Highest power offline SMPS in plastic enclosure (no fans)

[cupoftea]

Hi,
After several hours searching, i find the highest power SMPS i can find in all plastic , fanless enclosure is the LPC-150 from meanwell...

LPC-150

https://www.meanwellusa.com/upload/pdf/LPC-150/LPC-150-spec.pdf

However, it is only allowed down to 180VAC minimum. Also, it must be derated in power when VAC goes below 200VAC....being only allowed 120W at 180VAC.
Also, it has overtemperature shutdown without saying where this temperature is measured.

Do you agree, you cannot get above 150W offline in plastic , fanless enclosure?

____________________________________________________________________________________________________________________
This one is all-plastic and fanless...

https://www.amazon.co.uk/Charger-Compatible-G703GX-EV017FR-G703GS-WS71-ADP-280BB/dp/B09FSTB6YK/ref=sr_1_21?c=ts&keywords=Laptop+Chargers+%26+Power+Supplies&qid=1677891573&refinements=p_n_feature_two_browse-bin%3A50889726031&rnid=50889722031&s=computers&sr=1-21&ts_id=430484031

...and claims to do 280W from 100-265VAC......but its a laptop charger, and who knows, it probably only charges at that rate if the internal temperature is low?...it may well derate down to 100W as internal temperature rises.
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Also, what external case temperature would the following metal cased, 150W SMPS get to when at 100VAC and full load, and in 40degC ambient temperature. ...Would you scald yourself if you touched it?

XLG-150

https://www.meanwell.com/Upload/PDF/XLG-150/XLG-150-SPEC.PDF

 

[KlausST]

Hi,

I don't agree. It still mainly is a problem of dissipated power and enclosure size.

Klaus

 

[cupoftea]

Thanks, AYK, the next question would come as follows....what size plastic enclosure would be acceptable for an offline 100-265AC SMPS, with operation up to 45degC ambient, at 300W?
(i think such a thing would be way too large to be a sellable product)

Also, please answer for...
200W
100W
?

Do we at least agree that a MOSFET in an offline SMPS should preferably not run with junction any hotter than 105degC?......otherwise it will succunmb fairly quickly, to expansion/contraction damage which is likely to result in significantly shortened lifetime.?

BTW, that above comment is what you hear from "old-timer" engineers, all over the place...you want see it in MOSFET literature.....its "in_the_club_knowledge"....a Trade secret.
______________________________________________________________________________________________
IMHO, an offline SMPS in a totally sealed plastic enclosure, operating at 300W, down to 120VAC, and at 40degC ambient, is almost an absurdity. (?)
.....it would need to incorporate internal temperature sensing and reduce its power output as it overheated....and as such, even though sold as a "300W" SMPS....it would not really be.

 

[mtwieg]

Of course there's no upper limit on power, so long as there's no upper limits on size or efficiency.

I've definitely had laptop adaptors that could provide >200W continuously. They have extremely efficient circuits to shrink the form factor. Obviously if you shove the thing under a blanket it will overheat and throttle its output, but in normal use cases they're fine.

It might be more plausible to derive a limit on power dissipation per unit volume or surface area. But even that is going to be very context dependent.

 

[cupoftea]

I've definitely had laptop adaptors that could provide >200W continuously. They have extremely efficient circuits to shrink the form factor. Obviously if you shove the thing under a blanket it will overheat and throttle its output, but in normal use cases they're fine.

Thanks, as you kindly say, it throttles back....just as i thought.....the question is , and its impossible to find out...at what situation does it start to throttle back?

I am guessing that you were running it at 220VAC?.....and also, how did you know it gave 200W?......and would it still give 200W after an hour? (it may well have a timed throttle-back, and in fact, is strongly likely to)

I would say that 200W in any marketable kind of size, and at 100VAC, 40degC, Max load, is just not do-able...unless you want a very short lived power supply/charger.

There are no plastic case, 100-265VAC offline SMPS's on the market at greater than 150W. Ive searched and there are none.
(apart from Chargers and LED drivers, which as we tend to know, have "throttle-back")

 

[mtwieg]

Thanks, as you kindly say, it throttles back....just as i thought.....the question is , and its impossible to find out...at what situation does it start to throttle back?

