New Siglent SPD4000X series power supply

[dirtcooker]

The SPD4323X has most of the features I am looking for except one. It seems to be missing a dual tracking feature. If you put channels 2 and 3 in series, the manual states
"In the series mode, the voltage value is twice compared with that of single channel. CH2/3 are linked internally into one channel which is controlled by CH2, and CH2 reads the parallel (sic) voltage and current values.
...
3.Connect the load to the terminals on the front panel: CH2+ & CH3-. "
So what if your using this as a +- supply, and you want to know the +- currents, and possibly set different values. Am I missing something? Does anyone have one of theses to check?

[tautech]

The SPD4323X has most of the features I am looking for except one. It seems to be missing a dual tracking feature. If you put channels 2 and 3 in series, the manual states
"In the series mode, the voltage value is twice compared with that of single channel. CH2/3 are linked internally into one channel which is controlled by CH2, and CH2 reads the parallel (sic) voltage and current values.
...
3.Connect the load to the terminals on the front panel: CH2+ & CH3-. "
So what if your using this as a +- supply, and you want to know the +- currents, and possibly set different values. Am I missing something? Does anyone have one of theses to check?

SPD3303X in Series mode works as a + dual tracking PSU and I don't see why SPD4000X won't too.
Just take your 0V from one of the center terminals.

ie, the Neg of Ch2/Pos Ch3 becomes the 0V rail and Ch2 Pos is + supply, Ch3 - is the negative supply.
You can also setup something similar with an external link in independant output mode and limit the current on each rail.

I'll have some SPD4000X in the next few weeks to confirm.

[dirtcooker]

"SPD3303X in Series mode works as a + dual tracking PSU and I don't see why SPD4000X won't too."
makes sense that it would. But I am wondering if the current/voltage readback is disabled for CH3 when in series mode. The manual states: “4W sense mode is not supported in series or parallel mode.” I wonder why not.
I am comparing this model to the Instek GPP-4323 and the Keysight E36313A (which of course is 3x the price of this) Reportedly with the instek: “one of the main channels reads 3.3mA, the other 2.2mA even if nothing is connected to the output” (https://www.eevblog.com/forum/testgear/gw-instek-gpp-4323-422471/msg5426795/#msg5426795)
That would be unacceptable. I'm working on a battery powered device so I want the meter readings to be accurate.

[tautech]

"SPD3303X in Series mode works as a + dual tracking PSU and I don't see why SPD4000X won't too."
makes sense that it would.
But I am wondering if the current/voltage readback is disabled for CH3 when in series mode.

It's not in the 3000X models, Ch1 is the master control but they track together.
We need somebody with one to perform some tests for you.....
Have you tried your local guys ?
Kemp Instruments
 972-437-9100
 www.kempinstruments.com
 dallas@kempinstruments.com

Or maybe call NA HQ and have a chat to a tech there:
Siglent Technologies NA, Inc.
6557 Cochran Rd Solon, Ohio 44139
Tel: 440-398-5800
Toll Free:877-515-5551

The manual states: “4W sense mode is not supported in series or parallel mode.” I wonder why not.

Good find and makes sense.
How would it be configured into the existing rear Sense inputs ?

[Furna]

We need somebody with one to perform some tests for you.....

I have a SPD4121X ... let me know exactly what test you would like to be performed and I will try ...

I'll have some SPD4000X in the next few weeks to confirm.

Will be good to make some confrontation ... what I am seeing on CH1 and CH4 is "unexpected" and before posting I would like to have some confirmation.

[dirtcooker]

I have a SPD4121X ... let me know exactly what test you would like to be performed and I will try ...
[/quote]

With Ch2 and CH3 in series mode and set to, say, 5v each, place a 100 ohm resistor across CH2 and a 50 ohm resistor across CH3. the current in CH2 should read 50ma and in CH3 should be 100ma. Now set the current limit to 50ma. what is the voltage across ch2 and across ch3? the Voltages should track.

