DC Power Supply Quick Start EN-02A.Ref.3: Siglent SPD3303C Programmable DC Power Supply Service Manual SM0503C-E01A dated 2017.Ref.4: Siglent SPD3303C Firmware Revision History and Upgrade Instructions, Revision History page 1of 1.Below are my observations and questions I sent to Siglent regarding this power supply. Despite several promises that they would come back on this, it is now December 2023 and up to now they failed to respond. That's no good service.I purchased a SPD3303C in november 2022.Checking the mains input I found a quality control issue. Furthermore the HW version is not marked on the unit, there are documentation issues and I found a software bug.Having sent these and other observations to Siglent.eu on 13 december 2022 and having asked about the progress twice, now more than half a year later they still have not provided any answer to my questions.My observations and questions are shown below, maybe they are of some help for other users/prospective buyers.Power InputThe unit was set for 220V mains voltage, I changed that to 230V.However the active fuse was T6.3A/250V which is for 100V/120V mains voltage.I would expect that when set for 220V, it would also have the associated fuse installed which was clearly not the case.Maybe this was caused by confusion as the fuse labeling on the rear panel of the instrument has no clear division between the mains voltages and the fuse ratings, see attached photo "Fuse Selection".A vertical dividing line might solve this.Although chapter "General Safety Summary" of Ref.1 enclosed in the packaging box has a section "Use the proper fuse", specifying the correct relation of fuse values and mains voltages there is no check for this in Chapter 1, section "Safety Considerations" para "Input Power Requirement".Note: The same applies for Ref.2.Anyway, the spare section of the fuse holder contained a T3.15A/250V fuse. I swapped both fuses and will replace the T6.3A/250V by a second T3.15A/250V fuse.Please advise whether a unit set for 220V should be equipped with two T3.15A/250V fuses.I checked the voltage and current outputs for CH1 and CH2 per Ref.3 and they were well within limits.However I failed to notice tests for CH3 and the later added OCP function.Please advise whether this is correct.Hardware (HW) and Firmware (FW) identifications of the unitThe Firmware Release Notes on the Siglent site consist of a Revision History (1 page), see attachment (Ref.4).According to this document there are two hardware versions V1.0 and V2.0.Please advise the differences. Are circuit diagrams available?As the units leave the factory in a fixed HW configuration, why is that not shown on the unit?Firmware version 1.02.01.02.02 only supports HW V2.0. According to step 1.C. Apparently the "NO.1~5" button is used to determine whether the HW is V2.0.No explicit mention is made however what the display looks like when the HW is V1.0. Please advise.It is also not clear whether the EasyPower P20 version is needed to detect this "NO.1~5" button function. Please advise.Note: This "NO.1~5" button function is not mentioned in refs 1 and 2.I used the EasyPower P20 version without problems but is it to be used with older FW versions? Please advise.Note: later I reverted to P18, just to be sure.Using EasyPower, two commands are available to find configuration data:- SYSTEM:VERSION? = Query the software version.Before I updated the firmware it showed: 1. 02. 01. 01. 03R9 and there after: 1. 02. 01. 01. 03R10.- *IDN? = Query the manufacturer, product model, series NO. and software version.Before I updated the firmware it showed: Siglent Technologies, SPD3303C, SPD3EEEX6R1140, 1. 02. 01. 01. 03R9, V1.3 and there after: Siglent Technologies, SPD3303C, SPD3EEEX6R1140, 1. 02. 01. 01. 03R10, V1.5.The hardware cannot be changed by the update and these additions do not show up in the results of the software version queries.Please advise the meaning of the additional V1.3 and V1.5.Please note that in the Easy Power CmdControlDlg display for the two queries shown above the left/right and up/down arrows do not function, the PC mouse has to be used in the shown text (I did not try the other possibilities).Please advise why 1. 02. 01. 01. 03R9 is not shown in the ref.4 revision history. Are there other missing versions?Over Current Protection (OCP)According to ref.1.4 this function was introduced with FW update 1. 02. 01. 01. 03R10.It gave meaning to the "----- Long Push" text above the CH3 voltage selection slide switch of the unit.Ref.1 does not mention this function, Ref.3 does.Please advise whether this function was already present in FW version 1. 02. 01. 01. 03R9 (the "----- Long Push" text is on my 1. 02. 01. 01. 03R9 unit) .The description in Ref.2 does not fully describe the limitations of this function, my observations are as follows:1) the OCP function only works when the set OCP value is less than the set CC value.2) the OCP function does not limit over current in amplitude but only in time: it switches the output OFF after a delay of several hundreds milliseconds (observed up to 410 ms), during which the CC current flows.E.g. when CV and CC are set @ 32.00V and 3.00A and OCP @ 0.9A and the output is switched on into a 1 ohm load, the output capacitor(s) rapidly discharge, yielding a spike of 6.28A where after the 3A CC flows for approx. 