I am guessing that you were running it at 220VAC?.....and also, how did you know it gave 200W?......and would it still give 200W after an hour? (it may well have a timed throttle-back, and in fact, is strongly likely to)

I know because my job was to benchtest one, with an electronic load. Can't say very much because of NDA, but mains voltage was ~110VAC. Enclosure hot spot was within limits (75C, IIRC) at steady state. No idea what internal temperature was. Measured efficiency was >96%, so it was it was only dissipating <10W total.

 

[cupoftea]

Thanks,
May ii ask, if it was associated with this....?...

https://www.edaboard.com/threads/cooling-inside-of-small-sealed-plastic-enclosure.272299/

...i note you have been in the "plastic enclosure space" yourself.

As you suggest, knowing the internal temps is essential when doing offline 200w in plastic. 10W is a lot in a plastic case.

 

[cupoftea]

A total search of the market, reveals that there are absolutely no offtheshelf offline SMPS for sale, above 150W, when in a totally sealed plastic case and from 100-265VAC.

In fact, that figure may even be "above 100W".

Yes there are LED drivers and Chargers available like that...but they simply do not count, as they throttle back their output when temperatures are high.....even if they only start throttling back some half hour after the temperature goes high...they do throttle back....so they do not count in this study,

 

[mtwieg]

Thanks,
May ii ask, if it was associated with this....?...

https://www.edaboard.com/threads/cooling-inside-of-small-sealed-plastic-enclosure.272299/

...i note you have been in the "plastic enclosure space" yourself.

No completely different project.

As you suggest, knowing the internal temps is essential when doing offline 200w in plastic. 10W is a lot in a plastic case.

"a lot"? How so? Show your work.

Yes there are LED drivers and Chargers available like that...but they simply do not count, as they throttle back their output when temperatures are high.....even if they only start throttling back some half hour after the temperature goes high...they do throttle back....so they do not count in this study,

Any good power supply will "throttle back" if its temperature rises enough for some reason. This is a feature, not a bug. According to your criteria I suppose every PSU with OTP would be excluded, since if you put it in a room with Ta=85C their output would be derated greatly?

What matters is whether that derating applies in reasonable use cases. It's definitely true that some of these "brick" adaptors can't live up to their nameplate specs even in normal use (I'm recalling the external power adaptors for some gaming consoles were notorious for failing if you put them on thick carpet, or too close to the console they were powering). That's attributable to poor design. But there is no upper limit on output power. It's just a matter of getting high efficiency and properly sizing/designing the enclosure.

 

[cupoftea]

Any good power supply will "throttle back" if its temperature rises enough for some reason. This is a feature, not a bug.

Thanks, though the changers and led drivers throttle back far more aggressively than standard offline SMPS. That is why we cannot consider them in analysis. I am not speaking about standard OTP which as you kindly say, exists in virtually all PSUs.

According to your criteria I suppose every PSU with OTP would be excluded, since if you put it in a room with Ta=85C their output would be derated greatly?

....Thanks but not talking about this....talking about the far more agressive throttling back seen in chargers and led drivers......

It is a fact that other than chargers and LED drivers, offline SMPS with power >150W and from 100-265VAC cannot be found offtheshelf for purchase anywhere in the world. (in total enclosed plastic with no vent holes) They are all metal case, or have fans.

I certainly agree that its just a case of sizing it so it works...but my premise is that the size needed for totally enclosed plastic, and 100-265VAC, at 150W+ means that that size is too big to be a marketable product.....The lack of market offerings in 100-265vac, 150w+ and totally sealed plastic suggests that this is a bona fide point. Thats across the entire world...you cant find offtheshelf as described.

(except of course chargers and led drivers for reason discussed)

 

[FvM]

I have 200W 100-240V AC adapter for the docking station of my Zbook mobile workstation. 97 x 170 x 26 mm.

 

[cupoftea]

Thanks, but that is mostly a charger.

