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koitsu
MVM
join:2002-07-16
Mountain View, CA
Humax BGW320-500

koitsu to dellsweig

MVM

to dellsweig

Re: Undersized Power supplies from Linksys.

Do people realise just how much power _FIVE_ amps is? I don't even have full-blown 2U rackmount servers with 6 disks that pull that much.

This sounds like utter nonsense. All one of these tools has to do is purchase a kill-a-watt unit (I have two), hook it up, and run it through tests over a 24-48 hour duration.

dellsweig
Extreme Aerobatics
MVM
join:2003-12-10
Campbell Hall, NY

dellsweig

MVM

said by koitsu:

Do people realise just how much power _FIVE_ amps is? I don't even have full-blown 2U rackmount servers with 6 disks that pull that much.

This sounds like utter nonsense. All one of these tools has to do is purchase a kill-a-watt unit (I have two), hook it up, and run it through tests over a 24-48 hour duration.
Did you bother to read the thread I refered to??

Have you read the datasheets for the devices being discussed??

Do you undderstand that a devices will DRAW as much power as needed - if the PS only supplies 1 Amp and the chipset needs more - well - I assume you know all this already
Automate
join:2001-06-26
Atlanta, GA

Automate to koitsu

Member

to koitsu
The amps being talked about are on the 12VDC side not the 120AC side so they are almost 10 times more than what you measure with a kill-a-watt meter. My guess is that 5 amps is overkill but 1 amp is not quite enough.

dellsweig
Extreme Aerobatics
MVM
join:2003-12-10
Campbell Hall, NY

dellsweig

MVM

said by Automate:

The amps being talked about are on the 12VDC side not the 120AC side so they are almost 10 times more than what you measure with a kill-a-watt meter. My guess is that 5 amps is overkill but 1 amp is not quite enough.
Exactly

Thane_Bitter
Inquire within
Premium Member
join:2005-01-20

Thane_Bitter to koitsu

Premium Member

to koitsu
said by koitsu:

Do people realise just how much power _FIVE_ amps is?
Sure, around 30.242 × 10^18 electrons per second.
It seems high but the supply voltage needs to be considered, at most dellsqeigs router is likely pulling less then 2 amperes of power, or put differently a reasonable 24 watts at most. P(watts) = V(volts) x I(amperes)

If it was drawing 5 amps at 120 volts (which it is not even capable of), he would have a desk sized space heater (and fire)
said by dellsqeigs :

The before and after views are telling - and as you can see from the dd-wrt thread - others are seeing and quantifying the same.
Accton' products (a certain Spanish company resells with the end user agreeing to certain promissory obligations) tend to get very flakey at lower power. In their case it’s not the lack of power, it’s what happens if AC power is briefly interrupted to the adaptor. The DC voltage drops low enough to lock-up the processor, but not low (or long) enough to reset it. The router jams till it is reset.

Linksys is saving a few bucks by using what likely is a lower cost adaptor. As long as the hardware is good (Linksys’ stuff general is), and it will take a 3rd party firmware (Linksys’ versions are poor), I would be happy to spend a few bucks and upgrade the adaptor to really make the router work.

koitsu
MVM
join:2002-07-16
Mountain View, CA
Humax BGW320-500

koitsu

MVM

Thanks folks. An EE-savvy friend of mine reminded me of the calculation formulas used for wattage and so on; 12V @ 5A is a heck of a lot less power than 120V @ 5A.

Said friend and I both read the dd-wrt.com thread, and it seems the majority of the focus/reports are coming from people who are intentionally increasing their transmit power way beyond the default scope of the router. For example, the OP is transmitting at the equivalent of 1.2W (yes, 1.2 watts). That's pretty major compared to the default these units come with, pushing ~45-60mW.

Can someone please clarify if this is truly a problem for the WRT* customer base as a whole, or only those who want higher signal strengths?

Bill_MI
Bill In Michigan
MVM
join:2001-01-03
Royal Oak, MI
TP-Link Archer C7
Linksys WRT54GS
Linksys WRT54G v4

1 edit

Bill_MI

MVM

Like Koitsu implies, there is much more to it that 1 current rating.