325 ms as measured over the 1 ohm load, see attached DS1Z_QuickPrints 77 and 78.3) OCP settings can only be made when both the CH1 and the CH2 are OFF. Then a long press of the "A" button yields OCP in the voltage field of the selected channel and the OCP value can be set using the rotary control.When in that situation the selected channel is changed the OCP value can be set for the then selected channel. When ready, a long press of the "A" button cancels the OCP setting mode.4) when OCP has activated due to an overload, the display shows "O.L" (overload).5) When upon selection of the OCP mode the "A" button is held, the OCP setting display and "A" button illumination start cycling OFF/ON as long as the button is held.6) When in OCP setting modus CH1 and/or CH2 is/are selected ON, the OCP setting mode is cancelled and the display returns to normal.There is however a situation in the OCP setting function which I consider to be a bug.When the "V" voltage selection button is illuminated and the "A" button is pressed until OCP shows up on the display, the "A" button does not yet illuminate (for that it must be held significantly longer) and the "V" button remains illuminated. When then CH1 and/or CH2 is/are selected ON, the OCP setting mode is cancelled but the rotary control now adjusts the CC current of the selected channel while the "V" button still is illuminated!This remains so when the output(s) is(are) switched OFF and can be solved by selecting the other channel or selecting the "A" button.This may be solved by ensuring that when the OCP setting function activates, the "A" button illuminates simultaneously.Default Display SettingsRefs. 1 and 2 note under "Safety Considerations" para "Electrical Check" step 2 that the system must return to the default settings after a while.I failed to find the default setting however.Please advise where these default settings are shown and how they depend on the FW version.Note: After installation of FW 1. 02. 01. 01. 03R10, I find the following: "CH1" and "V" buttons illuminated, displayed values 5.00V and 0.40A.If I remember correctly, the latter were 0.00V and 0.00A with FW version 1. 02. 01. 01. 03R9.No Load Display Behaviour with Current set to 0.00When the current of CH1 and CH2 has been set to 0.00 and the outputs are switched ON, CH1 voltage and current go to 0.00V and 0.00/1A respectively, CC light ON.However for CH2 the voltage initially drops to zero (CC light ON) but then increases towards the selected voltage again, CV light on.This difference may be confusing.Am I correct to assume this is normal behaviour and implicitly covered by refs 1 and 2 step (1) of "Output voltage checking"?With FW 1. 02. 01. 01. 03R10 default current values are 0.40A, so there it should be less of a problem.Output OFF voltagesWhen the outputs are not on, the following values are measured:- Voltages:CH1: -14.886 mV; CH2: -14.454 mV; CH3: -0.22 mV.- Currents:CH1: -15.3uA; CH2: -14.9 uA; CH3: -0.23 uA.Is this correct? Having no circuit diagram, I can't verify whether this is normal or not.Error in Measured Voltage ValuesAlthough it is within the specified accuracies, I noted the following (CH1 and CH2 outputs switched ON, no load).1) When the output OFF voltage has been set to 0.00V (current set to 0.1A), the CH1 displayed output ON voltage becomes 0.01 and cannot be reduced to 0.00 using the rotary control (the actual output voltage was -3.4 mV).2) with 0.10V/0.10A set and the output then switched on, the CH2 displayed voltage became 0.09 which agreed with the measured output voltage (93.3 mV). Turning the rotary control 1 fine step up increased the measured output voltage to 103.4 mV which is good but the displayed value remained at 0.09V. Increasing one more fine step the measured output voltage became 113.4 mV and the display jumped to 0.11V. So it skipped 0.10V at the first fine step.Similar behaviour of the displayed output voltage was noted at other set voltages.Is it correct to assume that this falls within the + 2 digits display accuracy specification?Transformer steppingSometimes the steps of transformer switching are not visible in the output voltage, sometimes they are. See see attached DS1Z_QuickPrints 57 and 61.Please advise whether this is normal operation.Reduction of Max.Output Series VoltageRef.1 was provided with my SPD3303C unit which had FW version 1. 02. 01. 01. 03R9.With FW version 1. 02. 01. 01. 03R6 the maximum series output voltage was reduced to 60V.However in ref.1 the maximum series output voltage is still shown to be 64V.Mains HumWith no significant load the unit sometimes hums (not very loud). I assume this is the power transformer.With no loads applied and the unit turned on, I varied the voltage 230V + 10% from 207V to 253V.The input current varied from 55 mA to 63 mA, input power from 9,16W to 12,00W.Please advise whether these are normal values or is there some core saturation?