 

[KlausST]

Hi,

often called a charger. In my eyes wrongly. It has no charging function, not caring about battery type, not adjusting charging current.
It's a constant voltage output supply. As one expects it from a regular power supply.

The nameplate should tell.

Klaus

 

[cupoftea]

often called a charger. In my eyes wrongly. It has no charging function, not caring about battery type, not adjusting charging current.

Thanks, though i believe it merely provides a constant Voltage to the charger in the product...as such, albeit indirectly , its main power function is battery charging...that device, the "Zbook mobile workstation" has a large battery inside it , and that PSU, is responsible for the charging of it....so really, its a charger, in terms of its mains purpose....the internal charger (the one in the zbook( is highly likely to throttle back so that shown PSU doesnt have to do it.....to preserve the life of the PSU (charger)

Zbook mobile workstation
"HP Long Life 6-cell, 83 Wh Li-ion polymer"

 

[KlausST]

Hi,

What makes a charger a charger?
What makes a power supply a power supply?

For me personally:
a power supply has about constant output voltage, independent of current.
A charger has meaningful V - I behaviour to put energy into a battery while not overcharging, taking care to maintain high l lifetime and high charging cycles ... and maintain safety (avoid explosion of battery).

A power supply is something universal, it may be used to power any electric or electronic device that meets voltage and current specification.
A charger is not designed to power typical electric or electronic loads.

The PSU of my tablet shows 19.2V, 4.5A. I already used it successfully to power a stepper motor application ... and a (bluetooth) amplifier for speakers. Impossible for a charger.

Klaus

 

[cupoftea]

Thanks, and thats 86W as you know.
The context here is that any SMPS used as primarily a charger...or "PSU for a charger", is likely to throttle back , or the charger it supplys is likely to...so it cannot be said to be "offline, 100-265VAC AND 150W+ in a sealed plastic case."

I feel certain that if "offline, 100-265VAC AND 150W+ in a sealed plastic case" was possible, Meanwell, TDK, Recom, Traco, XP, Artesyn, Murata, Mornsun, etc etc, would have done it by now....but they haven't.

 

[mtwieg]

What makes a charger a charger?
What makes a power supply a power supply?

Probably the same thing that makes a Scotsman a True Scotsman.

That is, web search hits.

 

[KlausST]

Hi,

Like this

Differences between a Power Supply and a Charger

Haredata Electronics is the leading UK Provider for AC/DC industrial and Medical Switch Mode Power Supplies, USB Power, Battery Chargers, Battery Packs, Industrial Components and Full Electronic Powertrain Vehicle Technology We offer Industrial and Medical Grade Power Solutions available...

www.haredataelectronics.co.uk

Klaus

 

[FvM]

Curious speculation about "charger" specified as constant voltage source but though being different from a voltage source. Only to save your claim that you don't find > 150 W sealed power supplies on the market.

For your info, the device is primarily supplying the docking station and the computer in stationary operation. Up to 200 W continuously.

 

[cupoftea]

For your info, the device is primarily supplying the docking station and the computer in stationary operation. Up to 200 W continuously.

Thanks, its certainly of great interest....but we know what would be the next questions..
1....What is the ambient temperature where you measure the 200W continuous?
2....What is your VAC input?
3....For how long did you see it operate at 200W?
4....How do we know it doesnt reduce its voltage by a volt or so when it wants to throttle back, and then the downstream circuit in the zbook reads this, and then reduces the charger current draw?

Its winter, so i guess you are in a 20degc room, and you are using 220VAC(?)

Also, your docking station probably has a nice support column for the power supply, such that ventilation air can pass freely over all of its surfaces?

Plastic casing is massively beneficial to customer, because it doesnt burn their hands when they touch it, so why havent Meanwell, TDK, Recom, Traco, XP, Artesyn, Murata, Mornsun, etc etc, done a "100-265vac, 150w+ and totally sealed plastic " ?

(As you know, i am ignoring here, the fact that offline plastic sealed SMPS when hard switched, cannot pass radiated emissons....unless they have total metal foil lining)