SPD3303X-E another question regarding binding posts.

[Electroplated]

Hi,

This is regarding my brand spanking new SPD3303X-E that I took deliver of yesterday. A bit of a ramble to start with, My old home built power supply finally gave up the will to live due to a transformer fault, open primary,  it gave stellar service over the years, 0-30V 0-5A, separate 5 and 12V outputs and a 10v AC at 5A. So rather than rewind a new transformer by hand again ( large toroidal and lots of big calculations )  I decided to search for a new one and decided on the SPD3303X-E after reading everything I found about it.

I knew about the binding post problems with early versions and that Siglent have addressed the issue along with the overhearing bridge rec and thought if its anything like the SPD1305X I have then the binding posts wont be an issue, besides the fact the positive and negative terminals are reversed on both models from the same manufacture ( really ? ) however,  none of my banana ended cables fit snug into the SPD3303X-E, the same ones fit snug into every piece of gear I have but on the SPD3303X-E, nope, to get a decent connection I have to use fork terminations or bare wire.

My SPD3303X-E is REV3 with the most recent firmware, not sure what version the binding post issue was fixed, so am wondering if I got an older version ? all I can do is ask call Siglent and speak to them and see where we go from there.

Its a nice supply, does what I need and most important, its fits on my space limited bench, we live in the UK in an old house and I was allowed to have a little bit of space in a spare room, I should have read the marriage license more carefully to see if there is actually a limitation on the maximum allowed hobby area ... its also very quiet.

Besides the gripe about the binding posts not holding banana connectors ( ignoring the 20 mm spacing that I can work around by making new adapters ) the only other bug if it is a bug is the current limiting, it seems rather slow under 50mA, it does go in to current limit mode just as expected but under 50mA its rather slow to respond, under 30mA the warning bleep doesn't work, above 30mA and there's a warning bleep. Maybe Siglent should put a warning bleep on the binding posts to let you know the cables fell out 

Anyway after that Sunday morning ramble, the short version, does anyone know what hardware versions had the binding post problem ?

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[tautech]

5 years ago binding post banana socket issues were resolved when another binding post was fitted however it never resolved users using old and outdated banana plugs.

The list in this post has the perfect examples of this old stuff that should be reserved for instruments of yesteryear that don't prescribe to modern insulation clearances.
https://www.eevblog.com/forum/testgear/siglent-spd3303x-e-binding-post-issues-solved/msg1445242/#msg1445242

So why would I say this ? The modern banana socket has conductive metals deeper in the socket and more insulation length near the opening for just one reason, safety for the user.
Then you ask why, it's a LV PSU ?
Well it is and it isn't, in Series mode these are 60V supplies and you would correctly say that's not exactly dangerous in any way which is true until you take advantage of another feature these units offer.....multiple units can be series'ed together for a max of 500V above mains earth !

Excuse me but in that case I'd prefer any metalwork in the banana sockets to be buried deep within and only reachable with modern quality banana plugs.

[Electroplated]

Thanks for the reply tautech,

Most of mine are either hirschmann or Staubli or Mueller, these are loose when plugged in, easy to wiggle about, they don't leave any exposed metal when pushed in but are loose, these are not cheap rubbish.

Other ones, well some cheap junk that I don't use leave a collar exposed but we don't use those on power supplies, was just comparing junk to decent ones.

There is a huge difference between the binding posts on the SPD3303X-E compared to those on the SPD1305X, besides the obvious differences and fit the SPD3303X-E binding posts do have some play in them against the front panel, the entire binding post assembly can move relative to the front panel, don't have this on anything else.

I'm not going to buy a whole range of test leads in the hope a set will fit when I have a stash of quality ones that I never have issues with, now not sure where to return it or see if other posts can be supplied or fitted, its a shame but in its present state, its not really useable unless you use wires or forks to get a tight connection and that causes a lot more problems than it solves.

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[mawyatt]

Know what you mean regarding the terminals, we have 3 SDP3303. We just don't get a good "feeling" when inserting any banana plug, and they don't seem to engage as deeply as the other instruments. They actually appear more robust and beefier than the terminals on the GPP-4324 we have which are smaller, but work as expected with a deep firm grip.

The electrical performance is quite good and a very good value. Even with the quirky user interface and even with the terminal issues these are our usual "GoTo" supplies when doing quick setups for the lab.

We have all sorts of cables and plugs including the cheap rubbish types, we've found the ones with a long blade type contact rather than the spinning spindle type work better because they have a much longer contact area and will fully engage with the SDP terminals.