author: 7thSenpai
author_rank: Contributor
timestamp: December 28, 2023, 12:59:55 am
content: Reviving this issue apologies to all,I made the mistake to update my firmware to 1. 02. 01. 01. 03R10. I too had 1. 02. 01. 01. 03R9. R10 does not recall last state after power cycle. I am now downgraded to R6 to retain this feature, unfortunate.Does anyone have 1. 02. 01. 01. 03R9 firmware for download somewhere? I am also trying to contact siglent to get my original firmware revision back but I really can't count on them seeing how these updates are just bogus - introducing bugs rather then fixes!

author: cos
author_rank: Contributor
timestamp: December 28, 2023, 09:50:58 am
content: I am afraid that we have been supplied with a unit that had unreleased software.Version 1.02.01.01.03R9 is not shown in the Siglent SPD3303C Firmware Revision History, see attached pdf.They jump directly from 03R6 to 03R10.Wonder whether there are also units around with 03R7 and 03R8.Even when not, they should all be listed in the revision history and marked appropiately.Assume Siglent doesn't bother supporting their previous HW-version units. But as the HW-version is not marked on the unit and they are apparently still on the market, one should be very cautious when considering buying a SPD3303C.

author: 7thSenpai
author_rank: Contributor
timestamp: December 28, 2023, 03:50:46 pm
content: I'm fairly certain that the new hardware version is detectable by holding the no.1~5 button. The new hardware will indicate 2.0 whereas hardware version 1 will not do anything. Firmware incompatibilities will mean vise-versa meaning unlikely any new hardware revision boards will have 1.02.01.01.xx firmwares. But yes if you are on the market for one of these PS probably is wise to make sure its hardware version 2

author: cos
author_rank: Contributor
timestamp: December 28, 2023, 06:41:36 pm
content: Definately. The issue is that when one orders this unit, there is no way of finding out whether it is an old or a new HW-version.It is not discernible from the identification of the unit.For that it has to be unboxed, powered up and then holding the no.1~5 button. Seems like a great task for the sellers. But then it is an open box unit.....Looks to me that Siglent has to improve their configuration control.If they want to sell various HW-versions under the same model #, they should provide support for all those versions.

author: 7thSenpai
author_rank: Contributor
timestamp: January 14, 2024, 09:53:23 pm
content: Welp after they asked me my contact information it seems I'm not important enough to give me any status update or any means of reply over 2 weeks now. In other words I think its tough luck, for myself and for those who upgraded to newest firmware with hardware revision 1 and now have to live with a older firmware with less features.This is just a update for those that might are waiting for the solution.

