New miniature programmable DC power supply - FNIRSI DPS-150

[ptluis]

Did you tried RISE instead of peak detect?

Hi

I don't know what RISE is.
My cheap scope has the acq. modes: Normal - Hi-Res - Peak - Average.

Thank you.

My mistake sorry,

Aquisition mode I use normal instead of peak

Trigger type I use Edge and slope Rise

After you check for ripple at no load, apply some load at output and watch the real ripple of the ps when stressed

[Aldo22]

@ptluis
It depends on whether you don't want to miss a spike (Peak detect).
For ripple measurement, Hi-Res is probably the best for my scope.

I'll check with load later.

Thank you.

[ptluis]

@ptluis
It depends on whether you don't want to miss a spike (Peak detect).
For ripple measurement, Hi-Res is probably the best for my scope.

I'll check with load later.

Thank you.

Well you should try and see what option gives you the best results, but in ripple measurements were not looking for spikes. that's my 2 cets

[Aldo22]

Well you should try and see what option gives you the best results, but in ripple measurements were not looking for spikes. that's my 2 cets

I understand that this is a good way to measure ripple.
But actually the higher frequency noise of my (other) SMPS bothers me even more...
It's not that easy: https://www.4niev.com/switching-power-supply-noise/ 

But in any case, my self-built PSU hasn't shown any worrying interference in any range so far. 
And to get back on topic, I think it would be a good source for the DPS-150 (for low power applications).

[ptluis]

Well you should try and see what option gives you the best results, but in ripple measurements were not looking for spikes. that's my 2 cets

I understand that this is a good way to measure ripple.
But actually the higher frequency noise of my (other) SMPS bothers me even more...
It's not that easy: https://www.4niev.com/switching-power-supply-noise/ 

But in any case, my self-built PSU hasn't shown any worrying interference in any range so far. 
And to get back on topic, I think it would be a good source for the DPS-150 (for low power applications).

Your self made psu operates differently from  smps  (switch mode power supply) so the smps always show spikes, some show higher spikes other less, depending on the quality of the filtering, with aquire mode set to peak, your calculated pk to pk value is higher meaning ripple measured will not be real.

The dps-150 is a dc-dc buck converter that also produce spikes although at lower values and in this case it's possible to even decrease them to lower values by using a ceramic capacitor with low esr at the output, the low esr is the key.

If you don't want any ps noise on your dut you should power it using batteries as source of power, and use analog voltage regulators like the 7812 for eg. Also in audio electronics a clean PS is preferable.

[Fungus]

Yeah, something like this is probably useless for Audio.

[Aldo22]

Here are the ripple measurements of my own PSU (12V), in case anyone is interested.
Above without load, below with 1.5W.
I will hardly need more power with this ps.
That's good enough for me.

[ptluis]

Here are the ripple measurements of my own PSU (12V), in case anyone is interested.
Above without load, below with 1.5W.
I will hardly need more power with this ps.
That's good enough for me.

Now with the load, change the aquire mode to average 8 and you'll get a more stable representation of the ripple of your ps, meaning a better visualization of the ups and downs of the stabilization.

[Aldo22]

Now with the load, change the aquire mode to average 8 and you'll get a more stable representation of the ripple of your ps, meaning a better visualization of the ups and downs of the stabilization.

These screenshots are taken in "Hi-res" mode.
This is also a type of averaging, but does not iron out as much as the “Average” mode.
I think that's fine. 250uVrms ripple at 12V is OK. I don't think I can (or want) improve on that.

Thanks.

[ptluis]

Now with the load, change the aquire mode to average 8 and you'll get a more stable representation of the ripple of your ps, meaning a better visualization of the ups and downs of the stabilization.

These screenshots are taken in "Hi-res" mode.
This is also a type of averaging, but does not iron out as much as the “Average” mode.
I think that's fine. 250uVrms ripple at 12V is OK. I don't think I can (or want) improve on that.

Thanks.

High res won't "clean" the signal as much as average does and that's why average is nice to "make the signal thinner" by removing the less constant acquired points and keep the most stable ones. It's a way of loosing fat 

[Aldo22]

High res won't "clean" the signal as much as average does and that's why average is nice to "make the signal thinner" by removing the less constant acquired points and keep the most stable ones. It's a way of loosing fat 

Yes, that's where we reach the limits of my $150 scope.
You need a stable trigger for average mode.
But it doesn't manage to do that in the uV noise salad.

But I remembered that it has a line trigger mode (50Hz)
This works a little, but you can clearly see the limits.
In the attached screenshot: 1.02mV/div ("zoomed")
If you squint your eyes a little, you can see the capacitors discharging.
But for $150 it's not that bad...   

[ptluis]

High res won't "clean" the signal as much as average does and that's why average is nice to "make the signal thinner" by removing the less constant acquired points and keep the most stable ones. It's a way of loosing fat 

Yes, that's where we reach the limits of my $150 scope.
You need a stable trigger for average mode.
But it doesn't manage to do that in the uV noise salad.

But I remembered that it has a line trigger mode (50Hz)
This works a little, but you can clearly see the limits.
In the attached screenshot: 1.02mV/div ("zoomed")
If you squint your eyes a little, you can see the capacitors discharging.
But for $150 it's not that bad...   

That's where 500uv/v scopes come in.
And you know, it's better to have a 150€ scope that allow us to "see" electricity that have nothing and just guess. I use 70 bucks toy scopes like the dso2512g and the dpox180h for quick checking signals and only use the better ones when I need more accurate info on what's going on.

