Choosing a PSU, what should I look for

[Mr. Scram]

Do I really have to point out that I'm not the only one here who has used gear? Thousands of people buy used gear and for most it works out just fine. Older higher end equipment tends to be very well made.

I was talking about your experience with a Chinese unit, not even taking things like confirmation bias into account.

[rstofer]

Thank you. I want my computer as far as possible from my bench so I don't know about the computer controllable one. Also I just need a PSU, I wouldn't know how to use the graphing or anything.

Cheers

But...  A lot of hobby level electronics revolves around Arduinos and other microcontrollers.  Personally, I like to play with FPGAs.  More important is the Digilent Analog Discovery 2 - you should really check it out.  You get a lot of test equipment in a pocket sized box but, yes, it needs a computer.  It's a terrific tool!

I can't imagine not having a computer along side my work area (I'm deliberately not calling it a bench).  I have a table top fully around 3 sides of a bedroom/hobby room.  In the center of the U is where I play with electronics.  The rest of the tabletop is relegated to computers, printers and assorted networking stuff.  Lots of computers...

I guess if I were doing audio I might not need a computer unless I wanted to measure THD with the Analog Discovery.  Or maybe if I was interested in the phase response and gain (versus frequency, of course) of some amp but I don't do audio...

Every development board I buy has a USB programming port.  If it didn't, I wouldn't buy it!

[Moriambar]

Thank you. I want my computer as far as possible from my bench so I don't know about the computer controllable one. Also I just need a PSU, I wouldn't know how to use the graphing or anything.

Cheers

But...  A lot of hobby level electronics revolves around Arduinos and other microcontrollers.  Personally, I like to play with FPGAs.  More important is the Digilent Analog Discovery 2 - you should really check it out.  You get a lot of test equipment in a pocket sized box but, yes, it needs a computer.  It's a terrific tool!

I can't imagine not having a computer along side my work area (I'm deliberately not calling it a bench).  I have a table top fully around 3 sides of a bedroom/hobby room.  In the center of the U is where I play with electronics.  The rest of the tabletop is relegated to computers, printers and assorted networking stuff.  Lots of computers...

I guess if I were doing audio I might not need a computer unless I wanted to measure THD with the Analog Discovery.  Or maybe if I was interested in the phase response and gain (versus frequency, of course) of some amp but I don't do audio...

Every development board I buy has a USB programming port.  If it didn't, I wouldn't buy it!

When I use micros I program them far from the "bench". My old computer got stolen from me and had to buy a new one this year and I'm too scared of that blowing up to keeping it near. So it's "no way José". That's also why I invested in the SDS1104x-e oscilloscope: its logic decoding is fantastic. I really love dedicated instrumentation such as scopes and such and I really hate pc-based stuff such as logic analyzers. Granted: they're needed sometimes, but the 10$ cheap chinese one I have is already overkill for me. And when I have to use it boy am I scared to bring my precious laptop nearby hahah.



To summarize: computer-> as far from the bench as possible. Both because I'm not confident enough and because I do hate pc-driven instrumentation. Perhaps one day I'll buy a cheap ass computer and put it on the bench and if it blows up who cares. But not now!

EDIT: please do mind that mine are a beginner needs, and that I practically do not know how to use a bjt (since I use mosfets as switches and never needed a transistor for anything else!)

[rdl]

I was only pointing out the worst issue (to me) of the two power supplies. Maybe Siglent did fix the rust problem. The EEVblog 828 teardown of the SPD3303X does show the problem still in December of 2015, but maybe that was old stock. At least the Siglent power supply does look much better than the Rigol, though I'm not too fond of the colors.

[Mr. Scram]

I'll stick firmly to what I have posted and still call you unread.....or just too damn lazy to hunt out the appropriate threads, quotes and posts. 

Catch up time, the most recent of this below is 3+ years old.
Start here:

And:

And:

And:

Post by EEVblog:

Yes, they changed their process and fixed it.
They were very poor at communicating this though.

You don't seem to understand how harmful your behaviour is for the image of the brand. If you want to look like a chancy Chinese outfit, shooting and insulting the messengers, downplaying the issue and saying it's not the fault of the brand is the way to do it. Flat out denial and unpleasantness aren't going to win you customers. Proper brands own up to their mistakes and don't attempt to insult anyone who mentions them. Daniel Bogdanoff won't be seen doing whatever it is you're doing on here.

I did read up on the issue and found Dave was offered a second review unit, but he wasn't interested in that since he just caught Siglent employees making sock puppet accounts on here. The only large outfit to ever be caught at that point and as far as I'm aware it still is.

They fixed it.
They offered me a unit to inspect to follow-up but this was at the same time as Siglent employees were caught creating dummy accounts on the forum, so I had no interest in it after that.

[rstofer]

When I use micros I program them far from the "bench". My old computer got stolen from me and had to buy a new one this year and I'm too scared of that blowing up to keeping it near. So it's "no way José".

To summarize: computer-> as far from the bench as possible. Both because I'm not confident enough and because I do hate pc-driven instrumentation. Perhaps one day I'll buy a cheap ass computer and put it on the bench and if it blows up who cares. But not now!