[dirtcooker]

"SPD3303X in Series mode works as a + dual tracking PSU and I don't see why SPD4000X won't too."
makes sense that it would.
But I am wondering if the current/voltage readback is disabled for CH3 when in series mode.

It's not in the 3000X models, Ch1 is the master control but they track together.
We need somebody with one to perform some tests for you.....
Have you tried your local guys ?
Kemp Instruments
 972-437-9100
 www.kempinstruments.com
 dallas@kempinstruments.com

Or maybe call NA HQ and have a chat to a tech there:
Siglent Technologies NA, Inc.
6557 Cochran Rd Solon, Ohio 44139
Tel: 440-398-5800
Toll Free:877-515-5551

The manual states: “4W sense mode is not supported in series or parallel mode.” I wonder why not.

Good find and makes sense.
How would it be configured into the existing rear Sense inputs ?

CH2 and 3 sense inputs would be connected across the loads as usual. Why wouldn't 4W sense be available in a dual tracking power supply? CH2 and 3 are independent and fully floating, and 4W sense would complete the feedback loop to compensate for cable loss.

[tautech]

We need somebody with one to perform some tests for you.....

I have a SPD4121X ... let me know exactly what test you would like to be performed and I will try ...

Engage Series mode (for Ch2&3)
Adjust any parameter and observe Set values for these 2 channels, they should track.

Confirm with DMM measurements between Ch2 Pos, Ch2 Neg/Ch3 Pos (0V) and Ch3 Neg provides a dual polarity tracking supply.

Exit Series mode
Fit link between Ch2 Neg/Ch3 Pos and confirm link as 0V and each channel can be adjusted independently for a non-equal + supply with V and A independently adjustable.
TIA

[tautech]

"SPD3303X in Series mode works as a + dual tracking PSU and I don't see why SPD4000X won't too."
makes sense that it would.
But I am wondering if the current/voltage readback is disabled for CH3 when in series mode.

It's not in the 3000X models, Ch1 is the master control but they track together.
We need somebody with one to perform some tests for you.....
Have you tried your local guys ?
Kemp Instruments
 972-437-9100
 www.kempinstruments.com
 dallas@kempinstruments.com

Or maybe call NA HQ and have a chat to a tech there:
Siglent Technologies NA, Inc.
6557 Cochran Rd Solon, Ohio 44139
Tel: 440-398-5800
Toll Free:877-515-5551

The manual states: “4W sense mode is not supported in series or parallel mode.” I wonder why not.

Good find and makes sense.
How would it be configured into the existing rear Sense inputs ?

CH2 and 3 sense inputs would be connected across the loads as usual. Why wouldn't 4W sense be available in a dual tracking power supply? CH2 and 3 are independent and fully floating, and 4W sense would complete the feedback loop to compensate for cable loss.

Not when in Series mode.

[dirtcooker]

Not when in Series mode.

yes, and that's why I think it does not have a dual tracking mode. series mode is simply intended to double the voltage capability, as the manual says "CH2/3 are linked internally into one channel which is controlled by CH2". The keysight has 4 modes: auto series, auto parallel, independent, and tracking. I will check with my local NA distributor, good idea. I hope I'm wrong. I really like Siglent gear and have bought a lot of it. Great engineering, build quality and value for money.

[tautech]

Not when in Series mode.

yes, and that's why I think it does not have a dual tracking mode. series mode is simply intended to double the voltage capability, as the manual says "CH2/3 are linked internally into one channel which is controlled by CH2".

While not specifically called a Dual tracking mode, while in Series mode and the center point tapped off as 0V, they behave as a dual tracking PSU.

I wondered about this a while back and dragged out a SPD3303X to check.....

[dirtcooker]

Not when in Series mode.

yes, and that's why I think it does not have a dual tracking mode. series mode is simply intended to double the voltage capability, as the manual says "CH2/3 are linked internally into one channel which is controlled by CH2".