Best,

[AVGresponding]

I've an RS-Pro rebranded one, and the terminals are just fine with all my banana plugs, as far as I can see, both cheap and expensive. It has hardware version 3.0

[Electroplated]

Thanks to all those who replied,

I did some more plugging and unplugging this afternoon, it seems the binding posts on mine are odd, on all the negatives, I can literally flick any plug out, one light flick and they pop out, the positives and green ground are loose but can not be flicked out, I will presume my one may be an oddity and hopefully new posts may solve it as I am not to keen to return it, its only those posts, everything else is good, quiet, small footprint a screen can read, however I am not sure if Siglent would send out a set of posts and agree to me changing them rather than have it sent in or exchanged.

As I mentioned, my space is limited as the room is share my family for hobbies, ( you wanna see them run when I blow things up, a blown cap can clear the room for a whole weekend ! ) hence why I decided on the Siglent, besides a few single channel supplies it is the one  out of a few that fit on my shelf, allowing for the cables at the back, next one up in size was an Owon but I believe the fan would drive me insane.

If I cant get the posts changed I may try to make insert slips, if that fails then the only real option would be to duplicate the posts on an extension bar and wire that to the Siglents posts and set the unit further back on the shelf, may look odd but it solves the entire issue.

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[mawyatt]

Send it back, you shouldn't have to put up with that kind of nonsense!! The 3 SDPs we have hold the plugs OK, some not as good but they don't fall out. The plug shown in the image holds very well and sinks deep into the socket.

You must have an older version, because the ones we have the terminals are bad but not to the point where a seated banana plug could just fall out. That's not only aggravating and a nuisance, but also costly if a plug fell out and caused a circuit to fail because of a lost connection to the power supply for example!!

Best,

[Electroplated]

Hi mawyatt,

You made a good point about plugs falling out, my shelf is above the bench, all I need is plug dropping down. I have some of those BUELA 30 K plugs that look similar ( or the same ) as those you posted a picture of, even those are loose and can be easily flicked out, the negative posts are the worst for some reason. Of the 20 odd plugs and leads I have none make a decent connection, so that leads me to wonder about the possibility or arching inside the terminals, its not as if I use junk connectors, I get all mine from RS and they are not cheap ! Even my few BSB 20 K plugs are loose, I dont use them because once stacked they stick out over the shelf.

I'll speak to Siglent UK about this but I don't hold out much hope of getting this resolved without a return, sad really, its a nice supply and fits my needs but given the quality of those posts, nope, I think its put me of Siglent, I mean all that time and money to make a nice unit but they mess up on the terminals and the spacing, even more baffling as the single supply I have has nice solid terminals at the standard spacing !

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[mawyatt]

Just get it exchanged as it's delivered as defective, no need for you to wait or repair.

Contact supplier, get RMA and have them send another "new" unit ASAP, they will charge your account until they receive the returned defective unit, then they will credit your account. The quality distributers here in US work that way, we use Saelig for most of our Siglent equipment. Also Siglent NA is has also been very helpful, they seem to be a quality company that values their customers, even the small ones.

We have a bunch of Siglent stuff, and very happy with most, some has exceptional performance/features for the price.

BTW those plugs shown above, they seat very well and very firm, no way they are going to pull out without a significant tug!!

Good luck.

Best,

[tautech]

I'll speak to Siglent UK about this but I don't hold out much hope of getting this resolved without a return, sad really, its a nice supply and fits my needs but given the quality of those posts, nope, I think its put me of Siglent, I mean all that time and money to make a nice unit but they mess up on the terminals and the spacing, even more baffling as the single supply I have has nice solid terminals at the standard spacing !

Just checked a SPD3303X-E and an older SPD1168X we have here using the supplied banana to croc clip leads.
Did yours come with them ?
Pic below of these and they are quite rigid when inserted.

The way the std supplied banana plugs fit in the X-E is the lantern spring totally clears the outer insulation before it engages with the metal deep in the socket leaving ~7mm before they push fully home.

SPD1168X OTOH has the metalwork much closer to the tip of the terminal due to them not requiring the same degree of insulation as they are not rated for series operation like SPD3303X and X-E are.
This SPD3303X-E unit is late 2021 production with a SN# SPD3XIDX5R****

What range of SN# is yours Electroplated ?

I also have some reasonable quality stackable retractable shroud banana leads that work perfectly well however their lantern spring is of a different design and only some 8mm long with its center swelling nearer the plug tip. These engaged with the metalwork only permit a further 5mm of engagement yet are quite firm enough when fully inserted.

I'm getting a feeling yours may be an old unit, maybe some old stock from somewhere in the EU system as what you describe doesn't mirror our tests today but your SN# should tell us what's really going on.