I worry about it too!  I primarily use a high end model of the Surface Book.  I forget what it cost but it was a bunch!  A replacement at Best Buy today is $2900 plus tax so about $3200 out the door (plus the extended warranty for another $279 give or take).  So, I have a powered USB hub for driving my projects.  On the way by, I get 3 charging ports...

https://www.amazon.com/gp/product/B00VDVCQ84

You can also buy USB isolators and I have a couple but haven't played with them.  One problem with the whole electronics thing versus PCs is the fact that we use external supplies.  We have a source of power that didn't start with the USB port.  Most of my projects do, in fact, use the power from the USB port.  In a lot of ways, this is safer than combining USB and wall wart power on the same board.  Those boards that have this feature vary widely in how they protect the USB port.

Here is one way to power a breadboard from USB and keep everything on the same power source, Power Bricks:

https://store.digilentinc.com/powerbricks-breadboardable-dual-output-usb-power-supplies/

As with anything, there are limitations.  I have a complete set but I haven't been doing any breadboarding.  I'll see how it turns out...

I wish they made a +-15V brick for op amp projects!  12V might be enough with modern op amps but not with the older models and a +-10V signal swing.

I don't know of any good way to get a decent Bode' Plot from anything less than a full blown network analyzer without using something like the Analog Discovery 2.  I really want a log scale for frequency and I really want the Y axis scaled in dB and degrees and while there are some dubious workarounds on a scope, they aren't Bode' Plots when they're done.

When you want to discuss impedance with your grandson, it's nice to be able to show the Bode' Plot and discuss the break points and roll-off rates with diagrams that are properly scaled and annotated.  Even an ME student is going to have to take a course in Circuits.  Yes, I'm an evangelist for the AD2.

[Moriambar]

I worry about it too!  I primarily use a high end model of the Surface Book.  I forget what it cost but it was a bunch!  A replacement at Best Buy today is $2900 plus tax so about $3200 out the door (plus the extended warranty for another $279 give or take).  So, I have a powered USB hub for driving my projects.  On the way by, I get 3 charging ports...

https://www.amazon.com/gp/product/B00VDVCQ84

You can also buy USB isolators and I have a couple but haven't played with them.  One problem with the whole electronics thing versus PCs is the fact that we use external supplies.  We have a source of power that didn't start with the USB port.  Most of my projects do, in fact, use the power from the USB port.  In a lot of ways, this is safer than combining USB and wall wart power on the same board.  Those boards that have this feature vary widely in how they protect the USB port.

Here is one way to power a breadboard from USB and keep everything on the same power source, Power Bricks:

https://store.digilentinc.com/powerbricks-breadboardable-dual-output-usb-power-supplies/

As with anything, there are limitations.  I have a complete set but I haven't been doing any breadboarding.  I'll see how it turns out...

I wish they made a +-15V brick for op amp projects!  12V might be enough with modern op amps but not with the older models and a +-10V signal swing.

Thanks for the info, the power bricks surely look rather interesting. I will look to the rest too.

I don't know of any good way to get a decent Bode' Plot from anything less than a full blown network analyzer without using something like the Analog Discovery 2.  I really want a log scale for frequency and I really want the Y axis scaled in dB and degrees and while there are some dubious workarounds on a scope, they aren't Bode' Plots when they're done.

When you want to discuss impedance with your grandson, it's nice to be able to show the Bode' Plot and discuss the break points and roll-off rates with diagrams that are properly scaled and annotated.  Even an ME student is going to have to take a course in Circuits.  Yes, I'm an evangelist for the AD2.

Never had the need of a bode plot actually. I only did a bit around 20 years ago or so in one uni lab, but never again. I repeat: I do basically only digital stuff. Program the arduino and then remove the pc and power it from the psu or something like that (I never use usb + anything else: it's either all via usb or all via psu). Couple of ICs and a couple of mosfets. I never needed an op-amp or a bjt either, true story!

I appreciate your passion about the AD2; I'm sure it's a wonderful product. But for my current needs is basically useless, throwing away 260+$ (plus shipping and tax). Perhaps in the future I will be able to appreciate its power and versatility and buy one of its descendants!

Right now it falls in the "I kinda know what it does, I actually do not know how can people find it useful" category, right with the arb-generators.

[james_s]

Do I really have to point out that I'm not the only one here who has used gear? Thousands of people buy used gear and for most it works out just fine. Older higher end equipment tends to be very well made.

I was talking about your experience with a Chinese unit, not even taking things like confirmation bias into account.

Will anybody say with a straight face that low end gear like Rigol, Siglent, etc are anywhere close to the quality of slightly older HP/Agilent/Tektronix gear that probably cost 10x as much when new?

How many cheap Chinese power supplies has Dave shown in his videos that were crap? Some are decent, but I'll take a used HP *any* day over a new hobbyist brand at the same price.

[Mr. Scram]

Will anybody say with a straight face that low end gear like Rigol, Siglent, etc are anywhere close to the quality of slightly older HP/Agilent/Tektronix gear that probably cost 10x as much when new?

