Is there a better power supply option for $700?

[JJ_023]

I am looking primarily for something new not used off of eBay.

I know that this statement was written in bold, but I would urge you to reconsider. High quality used power supplies are fairly abundant in the USA.

I have honestly tried that route.  Either I don't feel comfortable about the device or it's in such bad shape that cosmetically it would irk me.  I know it's silly coming from a guy who would sharpie red and black on the outputs of a brand-new unit. 

Maybe I am just not good sourcing used stuff but every time I look on eBay anything decent is maybe $200 cheaper than buying it brand-new.  If I could get that unit $150 in good shape I would gladly risk it.  But I never come across those types of deals.  I also don't spend hours every day looking for a good deal to pop up so that's probably the reason why. 

[JJ_023]

One thing is that you do need proper lab psu.  More than one, isolated from each other.
Other thing is what kind.
You won't need network connected smart PSU most of the time.
Most of the time simple analog one with potentiometers is good enough.
You can have several single channel ones instead of one multi channel.
You want a smart one with LAN and SCPI only if you want to write scripts to automate it.

Also some multi channel PSU have weird channel combinations. Instek GPP-4323 has 2 channels with full capacity but 15V and 5 V have only 1 A capacity. Some will argue that it would be more useful to have 3 full capability channels instead..

It all depends on your needs.

Thank you for chiming in, all of these are very valid points.  Seems like you always need more than 1 of everything when it comes to serious things.  I thought about getting several single power supplies.  I think I would easily exceed the $700 mark if I bought 3 that had similar specifications to the one I am considering or the Rigol. 

[tautech]

Although we don’t yet have a release date, this might be of interest if you’re not in a hurry:
https://www.eevblog.com/forum/testgear/new-siglent-spd4000x-series-power-supply/

[JJ_023]

Although we don’t yet have a release date, this might be of interest if you’re not in a hurry:
https://www.eevblog.com/forum/testgear/new-siglent-spd4000x-series-power-supply/

It looks like it might be interesting for sure.  I am not in a hurry however who knows when this might come out.  I guess if the timing is right I would love to consider it.  What is the price of this unit from the latest rumor mill?

On a different note I asked you at one point in a previous post about possibly paralleling or in series several Siglent power supplies together.  You said you would check with the company and get back on some of the technical details if it's possible.  Did you by any chance find anything out?

[tautech]

Although we don’t yet have a release date, this might be of interest if you’re not in a hurry:
https://www.eevblog.com/forum/testgear/new-siglent-spd4000x-series-power-supply/

It looks like it might be interesting for sure.  I am not in a hurry however who knows when this might come out.  I guess if the timing is right I would love to consider it.  What is the price of this unit from the latest rumor mill?

On a different note I asked you at one point in a previous post about possibly paralleling or in series several Siglent power supplies together.  You said you would check with the company and get back on some of the technical details if it's possible.  Did you by any chance find anything out?

Oh you can be sure I’ve enquired about SPD4kX however Siglent aren’t ready to share anything about it yet. 

Series mode with multiple units is no problem up to the max of 500V above mains ground but offhand I can’t offer any info about Parallel mode with multiple units.
Sorry on hols for another couple weeks.

[JJ_023]

Although we don’t yet have a release date, this might be of interest if you’re not in a hurry:
https://www.eevblog.com/forum/testgear/new-siglent-spd4000x-series-power-supply/

It looks like it might be interesting for sure.  I am not in a hurry however who knows when this might come out.  I guess if the timing is right I would love to consider it.  What is the price of this unit from the latest rumor mill?

On a different note I asked you at one point in a previous post about possibly paralleling or in series several Siglent power supplies together.  You said you would check with the company and get back on some of the technical details if it's possible.  Did you by any chance find anything out?

Oh you can be sure I’ve enquired about SPD4kX however Siglent aren’t ready to share anything about it yet. 

Series mode with multiple units is no problem up to the max of 500V above mains ground but offhand I can’t offer any info about Parallel mode with multiple units.
Sorry on hols for another couple weeks.

Thank you for making the effort.  Enjoy your holiday. 

[Antonio90]

 

I have a GW Instek, a GPD-4303S. It works quite well as a psu, reasonably precise, stable, and reliable OCP and OVP, but cannot show the settings of more than two channels at once on the screen, and you have to turn on/of all channels at once. This last flaw is, by far, the worst.

If I were to buy another PSU right now, it would probably be the one you are considering. There is custom firmware in this forum for the GPP, which improves readback speed, and accuracy? Can't recall right now.

I would have a look at AIM-TTI supplies. They are also really precise, with sense terminals on the front, and simple interfaces. More expensive for the same features, and I don't think you will get two quadrant supplies for that budget outside of the GPP. The MX series from TTI look quite nice though.

