WRT54GL lower voltage?

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filo4u
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Joined: 14 Nov 2009
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PostPosted: Sat Nov 14, 2009 18:29    Post subject: WRT54GL lower voltage? Reply with quote
hey guys i have a WRT54GL i added a fan and my problem is that the fan is to loud i want to lower voltage to lower rpm.. the fan will run on 9v i tested and it with a 9v batt is there anyway i could do this? thanks in advance.. i saw a video on youtube but can't find it anymore he lowered his fan voltage by adding LEDs.. any help would be great!! Smile

Someone told me that a 3 ohm 10 watt resistor should do the trick so i went and got one.. i tested the voltage after installing resistor and i still get 12v.. do i have the wrong resistor? WRT54GL power rating is 12v 1a right?
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robert-e
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Joined: 19 Feb 2007
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PostPosted: Sun Nov 15, 2009 21:44    Post subject: Reply with quote
The 3 ohm resister could drop the voltage depending on the current draw of the fan, but ONLY with the fan connected. A better solution is to use a 9 volt positive voltage regular chip (eg. 7809, or a 7808 with a diode in the ground lead if a 9 volt reg. is not available). Connect the input lead to the router + 12 volts, the center to ground, and the output to the fan positive input lead. A standard 78xx series will handle an amp of current.
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Bob
HardReset
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PostPosted: Mon Nov 16, 2009 15:44    Post subject: Reply with quote
Instead of buying resisters, voltage regulators, etc...

Go purchase a nice quiet 12V fan.

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filo4u
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PostPosted: Wed Nov 18, 2009 8:54    Post subject: Reply with quote
i did try to look for a nice quiet 12V fan no luck.. i was browsing around youtube and i saw a trick to lower voltage what it said to do was to connect the negative wire to a 3v positive source in the router.. it worked!! my only question is.. is this safe? I've been running it for 2 days now seems to work..
redhawk0
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PostPosted: Wed Nov 18, 2009 13:06    Post subject: Reply with quote
filo4u wrote:
i did try to look for a nice quiet 12V fan no luck.. i was browsing around youtube and i saw a trick to lower voltage what it said to do was to connect the negative wire to a 3v positive source in the router.. it worked!! my only question is.. is this safe? I've been running it for 2 days now seems to work..


Yeah...you can do that...it essentially now has 8.7V running the fan....as long as the fan never shorts out...you can run like this.

redhawk

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filo4u
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Joined: 14 Nov 2009
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PostPosted: Fri Nov 20, 2009 7:14    Post subject: Reply with quote
redhawk0 wrote:
Yeah...you can do that...it essentially now has 8.7V running the fan....as long as the fan never shorts out...you can run like this.

redhawk


Thanks so much redhawk0 for your reply.. i went to my local electronic store and asked if this was safe they said as long as its a true flow or real flow power adapter something like that it should be okay if not it will soon break the power adapter.. is this true?
PedroDaGr8
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Joined: 29 Nov 2006
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PostPosted: Thu Dec 03, 2009 22:54    Post subject: Reply with quote
Aren't fans typically pretty noisy (electrically) on a DC line? Maybe I am confusing them with AC fans. Though I would wonder if the 12/3V method wouldn't introduce some noise.

That being said, these damn things NEED a fan. My WRT54GS w/ heatsinks and fans has not crashed even ONCE in the past few years. It only goes down with power outages or firmware updates
ecknight6754
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Joined: 04 Dec 2009
Posts: 7

PostPosted: Sat Dec 05, 2009 0:08    Post subject: Reply with quote
just install a pot on the pos line and that way you could adjust the rpm to whatever you wanted it to be
redhawk0
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Joined: 04 Jan 2007
Posts: 10908
Location: Wherever the wind blows- North America

PostPosted: Sun Dec 06, 2009 13:29    Post subject: Reply with quote
I agree...a potentiometer control would be best...and it can be made very cheaply (and effectively) with only 2 components. Check this out.

http://www.overclockers.com/small-and-simple-fan-voltage-regulator/

redhawk

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I currently test dd-wrt on Asus, Buffalo, Linksys, and Netgear. Too many to list.

Looking for more test units (newer models) for the project...got a brick?...PM me to make a donation. (USA) A donation is not a debricking service....it is a way to "Give back" to the dd-wrt project.

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redhawk0
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Joined: 04 Jan 2007
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Location: Wherever the wind blows- North America

PostPosted: Fri Jan 08, 2010 19:54    Post subject: Reply with quote
Well...I just received a donated WRT310N unit that had a botched fan/antenna job on it....After much soldering and testing, I have the unit working.

But...what I wanted to say here is that it had a fan installed but hotwired directly to the power connector inside the unit....I build one of the little circuits that I linked to in the last post...except I used a 25K pot and a 2N3904 NPN transistor instead of what was called out in that thread. (its what I had laying around) The 2N3904 can only handle 200mA but that isn't a problem for an 80mm Fan that draws 160mA max...so it works just fine. I used a hot "frog sticker" to poke holes in the top of the case where the leads for the Pot and the Transistor goes...and soldered directly under the lid of the unit....so its really easy to adjust the fan speed with the pot mounted external.

This unit is super quite...almost like there is no fan at all. (BTW...I cut the fan LED lines...I hate all that extra light if this unit would end up in my bedroom)

redhawk

_________________
I currently test dd-wrt on Asus, Buffalo, Linksys, and Netgear. Too many to list.

Looking for more test units (newer models) for the project...got a brick?...PM me to make a donation. (USA) A donation is not a debricking service....it is a way to "Give back" to the dd-wrt project.

I do NOT provide personal assistance through chat or phone....so please don't ask.
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