These power bricks are notorious for hype and snake oil, as well as ripple and bad transient response. There's a zillion little measurements in the power supply industry that may or may not be sensitive by the design of the unit (router) itself.

But I don't doubt for an instant Linksys may be using something just "good enough" because of cost. I believe the claims, just not some of the reasons. What may be needed is a *good* 12V@1A power source - not simply more current rating.

dellsweig
Extreme Aerobatics
MVM
join:2003-12-10
Campbell Hall, NY

1 edit

dellsweig

MVM

said by Bill_MI:

Like Koitsu implies, there is much more to it that 1 current rating.

These power bricks are notorious for hype and snake oil, as well as ripple and bad transient response. There's a zillion little measurements in the power supply industry that may or may not be sensitive by the design of the unit (router) itself.

But I don't doubt for an instant Linksys may be using something just "good enough" because of cost. I believe the claims, just not some of the reasons. What may be needed is a *good* 12V@1A power source - not simply more current rating.
Bill

I did nopt test under stock linky firmware but as I remember, stock linksys sets 28Mw for the transmit power.

Just for grins - I looked at my signal (from my wrt310N) with the stock PS and my 5a PS and compared signal quality, stability and overall data throughput (IPERF) at the 28Mw setting.

With the 5a ps - I got close to 10% improvement in Snr, less noise as well as the same improvement in overall signal strength.

Under the stock PS - I would see IPERF graphs where my data transfer would drop significantly for a second - I assume retransmissions or signal loss. With the 5a PS - I no longer see this.

I know its hard to believe that Linksys would go cheap on the power supply - but I have seen it with my own eyes...

Bill_MI
Bill In Michigan
MVM
join:2001-01-03
Royal Oak, MI
TP-Link Archer C7
Linksys WRT54GS
Linksys WRT54G v4

Bill_MI

MVM

Hi Dellsweig, I'm not doubting such tests. What I'd like to know is that same improvement may be realized using a better 12V@1A supply, too.

Actually, I'd love to see that test watching voltage level at the router power connector with an oscilloscope. After all... 12V@1A is 12 watts!

dellsweig
Extreme Aerobatics
MVM
join:2003-12-10
Campbell Hall, NY

dellsweig

MVM

said by Bill_MI:

Hi Dellsweig, I'm not doubting such tests. What I'd like to know is that same improvement may be realized using a better 12V@1A supply, too.

Actually, I'd love to see that test watching voltage level at the router power connector with an oscilloscope. After all... 12V@1A is 12 watts!
Someone on the dd-wrt forums used an analogy to audio speakers - where not enough power causes audio distortion - or clipping. I wonder if we are seeing the same here with the radio carrier??

I dont own a oscilliscope so I cant do that kind of analysis but the analogy makes sense

Expand your moderator at work

Bill_MI
Bill In Michigan
MVM
join:2001-01-03
Royal Oak, MI
TP-Link Archer C7
Linksys WRT54GS
Linksys WRT54G v4

2 edits

Bill_MI to dellsweig

MVM

to dellsweig

Re: Undersized Power supplies from Linksys.

That's not a bad analogy. I don't know what the current demand looks on these routers but under-powered power supplies will coincide current demand with voltage dips. 12V may dip to 9V if it's really bad. "Distortion" means it's not a solid 12VDC. That's what a scope would easily see.

There's also the possibility the 12V@5A supply you're using is supplying more like 13, 14, 15VDC when lightly loaded - but the performance benefit comes with it. I don't know the power distribution but most modern switching power handlers are pretty tolerant over a large voltage range (it may never blow something but I could never say that fact is assured).

Anyone got a DC meter and can get on that voltage may be telling.

EDIT: Dellsweig, is that power supply "heavy"? The picture tells me is is NOT a linear supply with a heavy transformer but a light one which is surely a switcher type. Most are these days. A properly designed switcher type will often have better regulation, too. What about the original?