While not specifically called a Dual tracking mode, while in Series mode and the center point tapped off as 0V, they behave as a dual tracking PSU.

I wondered about this a while back and dragged out a SPD3303X to check.....

The difference is that now there are relays inside that connect the outputs in series or parallel, which is a nice feature. The keysight does this too and that is why it has 4 distinct modes.

[tautech]

Not when in Series mode.

yes, and that's why I think it does not have a dual tracking mode. series mode is simply intended to double the voltage capability, as the manual says "CH2/3 are linked internally into one channel which is controlled by CH2".

While not specifically called a Dual tracking mode, while in Series mode and the center point tapped off as 0V, they behave as a dual tracking PSU.

I wondered about this a while back and dragged out a SPD3303X to check.....

The difference is that now there are relays inside that connect the outputs in series or parallel, which is a nice feature.

FYI
All multichannel SPD models use internal relays for Series and Parallel modes.

[Furna]

Unfortunately I have no time to write down here the results, but I wanted to share asap and hopefully images below are self explanayory.
Will be able to better comment later after work.

With Ch2 and CH3 in series mode and set to, say, 5v each, place a 100 ohm resistor across CH2 and a 50 ohm resistor across CH3. the current in CH2 should read 50ma and in CH3 should be 100ma. Now set the current limit to 50ma. what is the voltage across ch2 and across ch3? the Voltages should track.

IMG_20240905_073129 - Copy.png => All channels off, V and A set to casual values on CH2 and CH3
IMG_20240905_073140 - Copy.png => CH2 and CH3 set to Series, set to 10V and 1.050A; CH3 is not adjustable at all
IMG_20240905_073203 - Copy.png => 100Ω resistor on CH2 and 50Ω on CH3. CH2 shows total volatge and correct A; CH3 shows channel voltage and correct A. It is not possible to set any value on CH3
IMG_20240905_073409 - Copy.png => lowering current to 0.050A on CH2 produces no effect on either channel as expected
IMG_20240905_074357 - Copy.png => lowering current to 0.045A on CH2 produces lower voltage on CH2 (4.5V) but no change on CH3; CH2 continues to show total voltage
Voltages have been checked with external DMM and their values as shown in the images/reported by me are correct.

dirtcooker is right

[dirtcooker]

Unfortunately I have no time to write down here the results, but I wanted to share asap and hopefully images below are self explanayory.
Will be able to better comment later after work.

With Ch2 and CH3 in series mode and set to, say, 5v each, place a 100 ohm resistor across CH2 and a 50 ohm resistor across CH3. the current in CH2 should read 50ma and in CH3 should be 100ma. Now set the current limit to 50ma. what is the voltage across ch2 and across ch3? the Voltages should track.

IMG_20240905_073129 - Copy.png => All channels off, V and A set to casual values on CH2 and CH3
IMG_20240905_073140 - Copy.png => CH2 and CH3 set to Series, set to 10V and 1.050A; CH3 is not adjustable at all
IMG_20240905_073203 - Copy.png => 100Ω resistor on CH2 and 50Ω on CH3. CH2 shows total volatge and correct A; CH3 shows channel voltage and correct A. It is not possible to set any value on CH3
IMG_20240905_073409 - Copy.png => lowering current to 0.050A on CH2 produces no effect on either channel as expected
IMG_20240905_074357 - Copy.png => lowering current to 0.045A on CH2 produces lower voltage on CH2 (4.5V) but no change on CH3; CH2 continues to show total voltage
Voltages have been checked with external DMM and their values as shown in the images/reported by me are correct.

dirtcooker is right

Thank you Furna. It appears that series mode was intended only to extend the voltage range of the power supply. Siglent really needs to add a dual tracking mode. Possibly they could do it with a firmware change only. It seems a glaring omission to me. Also in your first pic with all outputs off, ch3 reads 1ma. So do I have to add an external multimeter if I want an accurate reading in the low ma ranges? I can do that already with any old plain vanilla power supply I have kicking around. What I'm looking for is a power supply that includes a precision multimeter. That is what Keysight has done and I think Siglent would have been wise to follow their lead.