Thank you for taking the time to respond.  Not being able to show more than 2 channels at the same time might be a nuisance in certain occasions I don't particularly see that as that big of a nuisance.  Can you control this on a PC screen?

If I understand you correctly that is a big PITA.  I see 4 buttons for channels.  What are they for if you can't turn them on and off independently? 

I don't necessarily need the 4 channels but it is an appealing feature.  I am not familiar with that particular brand I will have to do a little bit of research.  Do you have a specific model you would recommend without getting into a different price bracket?

The buttons are for selecting which channel is receiving input from the adjustment knobs. About the screen showing only two channels, yeah, it is not too big of a deal, as there is a (rather simple) computer interface. This is all for the GPD I have, the GPP you are considering doesn't have any of those problems. The numbers are not as easy to read though.

I was looking at the  PL303QMD. But just saw in the datasheet that it has no computer interfaces unles you pick the -P version which is much more expensive. The QL355T is already quite a bit more expensive without interfaces.

I don't think there is a better option from TTI at that price bracket, my apologies.

[flano]

Thank you for the data point.  What is something that you don't like about the Rigol?  I've considered that unit as well.

Nothing really. It only has 3 channels vs 4 for the GPP-4323, but that's not an issue for me. GPP-4323 also has an electronic load.

The Rigol does everything I need, very happy.

Mike VK4MWL

[nctnico]

Thank you for the data point.  What is something that you don't like about the Rigol?  I've considered that unit as well.

Nothing really. It only has 3 channels vs 4 for the GPP-4323, but that's not an issue for me. GPP-4323 also has an electronic load.

The Rigol does everything I need, very happy.

IIRC the Rigol 930 series does not have seperate grounds for all channels. This could be problematic in some situations.

[2N3055]

Thank you for the data point.  What is something that you don't like about the Rigol?  I've considered that unit as well.

Nothing really. It only has 3 channels vs 4 for the GPP-4323, but that's not an issue for me. GPP-4323 also has an electronic load.

The Rigol does everything I need, very happy.

IIRC the Rigol 930 series does not have seperate grounds for all channels. This could be problematic in some situations.

900 series actually has all 3 ch isolated. It is DP83x that does not isolate ...

[2N3055]

Battery charging should be left to battery chargers. Battery chargers are cheap and common.

[Pfriemler]

looking forward to buy a PSU, I got stuck on the GWs with load function as well. As a benefit to a well constructed and basically reliable PSU it‘s nice to have an EL, but I really love my Kunkin KP184 as a separate device, not only because it can handle up to 400 watts and 150 volts. Before that, I used some Chinese naked PCBs with fans on it up to 50 watts. I am very glad to leave them behind.
Rigol? did not the 83x series have many odd issues in behaviour and stability?

[JJ_023]

I have a GW Instek, a GPD-4303S. It works quite well as a psu, reasonably precise, stable, and reliable OCP and OVP, but cannot show the settings of more than two channels at once on the screen, and you have to turn on/of all channels at once. This last flaw is, by far, the worst.

If I were to buy another PSU right now, it would probably be the one you are considering. There is custom firmware in this forum for the GPP, which improves readback speed, and accuracy? Can't recall right now.

I would have a look at AIM-TTI supplies. They are also really precise, with sense terminals on the front, and simple interfaces. More expensive for the same features, and I don't think you will get two quadrant supplies for that budget outside of the GPP. The MX series from TTI look quite nice though.

Thank you for taking the time to respond.  Not being able to show more than 2 channels at the same time might be a nuisance in certain occasions I don't particularly see that as that big of a nuisance.  Can you control this on a PC screen?

If I understand you correctly that is a big PITA.  I see 4 buttons for channels.  What are they for if you can't turn them on and off independently? 

I don't necessarily need the 4 channels but it is an appealing feature.  I am not familiar with that particular brand I will have to do a little bit of research.  Do you have a specific model you would recommend without getting into a different price bracket?

The buttons are for selecting which channel is receiving input from the adjustment knobs. About the screen showing only two channels, yeah, it is not too big of a deal, as there is a (rather simple) computer interface. This is all for the GPD I have, the GPP you are considering doesn't have any of those problems. The numbers are not as easy to read though.

I was looking at the  PL303QMD. But just saw in the datasheet that it has no computer interfaces unles you pick the -P version which is much more expensive. The QL355T is already quite a bit more expensive without interfaces.

I don't think there is a better option from TTI at that price bracket, my apologies.

Thank you for the additional information.  I looked at both of the models that you referenced.  What makes you think any of those are better choices.  They just seem more expensive.  I am no power supply expert, so I am trying to figure out what I am missing from your suggestions.

[JJ_023]

Thank you for the data point.  What is something that you don't like about the Rigol?  I've considered that unit as well.

Nothing really. It only has 3 channels vs 4 for the GPP-4323, but that's not an issue for me. GPP-4323 also has an electronic load.

