Power bricks

[Ergroilnin]

Hello,

 

I'd like to ask if there is any real difference between monitors having internal or external power bricks?

Obviously there is more cable mess with external ones, but other than that, do monitors with internal ones have some other issues? Like more coil whine, lower life expectancy (due to heating of the power element) etc.?

 

If I do not care about more cabling or slightly thicker display, is there any real reason to care about the internal/external choice?

[Poinkachu]

22 minutes ago, Ergroilnin said:

Hello,

 

I'd like to ask if there is any real difference between monitors having internal or external power bricks?

Obviously there is more cable mess with external ones, but other than that, do monitors with internal ones have some other issues? Like more coil whine, lower life expectancy (due to heating of the power element) etc.?

 

If I do not care about more cabling or slightly thicker display, is there any real reason to care about the internal/external choice?

Unsavvy about it, but,

 

Two things my brain automatically thought : 
With inbuilt PSU, probably hotter backside if the monitor is high power enough, and more annoying if the PSU breaks.

Though yea I don't think I ever had a monitor brick breaking, all I had is external though.

 

As for cabling, even if the PSU is inside the monitor, you'll still need to run a cable to the wall socket, no? Though the cable probably be thicker than external one's.

External PSU cable = Monitor to brick is dc power, usually thin cable. Brick to Wall is AC power, usually thick.

Inbuilt PSU cable = Monitor to Wall, AC power.

 

But yeap, I never owned a monitor with inbuilt PSU so I wouldn't know for sure.

 

22 minutes ago, Ergroilnin said:

If I do not care about more cabling or slightly thicker display, is there any real reason to care about the internal/external choice?

Probably not if that's the case.

[OhioYJ]

33 minutes ago, Ergroilnin said:

If I do not care about more cabling or slightly thicker display, is there any real reason to care about the internal/external choice?

I don't think realistically there is. Personally I prefer the internal. However it's not even on my radar when purchasing a monitor. I'm looking at panel type and other specs. Most of the power supplies these days are so efficient, and small that the heat and space they could add to the monitor just doesn't matter in most cases in my opinion. Especially since most monitors just don't draw that much power anyways.

 

I would say this is one of those things you could say in theory there are pros and cons, but in reality it just doesn't matter. 

[Thomas53]

The reason that modern monitors have external power bricks is that they can be built into thinner housings whereas the televisions they are derived from don't necessarily have that space limitation. 

[TudorFinalBosz]

@Ergroilnin

I've had 2 monitors with internal power source that got fried. An Iiyama and an AOC. Neither could be repaired. Both were getting as hot as a stove, you could fry eggs on them.

 

The monitors I currently have (an LG and a Philips) both have external brick and they get less hot and already lasted for 4-5 years without any issues.

 

So idk, it might depend on how heat insulation is done inside the monitor, maybe some good manufacturers manage to do it in a way that it's never a problem, but from my limited experience internal power source always makes the monitors hotter. And some components like capacitors might expire faster if exposed to excessive heat.

 

Hence my recommendation would be: always external power brick. It's also more easily replaceable if it goes kaput.

[mariushm]

2 hours ago, Ergroilnin said:

Hello,

 

I'd like to ask if there is any real difference between monitors having internal or external power bricks?

Obviously there is more cable mess with external ones, but other than that, do monitors with internal ones have some other issues? Like more coil whine, lower life expectancy (due to heating of the power element) etc.?

 

If I do not care about more cabling or slightly thicker display, is there any real reason to care about the internal/external choice?

External adapter ... makes the monitor thinner.  Removes a bit of the heat generated from inside the monitor to a separate location. 

It makes it easier for a manufacturer to just buy a mass produced brick from an OEM that takes care of all certifications and tests for various emission standards and all that legal stuff.  It also makes it easier for some manufacturers to bundle a cheaper brick (let's say only 80% efficient) with monitors sold in certain regions that are more price sensitive (ex Brazil, Africa, Russia, some asian countries) and bundle higher end bricks in more sensitive / picky regions. 