[hpw]

Just to draw my suggestions again:

- come up with the service manual (after month still missing), to see how to calibrate using the customer mode 

- provide a simple menu as: Copy factory setup to customer mode as to get a nice valid setup to alter 

- colored cables related to current channel colors, otherwise as 4x pairs to follow the cables or even to label

- describe why to provide some current otherwise output shutdown as may the meters requires some small currents

- yes a tracking mode as RIGOL has is a must have 

[Furna]

First of all: never ever takes measurement early in the morning when you just wake up, still didn't drink a coffee, and in a rush to go to work ...

IMG_20240905_074357 - Copy.png => lowering current to 0.045A on CH2 produces lower voltage on CH2 (4.5V) but no change on CH3; CH2 continues to show total voltage

Current was lowered to 0.040A as the image clearly shows.


Let's start with something simple: series mode with dummy load across CH2+ and CH3- ... volatges have been verified with external multimeter (BM869s calibrated in March 2024) at PSU outputs

IMG_20240907_114815.png - the setup; 100Ω resistor measuring 100.34Ω (yes wire wound resistor; this is what I have at the moment for 100Ω).
IMG_20240907_115035.png - series mode 10V and 1.5A set; as expected 0.1A, 10V total with 5V on each channel. I have no idea why CH3 shows 0.101A; also I am not able to reproduce this today.
IMG_20240907_115452.png - voltage reduced to 9V; as expected 0.090A, 9V total and each channel at 4.5V. Still CH3 shows 0.001A more.
IMG_20240907_115810.png - voltage back to 10V, let's start to reduce current to 0.090A to go to CC mode. To get desired current, voltage is reduced only on CH2 but still higher than expected even considering the not exact value of the resisotr; CH3 shows his own correct voltage while CH2 shows the total voltage.
IMG_20240907_120216.png - lowered current to 0.050A ... behaviour confirmed. CH2 almost at 0V with same kind of error as previous image.
IMG_20240907_120335.png - lowered cuurent at 0.040A ... CH2 goes to -0.6V but that is not enough; to have 0.040A we should have CH2 at -1V but pag15 of the manual "The high current channel support remote voltage compensation sense function. The
maximum compensation voltage is 0.6V". Displayed values for CH2 are completely wrong now.
IMG_20240907_120950.png - lowered cuurent at 0.010A ... CH2 goes to -0.7V (contradcting the manual) but it should be -4.0V. Values shown on CH2 are completely wrong. Values shown on CH3 are correct.

I understand this is a corner situation ... every intelligent person would use the independent mode for such low V and A vlaues but definitely the serial mode could be improved in the firmware.

Expecting your comments folks.

[dirtcooker]

Let's start with something simple: series mode with dummy load across CH2+ and CH3- ... volatges have been verified with external multimeter (BM869s calibrated in March 2024) at PSU outputs

IMG_20240907_120335.png - lowered cuurent at 0.040A ... CH2 goes to -0.6V but that is not enough; to have 0.040A we should have CH2 at -1V but pag15 of the manual "The high current channel support remote voltage compensation sense function. The
maximum compensation voltage is 0.6V". Displayed values for CH2 are completely wrong now.
IMG_20240907_120950.png - lowered cuurent at 0.010A ... CH2 goes to -0.7V (contradcting the manual) but it should be -4.0V. Values shown on CH2 are completely wrong. Values shown on CH3 are correct.

It all falls apart at the 40ma setting, when I would expect ch2 to read 4v (total) and ch3 to read 2v. Is 4W sense turned on, or is it greyed out since the manual says it is not supported in series mode? You have found a bug in the series mode with this simple test. Maybe Siglent could supply a schematic so we can help debug their power supply.