The Rigol does everything I need, very happy.

IIRC the Rigol 930 series does not have seperate grounds for all channels. This could be problematic in some situations.

Could you please give me a few examples as a data point where that would be problematic?

[JJ_023]

Battery charging should be left to battery chargers. Battery chargers are cheap and common.

That is a very valid point.  I still sometimes like to use a power supply to charge batteries especially 18650s above 1A.  I also deal with odd size lithium batteries so sometimes it's a lot easier for me to custom fabricate a holder then have numerous specialty chargers.  It's just a preference, probably not a good one.

[JJ_023]

looking forward to buy a PSU, I got stuck on the GWs with load function as well. As a benefit to a well constructed and basically reliable PSU it‘s nice to have an EL, but I really love my Kunkin KP184 as a separate device, not only because it can handle up to 400 watts and 150 volts. Before that, I used some Chinese naked PCBs with fans on it up to 50 watts. I am very glad to leave them behind.
Rigol? did not the 83x series have many odd issues in behaviour and stability?

Having an electronic load inside a power supply is nice but no way a needed feature for me.  I have a decent amount of experience with all sorts of industrial machines.  The reason I say that is usually combination units compromise on 1 of the combinations.  So I don't really expect much from that particular load.  I do however expect a good power supply as its main role.  I think primarily I would limit it to stupid stuff like discharge curves of a battery at a low current.

I have no idea on the Rigol.

[ArcticGeek]

Thank you for the data point.  What is something that you don't like about the Rigol?  I've considered that unit as well.

Nothing really. It only has 3 channels vs 4 for the GPP-4323, but that's not an issue for me. GPP-4323 also has an electronic load.

The Rigol does everything I need, very happy.

IIRC the Rigol 930 series does not have seperate grounds for all channels. This could be problematic in some situations.

Just to be clear, the DP932 series has all of the channels floating relative to the other channels.  This was NOT the case with the DP832 series from Rigol, however.

[ArcticGeek]

@JJ_023

The GPP-4323 is a decent supply but it does have its drawbacks.  For these reasons I recently sold mine after about a year and got a different unit.

The things I am referring to might seem petty, but I found them very annoying.  The things I don't like about the GPP-4323 are:

1.  The screen is really too small for display all 4 channels at once.  If you have it directly in front of you, its okay.  But I have my power supply on the shelf above my bench, and I find it very difficult to read all of the settings for all of the channels because the font is so small.  I actually sent an email to GW-Instek requesting a FW update that made the font a bit larger and possibly removed other things in the window such as OVP and OCP....and they basically were not interested.

2.  The layout of the binding posts on the front panel is very ackward for me to get used to.  From a very early age I learned to read from left to right and that you count 1,2,3,4 in that order.  Instek decided on this goofy arrangement of Channel 4-1-2-3 on the front panel makes sense.  I could never get used to this and it was always confusing.

3.  Related to #2 above, the screen which shows each channel's status is shown as channel 1 and 2 on the top, and channels 4 and 3 on the bottom (in that order).  Again, I find this very annoying because I'm accustomed to counting 1-2-3-4 (reading from left to right).

4.  The binding posts are not really color coded and marked very well.  Most mfgrs put a red ring around the positive and black ring on the negative binding post at the end of the binding post.  Instek only has the small red and black band BEHIND the binding posts, and I found myself spending way too much time just to make sure I have the right polarity and connected to the right set of binding posts.

As others have mentioned, this unit has good specs and built well, but these user interface issues mentioned above became a real problem for me.  If you don't think these issues would bother you, this unit is pretty good.

In case you are wondering, I purchased a Rigol DP932E as a replacement for the Instek unit, and added the $100 high-res option (although I think that is hackable now).  Although it's only 3 channel, I find that the user interface is much more friendly than the Instek and it's much easier/quicker to connect my leads and read the current/voltage of all the channels.

Just my opinion for what its worth.  Good luck in your decision.

Thank you for such an elaborate response.  When it comes to personal preferences I don't think anything is petty.

1.  I can't really comment on the screen size because I haven't seen this particular unit in person.  Usually that sort of stuff won't bother me as much.  I think you can run it off the PC.  Is this not the case? 

I'm also surprised that some of the talented people on this forum that have this particular supply have not figured out a way to adjust the font size.

2.  I agree that is a pretty stupid way of doing it.

3.  This is also pretty stupid, I totally agree.  Do they issue firmware updates? If so how often?

4.  This also doesn't make much sense however I would probably solve that with a sharpie.  Don't laugh.

I have thought about the Rigol seems like a decent unit.    Is there anything about the Rigol that you don't like and bothers you as well?  Why is the DP932E 195W and the DP932A 210W.  I thought it is basically the same unit that's why it is upgradable.