IRON = heavy transformer = linear supply
Light = switcher = poor design can cause problems but usually better and surely "green".

thedragonmas
Premium Member
join:2007-12-28
Albany, GA
Netgear R6300 v2
ARRIS SB6180

thedragonmas

Premium Member

said by Bill_MI:

EDIT: Dellsweig, is that power supply "heavy"? The picture tells me is is NOT a linear supply with a heavy transformer but a light one which is surely a switcher type. Most are these days. A properly designed switcher type will often have better regulation, too. What about the original?

IRON = heavy transformer = linear supply
Light = switcher = poor design can cause problems but usually better and surely "green".
i can tell you the ac adapter that came with my wrt54gl weights practically nothing. if my volt meter didnt die on me a few months ago id be glad to give ya numbers.

peter_m
Premium Member
join:2005-07-13
Canada, QC

peter_m

Premium Member

Has anyone tried it on a WRT54GL ?

dellsweig
Extreme Aerobatics
MVM
join:2003-12-10
Campbell Hall, NY

dellsweig

MVM

said by peter_m:

Has anyone tried it on a WRT54GL ?
Just tried my 12V 5A supply on my WRT54GL - G Ap.

Saw a 10% improvement of WLAN to WAN speeds - still not as fast as my WRT310N for the same test.

Saw increase in signal quality and strength - about 10%

During WLAN to LAN IPERF file test - I saw less drops in the graphs - more consistent transfer

I think I will order another one of these for my WRT54GL - nice to see the same type of improvement as I have been seeing with the WRT310N

peter_m
Premium Member
join:2005-07-13
Canada, QC

3 edits

peter_m

Premium Member

Excellent and thank you Dellsweig.
Going from the stock 1 amp to 5 amps sounds a little extreme. Are you able to measure how many amps the WRT54GL is drawing under load?

It might make for a physically smaller and more economical PSU...

Peter

dellsweig
Extreme Aerobatics
MVM
join:2003-12-10
Campbell Hall, NY

dellsweig

MVM

said by peter_m:

Excellent and thank you Dellsweig.
Going from the stock 1 amp to 5 amps sounds a little extreme. Are you able to measure how many amps the WRT54GL is drawing under load?

It might make for a physically smaller and more economical PSU...

Peter
I am strictly making observations on performance - I would not attempt to give you the electrical details.

As for size - the power blocks linksys (and other vendors) supply are a real pain - they generally dont fit on a power strip. The PS I picked up uses a simple yankee cord to the strip. Also - there is no downside to having sufficient power available - thats not to say that a 2a supply would not be fine - this is just what I purchased.
dellsweig

1 edit

dellsweig to peter_m

MVM

to peter_m
said by peter_m:

Excellent and thank you Dellsweig.
Going from the stock 1 amp to 5 amps sounds a little extreme. Are you able to measure how many amps the WRT54GL is drawing under load?

It might make for a physically smaller and more economical PSU...

Peter
Yet another SUCCESS story by upgrading the powersupply

»www.dd-wrt.com/phpBB2/vi ··· start=75

This is such a no-brainer - I wonder why EVERYONE isnt running out and doing this??
dellsweig

dellsweig to peter_m

MVM

to peter_m
said by peter_m:

Excellent and thank you Dellsweig.
Going from the stock 1 amp to 5 amps sounds a little extreme. Are you able to measure how many amps the WRT54GL is drawing under load?

It might make for a physically smaller and more economical PSU...

Peter
Peter

On the dd-wrt forum - power supply thread

»www.dd-wrt.com/phpBB2/vi ··· start=75

There is a graph showing signal and noise at 2A and at 5A

This shows that even 2 amps is not enough

HTH

koitsu
MVM
join:2002-07-16
Mountain View, CA
Humax BGW320-500

koitsu to dellsweig

MVM

to dellsweig
said by dellsweig:

said by peter_m:

Excellent and thank you Dellsweig.
Going from the stock 1 amp to 5 amps sounds a little extreme. Are you able to measure how many amps the WRT54GL is drawing under load?

It might make for a physically smaller and more economical PSU...