How many cheap Chinese power supplies has Dave shown in his videos that were crap? Some are decent, but I'll take a used HP *any* day over a new hobbyist brand at the same price.

Top end brand name equipment has been shown to have defects and issues as well, both when brand new and after years of use. The new Keysight power supplies turned out to have quite a few rather relevant bugs in it and it's not the first time that happened to them. Besides, it's not a new HP versus new Rigol discussion. It's a 20 or 30 year old and often beaten up HP versus brand new Rigol with warranty discussion. What's your cup of tea depends on your needs and wishes, but it's not as clear-cut as you make it seem here. Especially a lot of the HP branded stuff is now getting so old that it really needs to be treated on an as-is basis.

[Wolfgang]

... and dont forget RIGOL and maybe others in fact *made* some low-end HP/Agilent/Keysight equipment as OEMs.

[Inno_Dim]

Well I'm a newbie here, so please be kind to me.
It happens to own a korad KA3005P, so far so good. But when I use it to recharge lithium batteries voltage drops across my crappy-long wires, so I had to adjust every now and then, the output voltage in order I have fixed voltage across my load (i.e. batteries)
To overcome this issue I decided to add remote sensing feature in my korad. What I did is described here:
https://www.instructables.com/id/Remote-Sensing-for-Korad-Power-Supply/


So now if anyone goes to buy a korad, should have in mind that with virtually no cost, and with some labor time can add remote sensing capability to korad.
Feel free to ask me any question about this modification and/or suggest me ways to improve it.

[rstofer]

Hi,

"well, even easiness and usability are personal judgements."
Well, Yes and No 
Of course does personal judgement play an important role, but there are certain common design rules that lead to an easy and intuitive layout.

Examples:
Rigol DP832A:
- distance between the connectors is all the same and quite close --> arrange + and - connectors as (channel)groups for easy identification

Manufactured shorting links and shorting jumpers assume a connector spacing of exactly 3/4".  So do dual plugs.
 Dave was very critical of a piece of equipment where the manufacturer deviated from this standard.

https://www.pomonaelectronics.com/products/hardware/double-banana-plug-solderless

[Jwillis]

Hey there.
I am in need of a PSU. The old unit that was gifted me (it has at least 30 years) is not enough anymore.
I usually do not do much power-stuff, and also am kinda on a budget (I can spend up to around 400€ if the benefits are so huge to justify that, but perhaps I do not need expensive things).

I basically need:

• at least two outputs
• at least two of the outputs should be able to go to ~20/30V
• 2A are enough, although I know that 3A is usually quite standard. I normally do not need more than 1A
• short circuit protection is ESSENTIAL since otherwise I would blow up everything after the first 10 minutes
• perhaps, as a beginner, there's something else I need that I do not know
• best if seller is europe-based

After gathering all these requirements, I found (on a seller website) the following products. I actually do not know how to choose because basically I cannot justify the price difference in any way. Also, albeit on a budget, I do not want to buy absolute crap. So here we are

Number one is a KORAD KD3305D (never heard of KORAD before) https://www.welectron.com/Korad-KD3305D-Labornetzteil_1 Datasheet. It's really cheap, and it seems to have everything I need, although I do not know whether it is ok/reliable.

Next is another KORAD, KA3305P https://www.welectron.com/Korad-KA3305P-Benchtop-Power-Supply Datasheet. It costs a little more. No clue what the difference is, apart from having a single knob instead of one knob per channel…

Now I've got a SIGLENT, SPD3303C https://www.welectron.com/Siglent-SPD3303C-Benchtop-Power-Supply . It costs almost 100€ more than the first Korad. Apart from the siglent brand, I do not know why since it delivers less power than the korad at a lower resolution too.

Finally, the monster, which is basically kinda an overbudget thing (but if it's remarkably better than the others I'm willing to make), the Siglent SPD3303X-E, which costs 2.5 times the first korad; https://www.welectron.com/Siglent-SPD3303X-E-Benchtop-Power-Supply datasheet. It seems that the price is justified by a nicer interface and a better connectivity which I do not care about, but perhaps there's more to it I'm missing.


So after all of this I actually do not know. Is there anything better out there for my purpose, that I simply ignored just going to one seller? Which one do you think is best for my needs?

Thanks to anyone who will help me choose and understand better. Cheers

Many bells and whistles tend to be unused by average hobbyists.
Although the Siglent is nice ask yourself if you need data linking. That's an extra that brings up the price.Data linking is used in an assembly line environment so all your workers are running the voltages they need for the station they are at.
Memory is nice if your a total klutz  because you can lock in a parameter and not worry as much. But do you really need it.
2 or more  channel  supplies can be paralleled or put in series so a 2 channel 0- 3 amp 0-30v configured for parallel will give 6amps 0-30v. and series will give 3amp at 0 -60v.
Personally I find that the less complex something is the less likely things go wrong and easier to repair.
400 euro here is over 600 dollars .Heck I would buy 2 simple power supplies instead of one fancy one.But hey its your money.

[james_s]

I feel the same way, for hobby bench use nothing beats old fashioned analog knobs on a power supply. Simple, reliable, easy to use, the computerized bells & whistles just add more complexity and more to go wrong.