[Electroplated]

Morning mawyatt,

Wish my plugs that look similar needed a significant tug, well they do on the single Siglent and on some junk psu that I use for my hobby drill and water pump and they are as tight as a nats wotsit when plugged into my home brew psu !

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[Electroplated]

Morning tautech,

The serial on my SPD3303X-E is SPD3XIEC6R0xxx, hardware version 3. the only other thing I noticed is if I look through the sides with a light the mains switch harness appears to be tied up as it seems to loop down into the switch pcb.

Mine was supplied with a set of plug leads that fit, but are still easy to pull out, again its the negative terminals that seem worst effected with channel one being the worst with a lot of play, wiggle wiggle and its out, as for the plug, that as well  , if I plug those supplied leads in to anything with a binding post, they fit tight, fit into  HIRSCHMANN binding posts and they are hard to pull out, so the supplied ones seem fine to me.

I don't have retractable ones that would fit because not enough pin is exposed to get to the magic 20mm, worked that out by reading other posts here and measuring what I have. I did originally think my testing was flawed because some of the leads had wear but I have some unused BUELA 30 K that are still loose, I don't use them as they are blue and yellow, I use red, black and green on power supplies to stop my feeble aging mind becoming confused 

Just a quick edit to my reply, I've taken on board what you say about the binding posts being different due to the SPD3303X-E being used in serial or parallel mode, probably a similar reason to why the spacing is different to prevent using those infernal twin plug type adapters, especially the junk bnc type.

The only other thing to note is mine never had the peel off screen sticker on it but not sure if they are fitted or it was removed during a pre-delivery check, on the other hand, I've been using a Siglent scope for 6 years and only removed the screen sticker last week and spent ages removing the sticky that was left behind, one of those things I kept meaning to do but never did until the screen seemed dim :-)

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[tautech]

Morning tautech,

The serial on my SPD3303X-E is SPD3XIEC6R0xxx, hardware version 3. the only other thing I noticed is if I look through the sides with a light the mains switch harness appears to be tied up as it seems to loop down into the switch pcb.

Mine was supplied with a set of plug leads that fit, but are still easy to pull out, again its the negative terminals that seem worst effected with channel one being the worst with a lot of play, wiggle wiggle and its out, as for the plug, that as well  , if I plug those supplied leads in to anything with a binding post, they fit tight, fit into  HIRSCHMANN binding posts and they are hard to pull out, so the supplied ones seem fine to me.

Evening EP. 

Ok you certainly have an issue with those banana sockets as they should hold any modern plug just fine so yes, as mawyatt says it needs go back as it's not fit for purpose.

The only other thing to note is mine never had the peel off screen sticker on it but not sure if they are fitted or it was removed during a pre-delivery check, on the other hand, I've been using a Siglent scope for 6 years and only removed the screen sticker last week and spent ages removing the sticky that was left behind, one of those things I kept meaning to do but never did until the screen seemed dim  :-)

Only the latest touch display Siglent devices come with protector overlays these days but there is the odd exception like the latest SHS series.

[Electroplated]

Hi tautec,

Nice to know the overlays are not fitted these days, bit less plastic to dispose of !

I'm going to squeak, I mean speak to Siglent or its handling company in a hour or so, thing is both websites state I should pay return carriage for under warranty repairs so I may need to bitch about that if it needs to go back, by nature I am a tight wad,  if given a preference I would try new posts and fit them myself as it saves a lot of faffing about, getting Siglent to agree may be not easy, I understand why they may refuse that but can only ask.

All that said, I found a use for the timer, never used a time but I designed a simple toggle switch that controls a relay, I wanted to test the thing with rapid on/ off cycles, did the job 

Will post later about how I get on, thanks for all the information and testing the plugs I saw in the pictures, very much appreciated.

Another quick edit, spoke to the handling company for Siglent UK and am waiting for Siglent to respond to them, I mentioned swapping the posts but we will see, don't matter what they decide, I'll end up with one of these either way.

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[tautech]

I'm very interested in the outcome as we get a new shipment of these PSU's in the next week or 2 after not having had any for a while and if they have loose banana plug sockets.......I won't be pleased.

[rf-loop]

If the original genuine Hirschmann BUELA 30K is indeed too loose, there is something seriously wrong with the binding post. BUELA 30K (also 20K) is just the right plug for these connectors.
Note: There are also many more or even total shit " look-alike " copies of "Hirschmann BUELA 30K". (for example, the spring force may be very weak due to wrong material and the spring prongs are too soft, which means that they lose spring force very quickly in use.)

Could you measure the inside diameter of the hole in the power supply connector - exactly?
For some reason I value real raw data more than opinions and feels.