Peter
Yet another SUCCESS story by upgrading the powersupply

»www.dd-wrt.com/phpBB2/vi ··· start=75

This is such a no-brainer - I wonder why EVERYONE isnt running out and doing this??
Because not a single person has taken the effort to bring any of this to light with Cisco/Linksys. Until that happens, most customers are going to take this with a grain of salt.

Someone will need to get in touch with the right folks (specifically engineers) at Cisco/Linksys to discuss it, and have something done about it. If there's no response, keep trying other methods of contact.

peter_m
Premium Member
join:2005-07-13
Canada, QC

1 edit

peter_m

Premium Member

said by koitsu:

said by dellsweig:

said by peter_m:

Excellent and thank you Dellsweig.
Going from the stock 1 amp to 5 amps sounds a little extreme. Are you able to measure how many amps the WRT54GL is drawing under load?

It might make for a physically smaller and more economical PSU...

Peter
Yet another SUCCESS story by upgrading the powersupply

»www.dd-wrt.com/phpBB2/vi ··· start=75

This is such a no-brainer - I wonder why EVERYONE isnt running out and doing this??
Because not a single person has taken the effort to bring any of this to light with Cisco/Linksys. Until that happens, most customers are going to take this with a grain of salt.

Someone will need to get in touch with the right folks (specifically engineers) at Cisco/Linksys to discuss it, and have something done about it. If there's no response, keep trying other methods of contact.
Koitsu,
call me pessimistic but I think it would be a waste of time. We are talking about a $59 off the shelf product. Good luck getting an engineer. I think we have more chances of one of them stumbling on this thread and reading it then one of us calling techsupport.

Just my opinion,
Peter

dellsweig
Extreme Aerobatics
MVM
join:2003-12-10
Campbell Hall, NY

2 edits

dellsweig

MVM

said by peter_m:

Koitsu,
call me pessimistic but I think it would be a waste of time. We are talking about a $59 off the shelf product. Good luck getting an engineer. I think we have more chances of one of them stumbling on this thread and reading it then one of us calling techsupport.

Just my opinion,
Peter
I am convinced Cisco KNOWS the PS is an issue.

I have RMA'd a few WRT54G's and one WRT310N over the years. During the phone process with the Indian script reader, one of the tests they have you do EVERYTIME is to ask if you have another power supply and to swap that in to see if it fixes the problem

In fact, the WRT310N I RMA'd went back with a 1A power supply and the new/recond one had a 2A with an RF choke in the power line.

peter_m
Premium Member
join:2005-07-13
Canada, QC

1 recommendation

peter_m

Premium Member

We can only hope they do something about it then.

I have hard time wrapping my head around the 5amp/12v PSU. I see the graphs and believe your data to be genuine. Just that it's 60 watts we're talking about! 60 watts should not be required for a device that doesn't heat up that much...

What could be causing the problem? The regulator inside to the WRT not handling sudden spikes in the power consumption? Power capacitors being too small?

Has anyone considered a 15v 2amp PSU? The internal voltage regulator can probably handle it...

Peter

Bill_MI
Bill In Michigan
MVM
join:2001-01-03
Royal Oak, MI
TP-Link Archer C7
Linksys WRT54GS
Linksys WRT54G v4

1 recommendation

Bill_MI

MVM

Peter, we're thinking the same. It's far more complex than getting down to ampere rating on commodity cut-rate power supplies. But no one is getting a meter on the delivered voltage - I'd wager it's ending up greater than 12VDC.

Someone familiar with the radio module may be able to confirm if it runs directly off the incoming voltage and gets "happier" with more incoming voltage. Transmit power is very "bursty" in nature and I wouldn't doubt there's some "good enough" in the design for handling sharp demand.

Everything else is surely off regulated 3.3V which should never notice such incoming fluctuations - if it does it's really a bad design.

peter_m
Premium Member
join:2005-07-13
Canada, QC

1 edit

1 recommendation

peter_m

Premium Member

said by Bill_MI:

Peter, we're thinking the same.
I'm glad someone understood me... I feel better now. Thanks

Tursiops_G
Technoid
MVM
join:2002-02-06
Brooksville, FL
ARRIS TM1602

1 edit

Tursiops_G

MVM

Just adding a little perspective to this discussion...