[Furna]

It all falls apart at the 40ma setting, when I would expect ch2 to read 4v (total) and ch3 to read 2v.

It seems the strategy (that I do not understand) is to change/lower voltage on CH2 only ... to the point where the firmware authors choose to apply a negative voltage to CH2 instead of lowering CH3 too.

Is 4W sense turned on, or is it greyed out since the manual says it is not supported in series mode?

If 4w is on, you cannot enable parallel/series; if parallel/series is on, you cannot enable 4w.

You have found a bug in the series mode with this simple test. Maybe Siglent could supply a schematic so we can help debug their power supply.

I doubt Siglent will share the schematic ... I hope @tautech will have the chance to signal Siglent the bug(s) we will find.

[tautech]

It all falls apart at the 40ma setting, when I would expect ch2 to read 4v (total) and ch3 to read 2v.

It seems the strategy (that I do not understand) is to change/lower voltage on CH2 only ... to the point where the firmware authors choose to apply a negative voltage to CH2 instead of lowering CH3 too.

Is 4W sense turned on, or is it greyed out since the manual says it is not supported in series mode?

If 4w is on, you cannot enable parallel/series; if parallel/series is on, you cannot enable 4w.

You have found a bug in the series mode with this simple test. Maybe Siglent could supply a schematic so we can help debug their power supply.

I doubt Siglent will share the schematic ... I hope @tautech will have the chance to signal Siglent the bug(s) we will find.

When they arrive myself and Defpom whom is to get one will look carefully at how Series and Parallel modes work. Some weeks away.... 

[Furna]

I doubt Siglent will share the schematic ... I hope @tautech will have the chance to signal Siglent the bug(s) we will find.

When they arrive myself and Defpom whom is to get one will look carefully at how Series and Parallel modes work. Some weeks away.... 

I am sure you guys will have a far better structured approach at testing these PSU; anyway if you need some "work force" to perform a few tests, just let me know.

[mon]

I'm certainly interested what you think of the PSU so far outside of the issues with the channel linking.

[Furna]

I'm certainly interested what you think of the PSU so far outside of the issues with the channel linking.

What I think about the PSU in general ...
When I ordered it, I was conscious it was a bet; there are other issues I currently do not have intention to share yet since I want to leave tautech and Defpom the "exclusivity" of being the first to review the PSU (for sure they are more experienced tah me both as technicians and as reviewers).

The build quality is very good and until now I found the precision pretty accurate and always in spec when measured with BM869s considering also the error margin of this one of wich I have calibration data.
I already mentioned the quality of the included cables; while I was really disapointed at the beginning, I am now getting somehow used but I also have and use a set of alternative cables.
Moreover, cheap for cheap Siglent could have included 4wire sense cables (indeed you need to provide yourself).

The user manual needs a fresh clean up from copy&paste and English mistakes, but it is easily understandable.

All in all I am confident Siglent will release new firmwares and fix the issues and my bet will be a succesfull one ...

BTW did anyone noticed the camera icon just next to Save/Recall button clearly visible in my images?
It is not present in the marketing material and in the user manual too ... but it is there on the real product ... should we expect a new firmaware where you can save the dispaly?

Its a completely different transformer winding I would think.

That's certainly one possibility, but it's not the only possibility. Let's speculate! 😉

See the attached image ...
I didn't take it apart but it might be that the transformer is shared between SPD4121X and SPD4306X

[Furna]

When they arrive myself and Defpom whom is to get one will look carefully at how Series and Parallel modes work. Some weeks away.... 

How many weeks? Any news? What model(s) are you going to receive?

[tautech]

When they arrive myself and Defpom whom is to get one will look carefully at how Series and Parallel modes work. Some weeks away.... 

How many weeks? Any news? What model(s) are you going to receive?

They're on the water so waiting impatiently.......
Top and bottom models are coming, not the middle one at this time.