The DP932E is only rated for 30V/3A and the DP932A is rated 32V/3A.  I think in both cases the max current is 3.2A on the actual unit, and as I recall I think the max voltage that you can set on my DP932E is 31.5V.

There are 2 things I don't like on the Rigol DP932E:

1. The fan control.  When you first turn it on it's at the max setting and quiets down once booted.  Even at the slowest speed it's still a little annoying, although from what I understand it is still better than the older DP832.  I've found from experimenting that the fan algorithm is pretty simplistic - if you short all 3 outputs when set at max current the fan stays at the lowest speed for 3 minutes and then goes to max speed, no matter how warm/hot things were previously.  Once the outputs are no longer at max current the fan immediately goes back to the lower speed. 

2.  When you press the ALL ON/OFF button you are prompted "Are you sure you want to turn all outputs on?" and you have to either press enter or select to get the outputs to turn on.  This requires a second button press, and I find it very annoying. 

I sent an email to Rigol asking for a change to this as well and the fan issue , and their response was that they might consider a change to the ALL ON button action in a future FW release if other customers requested it as well.  They did not make any comments about the fan.

I continue to hope that they improved both issues in future FW changes.

[JJ_023]

The DP932E is only rated for 30V/3A and the DP932A is rated 32V/3A.  I think in both cases the max current is 3.2A on the actual unit, and as I recall I think the max voltage that you can set on my DP932E is 31.5V.

There are 2 things I don't like on the Rigol DP932E:

1. The fan control.  When you first turn it on it's at the max setting and quiets down once booted.  Even at the slowest speed it's still a little annoying, although from what I understand it is still better than the older DP832.  I've found from experimenting that the fan algorithm is pretty simplistic - if you short all 3 outputs when set at max current the fan stays at the lowest speed for 3 minutes and then goes to max speed, no matter how warm/hot things were previously.  Once the outputs are no longer at max current the fan immediately goes back to the lower speed. 

2.  When you press the ALL ON/OFF button you are prompted "Are you sure you want to turn all outputs on?" and you have to either press enter or select to get the outputs to turn on.  This requires a second button press, and I find it very annoying. 

I sent an email to Rigol asking for a change to this as well and the fan issue , and their response was that they might consider a change to the ALL ON button action in a future FW release if other customers requested it as well.  They did not make any comments about the fan.

I continue to hope that they improved both issues in future FW changes.

I see the difference.  I was originally under the impression that they were the same unit and it's just a matter of different firmware.  I guess I stand corrected.

I am not 1 of these people that is bothered by fan noise.  I am surprised at how many people are distracted by this. 

The ALL ON button might be a pain but in other cases it might save you.  Can you individually turn channels on and off?

It would be nice if companies actually listened to people that spend money on their products. lol

Again thank you for the information and your time.

[nctnico]

I am not 1 of these people that is bothered by fan noise.  I am surprised at how many people are distracted by this. 

Wait until you get a bit older. Fan noise will become a nuisance. It is easier to concentrate on a difficult problem in a quiet environment.

[Smokey]

...it's very responsive on the communication ports....

I looked through the documents and I didn't see a spec for communication speed/update rate.  Do you know what the actual spec is for this on the GPP-4323?

(My quest for bench supply -> poor mans SMU continues.....  This actually ticks a lot of boxes if it has source/sink and a fast update)

For reference, this was my thread about Rigol command processing time.
https://www.eevblog.com/forum/testgear/rigol-dp832-remote-command-update-rate/

[JJ_023]

I am not 1 of these people that is bothered by fan noise.  I am surprised at how many people are distracted by this. 

Wait until you get a bit older. Fan noise will become a nuisance. It is easier to concentrate on a difficult problem in a quiet environment.

I get what you are saying.  Certain noises definitely bother me.  But what's funny is I sometimes use a loud fan to drown out the noises that do bother me when I need to concentrate on certain documents for equations.  It also helps me sleep. 

[JJ_023]

...it's very responsive on the communication ports....

I looked through the documents and I didn't see a spec for communication speed/update rate.  Do you know what the actual spec is for this on the GPP-4323?

(My quest for bench supply -> poor mans SMU continues.....  This actually ticks a lot of boxes if it has source/sink and a fast update)

For reference, this was my thread about Rigol command processing time.
https://www.eevblog.com/forum/testgear/rigol-dp832-remote-command-update-rate/

All I remember is that it had a 115200 transmission baud rate via USB.  That's from the manual not the datasheet.

[Smokey]

What I'm interested in are the command processing time and the minimum dwell time for remote commands.  But then again I'm a crazy person so none of this should really impact your decision unless you are also the same type of crazy.

[JJ_023]

What I'm interested in are the command processing time and the minimum dwell time for remote commands.  But then again I'm a crazy person so none of this should really impact your decision unless you are also the same type of crazy.

Right now I don't really have any of those needs but who knows down the road I might lose my sanity and have the same exact type of need.