Which AC adapter for Asus RT-N18U

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wakatana
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PostPosted: Mon Sep 20, 2021 22:37    Post subject: Which AC adapter for Asus RT-N18U Reply with quote
Can somebody please post photos of Asus RT-N18U AC adapter? I do not have original so I need to properly set universal AC adapter. And I cannot find it anywhere on the net. Thank you
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kernel-panic69
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PostPosted: Mon Sep 20, 2021 23:37    Post subject: Reply with quote
The spec according to wikidevi and user manual is 12VDC 1.5A, but this is a BCM47081A0 (800 MHz) device. I have seen similar devices use a 2.5 or 3A power adapter. This information is on the router label, if I am not mistaken.

https://wikidevi.wi-cat.ru/ASUS_RT-N18U

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mwchang
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PostPosted: Tue Sep 21, 2021 6:52    Post subject: Re: Which AC adapter for Asus RT-N18U Reply with quote
wakatana wrote:
Can somebody please post photos of Asus RT-N18U AC adapter? I do not have original so I need to properly set universal AC adapter. And I cannot find it anywhere on the net. Thank you


English manual of Asus RT-N18U: https://dlcdnets.asus.com/pub/ASUS/wireless/RT-N18U/E9415_RT_N18U_Manual.zip

On page 8 of its English manual:
Code:

NOTES:
•    Use only the adapter that came with your package. Using other
adapters may damage the device.
•    Specifications:
DC Power adapter DC Output: +12V with max 1.5A current;
Operating
Temperature
0~40o
C Storage 0~70o
C
Operating Humidity 50~90% Storage 20~90



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kernel-panic69
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PostPosted: Tue Sep 21, 2021 13:31    Post subject: Reply with quote
I run replacement adapters that go up to 5 or 6A without issue. It's only going to draw what it needs, and if you add a USB fan, you don't see performance dives. Some examples of similar SoC devices and their current ratings:

https://wikidevi.wi-cat.ru/TRENDnet_TEW-811DRU (2A)
https://wikidevi.wi-cat.ru/Arcadyan_WA9117A-AC23 (2.5A)
https://wikidevi.wi-cat.ru/Linksys_EA6300_v0.1 (2A)
https://wikidevi.wi-cat.ru/Linksys_EA6300_v1 (3A)
https://wikidevi.wi-cat.ru/D-Link_DIR-868L_rev_A1 (2.5A)
https://wikidevi.wi-cat.ru/Buffalo_WZR-1166DHP (3A)
https://wikidevi.wi-cat.ru/Buffalo_WZR-1750DHP (4A)
https://wikidevi.wi-cat.ru/ASUS_RT-AC56S (2A)

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wakatana
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PostPosted: Tue Sep 21, 2021 22:03    Post subject: Reply with quote
Thanks for reply. AFAIK larger ampere will not break the device, but larger voltage will. But I still do not know if center of barrel connector is positive or negative - and It is not show on my device also. My universal AC adapter has two barrels (larger and smaller - currently I am not at home but I guess larger has G letter on it) which will fit. Thanks
bushant
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PostPosted: Tue Sep 21, 2021 23:07    Post subject: Reply with quote
https://wikidevi.wi-cat.ru/ASUS_RT-N18U


rt-n18u.jpg
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rt-n18u.jpg


jwh7
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PostPosted: Wed Sep 22, 2021 0:27    Post subject: Reply with quote
Asus likes to use abnormal barrel sizes for their power adapters, but in 30+ years of messing with such things, I've only ever seen one device with the center as negative. As a corollary though, I've known many people whose center is negative. Cool
wakatana wrote:
AFAIK larger ampere will not break the device, but larger voltage will.
Tru dat. Smile Though regulated vs non- supplies are another variable.

12V adapters have two common sizes, but there are uncommon ones too. Looking at the FCC docs, it seems common though. Unless you're going to run high power draw USB devices, even a 12v 1A supply would be fine, but you could probably find a 2-3A supply for the same price. I've got some 12V 3-5A spec'd devices that I've tested to only draw 0.5A under load (multiple LAN and wifi devices running speedtests... and a USB SATA drive). You might as well get an adapter w/ a V or VI efficiency rating though.