Yes, the evidence presented here so far, indicates that the Linksys OEM 1 Amp PS is deficient (and possibly even a 2 Amp unit, as well...)

As to the Actual Cost of the various replacement PSUs available from 12vAdapters.com (Prices are + Shipping and Handling, and are all the Same at $6.99 US, $8.99 CA):
»www.12vadapters.com/categories

1A (Linear): $14.99
1.25A (SMPS): $14.99
2A (SMPS): $16.99
2.5A (SMPS): $16.99
3A (SMPS): $16.99
3.5A (SMPS): $17.99
4A (SMPS): $18.99
5A (SMPS): $19.99
6A (SMPS): $22.99

I Do Agree that the 5A PSU may indeed be a bit of "Overkill", but at THESE prices, Unless someone here decides to try out the 3A-4A PSUs, and post their results to this Forum, the 5A unit is worth the extra $2-3...

-Tursiops_G.

Anonymous_
Anonymous
Premium Member
join:2004-06-21
127.0.0.1

Anonymous_

Premium Member

said by Tursiops_G:

Just adding a little perspective to this discussion...

Yes, the evidence presented here so far, indicates that the Linksys OEM 1 Amp PS is deficient (and possibly even a 2 Amp unit, as well...)

As to the Actual Cost of the various replacement PSUs available from 12vAdapters.com (Prices are + Shipping and Handling, and are all the Same at $6.99 US, $8.99 CA):
»www.12vadapters.com/categories

1A (Linear): $14.99
1.25A (SMPS): $14.99
2A (SMPS): $16.99
2.5A (SMPS): $16.99
3A (SMPS): $16.99
3.5A (SMPS): $17.99
4A (SMPS): $18.99
5A (SMPS): $19.99
6A (SMPS): $22.99

I Do Agree that the 5A PSU may indeed be a bit of "Overkill", but at THESE prices, Unless someone here decides to try out the 3A-4A PSUs, and post their results to this Forum, the 5A unit is worth the extra $2-3...

-Tursiops_G.
UM why not power it with the computer i have done this before

with my linksys wrt54g v 1.0 25amps of power that it can use

dellsweig
Extreme Aerobatics
MVM
join:2003-12-10
Campbell Hall, NY

dellsweig

MVM

no reason why you cant use the PS from your PC - as long as you dont exceed the 12V number.

The bottom line here

the stock PS that comes with the Linksys and other vendors is too small and most likely is causeing many of the issues (signal loss, reboots, bad signal, etc) seen in this and other forums.

A CHEAP and simple solution is to replace it with a PS that has the resources to correctly power your router.

Tursiops_G
Technoid
MVM
join:2002-02-06
Brooksville, FL
ARRIS TM1602

1 edit

Tursiops_G to Anonymous_

MVM

to Anonymous_
Powering it from the PC's PSU is another option (provided that your PSU isn't already being loaded close to the Max, that is.)

The Downside of doing so, is that the "Source" PC MUST be powered-up 24/7 in order to provide +12v to the Router... A bit of a hassle when you may only want to connect Wirelessly via a Laptop/PDA/Game, etc., or from a Different (wired) PC elsewhere on the LAN...

-Tursiops_G.

Anonymous_
Anonymous
Premium Member
join:2004-06-21
127.0.0.1

1 edit

Anonymous_

Premium Member

said by Tursiops_G:

Powering it from the PC's PSU is another option (provided that your PSU isn't already being loaded close to the Max, that is.)

The Downside of doing so, is that the "Source" PC MUST be powered-up 24/7 in order to provide +12v to the Router... A bit of a hassle when you may only want to connect Wirelessly via a Laptop/PDA/Game, etc., or from a Different (wired) PC elsewhere on the LAN...

-Tursiops_G.
nah i would just get a used PSU(wall wart type) at the local thrift shop they have a huge selection
upto 36volt DC/AC