Calculate the power supply for 10 LED Screen's

Hello guys!

i have a pretty simple question, but im not sure and i dont want to burn anything

I need to make an installation of 10 LED monitor of 18.5", but we dont have space to put a power supply for each one, so we are gonna put a bigger power supply for the 10 devices.

I bought a power supply for a laptop for this application, it has 150w, 19,5v and 7.7A

This is the specs of the LG screen:
V = 19v
A = 1,2 A
Cnsumption = 14,4 Wh

So, if we take the data of the monitor, we have:

Power = ( 19 * 1,2 ) = 22,8w -------- 228w for the 10 screen's
Consumption = (14,4wh) --------------------- 144w for the 10 screen's

So i dont know what value is the right one, maybe if the monitors only takes 14,4 watts i can use the laptop power supply... but what you say???

PD:
I'm gonna supply the 10 screens with a main cord of AWG 14 cable, with a cable for each monitor of AWG 22 cable.
Original power supply of the screen = 19v, 1,3A

Thanks!

Hi Dvid and Welcome to EDABoard,


Power supply should have enough power to handle load, in your case monitors. Voltage should be as monitor need 19V, but I dont think that 19,7V will be some problem, and current of psu can be higher then your load needs.

I dont think that laptop psu is good solution, and will not last long. My opinion is to use separate psu for each monitor.

If you have 10 monitors each need 1,2A, then you should have psu with at least 12A on 19V.

Check with digital voltmeter voltage from laptop psu is it 19,7V or little more, also check monitor original psu is it exact 19V or higher.

This is the specs of the LG screen:
V = 19v
A = 1,2 A
Cnsumption = 14,4 Wh

Click to expand...

This is not true.

Power in Watts = U x I = 19V x 1,2A = max 22,8W for each monitor!!!

Dont mix Wh and W this is frogs and grannies.

If one of your monitor with power of 22,8W works 1h he makes 22,8Wh.
If one of your monitor with power of 22,8W works 37min he makes 14,4Wh.

From where you get 14,4Wh data at all?


Where you find that LEDs monitors with that high power, you should pay attention and carefully buy products. LED monitors should have around 10W for that dimensions.


I think your monitor have 14,4W (not 14,4Wh) of power consuption and manufacturer give psu adapter with 19V 1,3A. 1,3A is max and monitor normally use 0,75A of current, but in peaks he drain more current, lets say during monitor startup.



:wink:

tpetar said:

Hi Dvid and Welcome to EDABoard,
Power supply should have enough power to handle load, in your case monitors. Voltage should be as monitor need 19V, but I dont think that 19,7V will be some problem, and current of psu can be higher then your load needs.

Click to expand...

Thanks!, for the answer tpetar!
I already check the voltaje of both PSU and both gives around 19,3v, so we are ok at this point.

tpetar said:

Hi Dvid and Welcome to EDABoard,
I dont think that laptop psu is good solution, and will not last long. My opinion is to use separate psu for each monitor.

Click to expand...

Yeah, but i really dont have space to put the PSU for each monitor, the only way i can do that is puting the PSU and the 120v AC line beside the data cable's (Ethernet, monitor, and USB, all of them around 10m)... i dont want to deal with EMI interference. I prefer to use DC voltaje to avoid this problem.

What is wrong with my laptop supply? i bought a really big one for a sony vaio, its seems to have a great quality and its reaaally heavy.

Andd i couldn't found a supply of 19v with more than 150w, the only way is making my own power supply but i dont have much time now, maybe later...

tpetar said:

Hi Dvid and Welcome to EDABoard,

If one of your monitor with power of 22,8W works 1h he makes 22,8Wh.
If one of your monitor with power of 22,8W works 37min he makes 14,4Wh.

From where you get 14,4Wh data at all?


Where you find that LEDs monitors with that high power, you should pay attention and carefully buy products. LED monitors should have around 10W for that dimensions.

Click to expand...

The back of the display gives me that data, that is why im confused, if the monitor power its 22,8w it needs to consump 22,8wh right?

But no... the back panel etiquette says:

14,4 wh

The model is this http://www.lg.com/mx/monitores/lg-E1942C

I think your monitor have 14,4W (not 14,4Wh) of power consuption and manufacturer give psu adapter with 19V 1,3A. 1,3A is max and monitor normally use 0,75A of current, but in peaks he drain more current, lets say during monitor startup.

Click to expand...

i think (and i hope) that you are right!

If the screen takes 14,4w, then my actual power supply can works, since i dont gonna turn on the screens all at the same time, maybe the PSU can deal with the peaks for a little moment:

**broken link removed**

SO i'm gonna try to measure the current of the monitor with my tester, and if i cant i will connect the PSU and see if can handle the current.

Or put two PSU (5, and 5 monitors for each one).

Greetings!

LG E1942C monitor power specification says 15W of power consumption and 0,3W in standby.

I see... so the most probably thing is a the 14,4 watts consumption.

I will test the installation with my 150w PSU, hope it works!

Thanks for helping!

You are on edge of PSU capabilities, also count peak currents during startup.

You can make test, try first one, then one more, then one more,....

Dont turn on all in the same time!