[Aldo22]

That's where 500uv/v scopes come in.

Sure, but I can actually see enough. 
Delving deeper into microvolts doesn't give me any additional information that could be of practical use at the moment.

obrigado

[ptluis]

obrigado

"De nada" 

We're here to help each other 

[Aldo22]

If you increase the number of acquisitions in average mode, you see a pretty clean signal.
It's amazing what can be achieved with a few (cheap) tricks. 

[ptluis]

If you increase the number of acquisitions in average mode, you see a pretty clean signal.
It's amazing what can be achieved with a few (cheap) tricks. 

Yes and it's a way to see if there's a problem with the rectification
bridge. if you have a not so good diode in the rectification bridge you will see it!
 but average mode is not good for signals when you can't get a stable trigger in this case hires mode could help better.

[Eltax1693]

I'm on firmware 1.0
Any newer version available?

Thank you

[Stray Electron]

Uout >=5V
Shame!!!

I don't know what Uout is.  Do you mean Vout?
If so, the device goes from 0V to 30V.

    "U out" is very commonly shown on German made electronics instead of "V out".  It must be a language thing. 

    This is the explanation that I found online.  One of our German members can probably tell us if it's correct.

But now, I found, an explanation plausible and maybe also a historic for that, which is as follows: Germans started denote voltage by the letter "U", probably because that letter was largely unused and so couldn't be confused with anything else. It also came up by its etymology, since "U" stands for Unterschied, which in German means "difference"; very fitting since voltage is obviously the same as potential difference.

[xKertx]

Uout >=5V
Shame!!!

I don't know what Uout is.  Do you mean Vout?
If so, the device goes from 0V to 30V.

    "U out" is very commonly shown on German made electronics instead of "V out".  It must be a language thing. 

    This is the explanation that I found online.  One of our German members can probably tell us if it's correct.

But now, I found, an explanation plausible and maybe also a historic for that, which is as follows: Germans started denote voltage by the letter "U", probably because that letter was largely unused and so couldn't be confused with anything else. It also came up by its etymology, since "U" stands for Unterschied, which in German means "difference"; very fitting since voltage is obviously the same as potential difference.

"U" is not german. It is used  in europe overall.

[Aldo22]

"U" is not german. It is used  in europe overall.

As far as I know, "U" means “electrical voltage” (German: Spannung) and "V" is the unit Volt.
The "U" comes from the Latin word “urgere”.
It's like "I" ("intensité du courant") and "A" (Ampere).

In English "V" is used for the phenomenon (in formulas) as well as for the unit.

[Fungus]

OK, I bit the bullet and ordered one on Aliexpress. 

I'm gonna get a USB C charger to power it, it seems like the best/easiest option.

FWIW: Ikea make awesome phone chargers and they're super cheap. Their 30W "SJÖSS" should be enough for me (supports 20V, 1.5A) and they're only 7 Euros.

I'm gonna get a bunch more of their little SMÅHAGELs as well. They're awesome for powering 5V gadgets, and only 3 Euros(!)

[Aldo22]

OK, I bit the bullet and ordered one on Aliexpress. 

Congratulations!
I'm still looking for a potential use for this thing.
It's like the Fnirsi SG-003A: somehow I'm tempted to buy it, if only I could find a tiny rational reason to do so... 

[4thDoctorWhoFan]

I'm still looking for a potential use for this thing.
It's like the Fnirsi SG-003A: somehow I'm tempted to buy it, if only I could find a tiny rational reason to do so... 

You can NEVER have to many power supplies. 
The same goes for multimeters. 

[Nominal Animal]

"U out" is very commonly shown on German made electronics instead of "V out".

Both U and V are common symbols for voltage; I've definitely seen both.  U is also used in physics for potential energy (as is V and Eₚ, too).

The situation is very similar to calling ⁷⁴W "tungsten" or "wolfram".  ("Wolfram" is the original one, stemming from the ore wolframite; "tungsten" derives from the scheelite ore, then called tungsten, and is Swedish for "heavy rock".  Basically, Scandinavian mountain miners used the former, German (and slavic miners later on) the latter, way back in the day.  The German miners just had a habit of naming their ores more imaginatively, )

In physics, many prominent physicists in the 1700s to early 1900s developed somewhat distinct patterns of notation, including which letters they used for which physical properties and measurables (especially U, V, and what superscripts and subscripts were used for).  Some even developed completely new notations; see e.g. Dirac or bra–ket notation.  Einstein notation in particular can throw even mathematicians off, but is very common in some areas of physics.

There is no specific correct notation.  It is just a matter of convention; whatever one is used to.  Claiming otherwise is just succumbing to a perceived authority, and rejecting individual thought.  Certainly, all the great scientists have changed notations whenever it suited them, simply because it is just a tool, a way to convey the ideas and expressions.

[DaneLaw]

OK, I bit the bullet and ordered one on Aliexpress. 

Congratulations!
I'm still looking for a potential use for this thing.
It's like the Fnirsi SG-003A: somehow I'm tempted to buy it, if only I could find a tiny rational reason to do so... 

They can be quite handy, these small SMPSUs and the ability to have a small adj. powersupply with a powerbank or LIPO cellpack.

and PD3.1 (28v/5A) powerbank with 140watt works well with either a 100W or 150W. 30/5A SMPSU.