author: rf-loop
author_rank: Super Contributor
timestamp: January 15, 2024, 06:30:23 am
content: Quote from: cos on June 22, 2023, 06:51:45 amFirst you tell you have sent to Siglent (manufacturer)And next you tell you have sent to Siglent.euSiglent.eu is not Siglent! This is just one random distributor.This (https://www.siglenteu.com/) is real Siglent ( manufacturer's European Office )Of course, it would have been good for the dealer to advise you to contact the manufacturer's support if he himself can not handle this. In my opinion, the manufacturer should also place more obligations on the level of technical support of the dealers. Such careless action does not improve the manufacturer's reputation without the manufacturer being to blame.

author: tautech
author_rank: Super Contributor
timestamp: January 15, 2024, 08:41:17 am
content: Latest FW from Nov '23https://int.siglent.com/upload_file/zip/firmware/Power_Supply/SPD3303C_V1.02.01.02.02R3_EN.zipSource:https://int.siglent.com/download/firmwares/?ProId=43

author: rf-loop
author_rank: Super Contributor
timestamp: January 15, 2024, 10:21:25 am
content: Quote from: tautech on January 15, 2024, 08:41:17 amAFAIK: For V1 HW version (as OP have)... latest supported FW is 1.02.01.01.03R10 (published 2022/6/8)

author: cos
author_rank: Contributor
timestamp: January 15, 2024, 06:50:59 pm
content: @ rf-loopNo worries:When I type "Siglent" into my browser, I gethttps://www.siglenteu.com/I sent my initial questions and observations to: info-eu@siglent.comThey forwarded it to support-eu@siglent.com for investigation and requested them to forward it to R&D if there are FW bugs or improvement suggestions.Since then, it has stalled.

author: 7thSenpai
author_rank: Contributor
timestamp: January 15, 2024, 10:56:40 pm
content: Any chance you can get firmware 1.02.01.01.03R9 (firmware that is shipped with units around a year ago) for us folks with hardware rev 1? 1.02.01.01.03R10 is full of worms.

author: cos
author_rank: Contributor
timestamp: January 16, 2024, 09:31:37 am
content: This morning I asked again about my questions.Also asked whether they can provide SPD3303C Firmware - 1. 02. 01. 01. 03R9 and describe what the changes are with respect to 1. 02. 01. 01. 03R6.

author: slugrustle
author_rank: Frequent Contributor
timestamp: January 16, 2024, 06:54:31 pm
content: I can guarantee that if your enquiry to Siglent was as long as your original post here, they didn't read it.This would apply for pretty much any company, not just Siglent. I'm only saying that this is likely the case, not that it's a good situation.If they still don't reply, try again but keep it to the most important 1-3 issues with one short bullet point each, say you can provide more details, and let them ask for the details.

author: cos
author_rank: Contributor
timestamp: January 19, 2024, 10:43:14 am
content: Good suggestion, thank you.

author: cos
author_rank: Contributor
timestamp: January 19, 2024, 10:47:31 am
content: Quote from: 7thSenpai on January 15, 2024, 10:56:40 pmPlease describe the "worms" you found. May be helpful for problem solving.Thank you.

author: nctnico
author_rank: Super Contributor
timestamp: January 19, 2024, 10:48:21 am
content: A better course of action would have been to return the power supply and buy a different one. If it is still under warranty, I'd return it for a refund.