We know what it should be. As far as I understand, there are also defined tolerances for it. After all, Hirschmann is the original developer of that whole banana plug from the beginning of the last century. If these are not ok for these binding posts - then binding post are wrong.
It's really unbelievable that this could be an issue in 2022.
Example: CalTest gives the dimensions of the internal contact hole of the banana plug: Ø .157 ± .002 (Ø 4 mm ± .05 mm)
I have somewhere old design drawing about these Siglent binding posts but I do not remember dimensions and tolerances. And can not find this image now.

[Electroplated]

Hi rf-loop,

I've used digital needle calipers that go to the metal inserts I get these measurements, best I could do and should have done this sooner ! ( measurement method: zero calipers, insert across plastic outer casing, take a measurement, rotate calipers 90 degrees, take measurements)

reading  left to right:

Neg ch1   4.90 mm
Pos ch1   4.70mm
Gnd         4.77mm
Neg ch2  4.82mm
Pos ch2  4.86mm
Neg ch3 4.85mm
Pos ch3  4.83mm

Inserting the calipers into the metal receptacle I get:

reading  left to right:

Neg ch1   4.48 mm
Pos ch1   4.42mm
Gnd         4.37mm
Neg ch2  4.47mm
Pos ch2  4.43mm
Neg ch3 4.47mm
Pos ch3  4.43mm

As a comparison:

Staubli 23.0330-22 red binging post, new unused for a test, inside metal receptacle : 3.99mm
Second measurement resulted in 4.08mm so there is some error in my measurements but not much compared to its RS data sheet.

Still not heard back from Telonic or Siglent yet.

[Electroplated]

I'm very interested in the outcome as we get a new shipment of these PSU's in the next week or 2 after not having had any for a while and if they have loose banana plug sockets.......I won't be pleased.

Hopefully mines just a oddball, it can happen so lets see before those negative waves begin to cause some gloom 

Not heard anything back yet, probably a bit too soon to expect a response, Tommorow I wont be here till tomorrow night, if at all, hospital job, the bone pullers want my remaining few teef so I can fitted with someone else's so I get my Mr Ed look back, may have to change my forum name to something suitable, like toothless wonder or ol stumpy....

Rest assured, once I hear something I will let you know but I bet I have a Friday job SPD3303X-E, unless they had issues with sourcing parts due to the state of the world and dug out that big box of posts they had to change.......and I got one 

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[mawyatt]

Couple things I do like about these terminals are they seem to be beefy and really like the colored tips.

The colored tips make it very easy to see from anywhere at any angle, even with plugs engaged, while the GPP-4323 only has thin colored washers behind the the smaller terminals. This makes it very difficult to see from anywhere, we are always having to take multiple "looks" just to be sure of what terminal is what, however the plug fits securely with any plug!!

Best,

[Electroplated]

I think the best thing is the spacing, that little bit more so fat fingers can tighten the terminals, I sometimes struggle on the standard 19cm spacing, more so if the knurling / grip isn't so good or like me a bit of arthritis affects the fingers, I would rather have the extra distance, something I have never really thought about till I got this bench supply.

Your point about the big colour rings is a good one, yes they much easier to see, I have a old power supply that lost its lettering, the posts have a thin line of color around the end, you cant see it if a plugs in place unless you pull it back a little, its a pain in the backside doing that, luckily I don't use it that often, its mostly used to drive a 12v water pump that's used to rapidly empty water butts and a small fountain, takes too long for gravity to do it and I would rather do something else than babysit buckets, unless they are full of a decent home brew 

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[mawyatt]

Here's the GPP-4323 terminals (left) and SDP3303X terminals (mid).

Judge for yourself!

Best

[jjoonathan]

I'm a big fan of colored rings too -- I even added some to my GPP4323 and made a video about it!

https://youtu.be/RkpahjgQoiA?t=44

[mawyatt]

Nice idea with the markers!! Did you coat the terminals with clear coat?

For the probe clips why not use heat shrink tubing, it comes in most colors?

Best,

[jjoonathan]

Yep, I put top coat on the terminals too. It hasn't cracked yet, despite many plug/unplug cycles and direct contact between two surfaces with paint + top coat.

Heat shrink tubing is great -- if you can get it where you want it. Sloped, slippery surfaces are tricky and the finite contraction ratio is sometimes a challenge too. Acrylic paint is more versatile, though I suppose it wouldn't work on flexible substrates. Nature abhors a silver bullet 

[Electroplated]

mawyatt,

Nice picture, it just confirms you collect binding posts and the PSU attached to them is the price collectors pay