 

To give some idea, at work we bought some 23-24" 1080p monitors from LG, basic office stuff, and they came with a booklet that listed probably 20 different power adapters, for various regions and monitor sizes (bigger monitors need more power, as there's more leds in the backlight) 

 

It's not always cheaper to have external power, in the sense that there still has to be a small circuit board inside the monitor with fuses, with a dc-dc converter to produce 3.3v or 5v for the display processor, and also a dc-dc converter to power the led strips , basically the backlight controller. Rarely, the backlight is powered directly from the 12v-20v or whatever the brick supplies. Often the backlights need 40v/60v/80v to run, they're made with lots of small white or blue leds in series. 

 

With an internal power supply, they could design it really custom to produce exactly the voltages needed by the backlight driver, and the low voltages needed by the display process, the headphones/audio amplifier (if any) and so on 

 

 

[manikyath]

2 hours ago, TudorF said:

@Ergroilnin

I've had 2 monitors with internal power source that got fried. An Iiyama and an AOC. Neither could be repaired. Both were getting as hot as a stove, you could fry eggs on them.

 

The monitors I currently have (an LG and a Philips) both have external brick and they get less hot and already lasted for 4-5 years without any issues.

 

So idk, it might depend on how heat insulation is done inside the monitor, maybe some good manufacturers manage to do it in a way that it's never a problem, but from my limited experience internal power source always makes the monitors hotter. And some components like capacitors might expire faster if exposed to excessive heat.

 

Hence my recommendation would be: always external power brick. It's also more easily replaceable if it goes kaput.

i dont think i've ever had/seen a display's power supply fail.

 

on the note of replaceability though.. if you ever snag the cord on your external power brick, sure the brick can be replaced, but DC ports are fragile as hell compared to C13 sockets, and C13 sockets are VERY standardized, while for some reason DC ports just have to be special.

 

as for the supposed problem of extra heat inside the monitor.. monitors are kind of big by default, and the heat coming from the power supply is sort of neglible compared to the heat coming from the display itself. and most displays i've had were designed by competent engineers that put vents for that heat to escape along the pretty massive back side of the monitor. besides, you still need the backlight driver and voltage conversions with an external power brick so you're removing less heat than you might think.

[TudorFinalBosz]

19 minutes ago, manikyath said:

i dont think i've ever had/seen a display's power supply fail.

I did. Had a Benq whose power source got fried. Sent it back to service and they replaced the part. The monitor still works today, I gave it to someone, but the way they fixed it was a bit careless, so it has a slight darker patch in the area.

 

I agree that most of the heat doesn't come from the monitor power source, something like 35%. But I don't think it's that negligible. I can check this right now on some monitors and one big Sony tv and I get similar results: the power brick is hot, it feels like 40°C subjectively (don't have a tool to measure it). But yeah, the panel itself feels even hotter. It might make the difference between one capacitor surviving longer or not during scorching summers. Especially if it's a cheaper unit on which the maker didn't invest much R&D, so heat dissipation might have been their last priority.

[manikyath]

2 hours ago, TudorF said:

something like 35%.

i highly doubt it's more than 20%, likely a decent bit below that with modern day efficiency. and the power brick is hot because it's emitting all of it's heat trough a plastic case, which doesnt conduct heat all too well.

 

2 hours ago, TudorF said:

It might make the difference between one capacitor surviving longer or not during scorching summers.

it doesnt. like, actually, if you're picking internal/external over which will last the longest, that's entirely the wrong way to pick your monitor especially if you're buying manufactured garbage:

2 hours ago, TudorF said:

if it's a cheaper unit on which the maker didn't invest much R&D

if you buy cheap stuff the caps will die because they're garbage caps, not because they're 45°c rather than 40°c.

 

and on top of that.. external power bricks run hotter, because as i keep pressing on.. no vents, so the heat is stuck inside.

[TudorFinalBosz]

Also display manufacturers use power bricks to avoid all the regulatory complications of demonstrating their unit is safe to use with higher voltages.

A power brick simply delivers low voltage to the main unit directly and thus saves you the costs with regulatory compliance.

[Ergroilnin]

Thank you all for your answers, I won't care about this parameter at all when I buy new monitor then.