author: 7thSenpai
author_rank: Contributor
timestamp: January 20, 2024, 02:44:33 pm
content: Quote from: cos on January 19, 2024, 10:47:31 amSorry I really ment to reply to Tautech as Im not very forum savvy (I needed to quote). I believe he has some kind of affinity with Siglent's team from reading some other posts.I didn't bother to do any serious test to report. The "worms" was really ment as whatever issues was raised in the OP here (by you) plus my main issue, which I will try explain in better detail - to me is a deal breaker forces me to revert to R6.All firmware I mention is based on 1.02.01.01.03XX Hardware Revision 1-Settings go back to default after power cycle in R10. The default setting is 5.00V and 0.40A in R10. Previous versions ( R9 and below ) last voltage and current setting are recalled after a power down and power up cycle. There was no mentions in the firmware notes that says it will change this, and why even lose this feature?-At some firmware revision point below R6 somewhere, max voltage in Series Mode went from 32V / ch. to 30V / ch. I cannot verify this however, mine was shipped with R9 and has always been 30V / ch. in Series. I had a lot of confusions when I got this unit seeing this power supply was used in some audio amplifier based youtube channel (John Audio Tech) where he can set it to 32V / ch. Is this is bug? Not sure but I was under the impression I will be able to do 64V, this is not that big of a deal to me, but even going through the specsheet now doesn't bother to mention this limitation, and really why should it be limited to 30V / ch. in Series Mode? I can go around this by going back to independent mode to 32V. / ch and wiring it up but not the point.I have still have not received any more replies from Siglent NA. I'm not expecting them to anymore really because I don't wish to spend any more time with this problem. Solution is return if I was able to, which I am not. Or look for a new power supply which I will eventually do. R6 will have to do for couple years.

author: electr_peter
author_rank: Unknown
timestamp: January 20, 2024, 05:02:06 pm
content: Quote from: cos on June 22, 2023, 06:51:45 amI can confirm that older SPD3303C unit was set to 230VAC, but active fuse was 6.3A. 3.15A fuse was in holder as well, so it is an easy change.

author: slugrustle
author_rank: Frequent Contributor
timestamp: January 21, 2024, 06:35:00 pm
content: Quote from: 7thSenpai on January 20, 2024, 02:44:33 pmI noticed this on my SPD3303C (version 1 hardware) after upgrading to 1.02.01.01.03R10. That bugged me, but I also wondered if my memory of previous operation was mistaken. I resorted to saving my settings as preset #1 and reloading on startup. I tend to keep the same settings for a while with the testing that I do.Quote from: 7thSenpai on January 20, 2024, 02:44:33 pmThe firmware release notes athttps://siglentna.com/wp-content/uploads/dlm_uploads/2023/11/SPD3303C-Firmware-Revision-History.pdfsay that the 60V limit was applied in version 1.02.01.01.03R6.Regulatory compliance is the likely reason for this update. 60VDC is cited as the touch safe DC voltage limit in a dry environment in some regulatory standards (UL, IEC, etc.). I don't have access to these documents outside of work, but if memory serves, at least some of them have that limit. I don't see a regulatory standard listed in any of the documentation for the SPD3303C, but going on a manual for another power supply and the presence of a CE mark on the SPD3303C, my best guess is they constructed it to IEC 61010-1.

author: slugrustle
author_rank: Frequent Contributor
timestamp: January 21, 2024, 06:52:30 pm
content: While I really like the SPD3303C, and the value for money is very hard to beat, one thing bothers me the most about it: On a couple of occasions, I have had the supply switch to random settings after accidentally shocking it with ESD while plugging something in or pressing a button. I now am careful to always wear an ESD strap when operating the SPD3303C, even I'm only touching the supply itself and not the circuits that I'm testing.

author: 7thSenpai
author_rank: Contributor
timestamp: January 23, 2024, 01:39:34 am
content: Quote from: slugrustle on January 21, 2024, 06:35:00 pmGot ya.I suppose manually wire them in series to get 64V is in regulation.. whatever keeps regulation happy.Quote from: slugrustle on January 21, 2024, 06:52:30 pmBeen covered here I had same issues, its a known issuehttps://www.youtube.com/watch?v=KkbVq94F688.I would have imagined with ESD the output caps would absorb it (220uF 50V caps on the output) so I feel like something else is going on. I have voided my warranty and found that the 3.3V / 5V regulators run quite hot enough to leave brown discolorations underneath the chassis. Not so impressed seeing them regulators without heatsinks.