Which WRT54G Power Supply?

I have two WRT54G power supplies, both are 12vdc and .5A. One is
the traditional wire-wrapped transformer (from the WRT54G V5.0)
and the newer one that comes with V8.0 is about half the size and
1/10th the weight - not a traditional power supply/adapter.

I need to return one unit to the store so I have my choice of
adapters. Which one should I keep?

-sw


Steve Wertz

Steve Wertz <(E-Mail Removed)> hath wroth:

>I have two WRT54G power supplies, both are 12vdc and .5A. One is
>the traditional wire-wrapped transformer (from the WRT54G V5.0)
>and the newer one that comes with V8.0 is about half the size and
>1/10th the weight - not a traditional power supply/adapter.
>
>I need to return one unit to the store so I have my choice of
>adapters. Which one should I keep?

I think (not sure) that Linksys started shipping the smaller (and more
efficient) switching power supplies with the WRT54G v6. Either
adapter will work, but the smaller switcher is far more efficient.
Just put your hand on the power supply when running and notice the
difference in how hot it gets. However, ethics require that you
return the unit you bought with whatever was originally supplied.
Swapping power supplies is not returning products in their original
sellable condition.


--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

"Jeff Liebermann" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Steve Wertz <(E-Mail Removed)> hath wroth:
>
>>I have two WRT54G power supplies, both are 12vdc and .5A. One is
>>the traditional wire-wrapped transformer (from the WRT54G V5.0)
>>and the newer one that comes with V8.0 is about half the size and
>>1/10th the weight - not a traditional power supply/adapter.
>>
>>I need to return one unit to the store so I have my choice of
>>adapters. Which one should I keep?
>
> I think (not sure) that Linksys started shipping the smaller (and more
> efficient) switching power supplies with the WRT54G v6. Either
> adapter will work, but the smaller switcher is far more efficient.
> Just put your hand on the power supply when running and notice the
> difference in how hot it gets. However, ethics require that you
> return the unit you bought with whatever was originally supplied.
> Swapping power supplies is not returning products in their original
> sellable condition.
>
>
I seem to recall that when I had a switcher on my Dell laptop
that there was some interference on the local TV,
while changing back to a traditional xformer caused no TV interference...

On Tue, 11 Sep 2007 20:15:11 -0700, Jeff Liebermann wrote:

> I think (not sure) that Linksys started shipping the smaller (and more
> efficient) switching power supplies with the WRT54G v6. Either
> adapter will work, but the smaller switcher is far more efficient.

OK. I thought maybe they just down-sized due to copper prices
and this new one would be less reliable.

> However, ethics require that you
> return the unit you bought with whatever was originally supplied.
> Swapping power supplies is not returning products in their original
> sellable condition.

Ethics would also dictate that Linksys should exchange a
defective product (known issue with that model) that was bought
1.5 years ago, but only unwrapped and taken out of the box and
used 2 weeks ago. Granted, they probably can't tell how long
it's been in actual use.

Thanks for the PS info, Jeff.

-sw

Steve Wertz <(E-Mail Removed)> hath wroth:

>On Tue, 11 Sep 2007 20:15:11 -0700, Jeff Liebermann wrote:
>
>> I think (not sure) that Linksys started shipping the smaller (and more
>> efficient) switching power supplies with the WRT54G v6. Either
>> adapter will work, but the smaller switcher is far more efficient.

>OK. I thought maybe they just down-sized due to copper prices
>and this new one would be less reliable.

Nope. Just efficiency. The cell phone crowd has gone to switchers
for at least 7 years. One nice feature is that they turn totally off
when there's no load. They also turn off when overloaded or shorted.
The rising cost of copper is a fairly recent phenomenon.

I've had more failures on the xformer variety than the switchers. The
problem with the xformer types is that they get hot, especially if
overloaded. They're required to have a thermal fuse inside. Get it
hot enough, and the fuse blows, permanently. In general, the hotter
it gets, the faster if fails.

>> However, ethics require that you
>> return the unit you bought with whatever was originally supplied.
>> Swapping power supplies is not returning products in their original
>> sellable condition.

>Ethics would also dictate that Linksys should exchange a
>defective product (known issue with that model) that was bought
>1.5 years ago, but only unwrapped and taken out of the box and
>used 2 weeks ago. Granted, they probably can't tell how long
>it's been in actual use.

What known issue? Punch and hold reset for over 30 seconds. Upload
latest firmware. Try again.

>Thanks for the PS info, Jeff.

--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

"P.Schuman" <(E-Mail Removed)> hath wroth:

>I seem to recall that when I had a switcher on my Dell laptop
>that there was some interference on the local TV,
>while changing back to a traditional xformer caused no TV interference...

Yep. Your unspecified model Dell laptop power supply probably is
running at 60 watts. If it were 95% efficient, it would still belch 3
watts of heat and RF (mostly heat). Meanwhile, the Linksys switcher
runs at perhaps 6 watts. At 95% efficiency, that's only 0.3 watts of
heat and RF or 10 times less. It's also more difficult to reduce RFI
from bigger power supplies. The Linksys power supply might make some
noise, but it will probably be 1/10th of the Dell power supply.

I do some ham radio at home. Listening on the various HF bands
(3-30MHz), I can hear LOTS of RFI junk from various electronics around
the house. Wall warts were a major problem until I butchered a power
strip by adding ferrite beads on the power wires, and bypass
capacitors. Most of the RFI from the wall warts was from conducted
radiation. (Conductors radiate. Components do not). Within reach, I
see 5 different switcher type wall warts, with no associated RFI.
Incidentally, the worst RF noise makers in my house are the La Cross
WS-9520-U weather station, DirecTV DVR, and various computers around
the house. However, the ultimate RF noise maker is my neighbors giant
plasma TV.

--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Tue, 11 Sep 2007 22:22:18 -0700, Jeff Liebermann wrote:

> Steve Wertz <(E-Mail Removed)> hath wroth:
>
>>Ethics would also dictate that Linksys should exchange a
>>defective product (known issue with that model) that was bought
>>1.5 years ago, but only unwrapped and taken out of the box and
>>used 2 weeks ago. Granted, they probably can't tell how long
>>it's been in actual use.
>
> What known issue? Punch and hold reset for over 30 seconds. Upload
> latest firmware. Try again.

This was overheating (or something) under heavy load. It would
last 36-48 hours at a time, then die. All the LED's made it look
like it was still working, but the router was in outer space
somewhere. So I threw a copper heat-sink on the Broadcom chip
and that extended it's MTBF to 5-6 days at a time, but it still
croaked regularly. It was not over-clocked or anything. Several
sites mention that this runs too hot, overclocked or not.

It wasn't the PS, either. Unplugging it at the back of the unit
for 5 minutes, it would last another 30 minutes. Unplug it for 4
hours, it would last another couple days. Latest firmware was
installed after the first failure - same symptoms.

-sw