Where are you located? You could try local Goodwill stores to find an adapter that will work. Take a multimeter to test it.

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Last edited by jwh7 on Wed Sep 22, 2021 0:32; edited 1 time in total
kernel-panic69
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PostPosted: Wed Sep 22, 2021 0:30    Post subject: Reply with quote
jwh7 wrote:
As a corollary though, I've known many people whose center is negative. Cool

I'm sitting right here. No need to be bashful Wink

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jwh7
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PostPosted: Wed Sep 22, 2021 0:31    Post subject: Reply with quote
kernel-panic69 wrote:
jwh7 wrote:
As a corollary though, I've known many people whose center is negative. Cool

I'm sitting right here. No need to be bashful Wink
LOL

As another aside...
wakatana wrote:
but larger voltage will.
I helped out a coworker many years ago who was having occasional network issues. His wife replaced their Linksys B router with a D-link or Belkin G router. Then they had -no- network. I found that she replaced the router w/o changing the power adapter. The Linksys was 12V, the new one was 5V. And fried. /facepaw
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mrjcd
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PostPosted: Wed Sep 22, 2021 3:20    Post subject: Reply with quote
jwh7 wrote:
I helped out a coworker many years ago who was having occasional network issues. His wife replaced their Linksys B router with a D-link or Belkin G router. Then they had -no- network. I found that she replaced the router w/o changing the power adapter. The Linksys was 12V, the new one was 5V. And fried. /facepaw

Wrong voltage CAN get you in trouble Laughing
I remember the first WAP54Gv1 & v1.1 were 5v
Had couple along with many other WAP54G & WRT54G that all were 12v ... always had to make sure what was what.
I never killed one but always double checked.
Funny how some stuff like that sticks in the ol brain pan Twisted Evil
mwchang
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PostPosted: Wed Sep 22, 2021 12:49    Post subject: Reply with quote
bushant wrote:
https://wikidevi.wi-cat.ru/ASUS_RT-N18U

So is there standard for the positive and negative pins among AC-DC adapters? It can be a nightmare if there is NOT one... Smile

And I don't usually find universal AC-DC adapters to have a switch for the negative and positive pins, but just for output voltage selection. I do see 2-pin DC ends. Maybe that's the reason why.


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Last edited by mwchang on Wed Sep 22, 2021 12:54; edited 1 time in total
mwchang
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PostPosted: Wed Sep 22, 2021 12:51    Post subject: Reply with quote
wakatana wrote:
Thanks for reply. AFAIK larger ampere will not break the device, but larger voltage will. But I still do not know if center of barrel connector is positive or negative...

Let me have a look at the AC-DC adapter of my RT-N18U after I turn it off later today!

I thought there should be a standard .....Smile


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bushant
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PostPosted: Wed Sep 22, 2021 13:23    Post subject: Reply with quote
mwchang wrote:
So is there standard for the positive and negative pins among AC-DC adapters? It can be a nightmare if there is NOT one... Smile


Although I know they do it both ways it seems having the outer barrel positive
is asking for trouble easily getting shorted across a ground somewhere by mistake Shocked
Nevertheless they are easily reversed with wire cutters and electrical tape. solder optional Rolling Eyes
jwh7
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PostPosted: Wed Sep 22, 2021 15:53    Post subject: Reply with quote
bushant wrote:
mwchang wrote:
So is there standard for the positive and negative pins among AC-DC adapters? It can be a nightmare if there is NOT one... Smile
Although I know they do it both ways it seems having the outer barrel positive is asking for trouble easily getting shorted across a ground somewhere by mistake Shocked
Yes, that. Wink As I said, I've only ever seen center negative once, and that was some old (even at that time) datalink engineering tool like 20 years ago. We also used 9V AC power adapters back then; also for a datalink J1587/1708 tool.

If one -really- wants to verify negative, use a multimeter to find continuity from the outer antenna casing. Or take the router apart...

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# NAT/SFE/CTF: limited speed w/ DD # Repeater issues # DD-WRT info: FAQ, Builds, Types, Modes, Changes, Demo #
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WRT54G{Lv1.1,Sv6}@250
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kernel-panic69
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PostPosted: Wed Sep 22, 2021 15:59    Post subject: Reply with quote
USB port shield is a known good ground on devices with a USB port.
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