Montare uno slot usb.

[djscandi]

Ciao, ho un netgear dg834gt e ho scoperto che sulla sua scheda è possibile saldare nell'apposito spazio uno slot usb.
Ho trovato una guida molto utile ma purtroppo non riesco a capirla molto bene.
Potreste aiutarmi con dei consigli o suggerimenti? grazie

http://wiki.openwrt.org/oldwiki/open...etgear/dg834gt


ecco comunque cosa scrivono
USB PORT

There is an unpopulated USB port near right from reset button.

If you want to use it you need to solder the USB connector and the following parts:

C515 Polarized capacitor, 470 uF
C516 Capacitor 100nF size: 0805
FB1 Resistor 0 Ohm size: 0805
C124 Capacitor 100nF size: 1210
U102 5 Volt voltage regulator SOT-223 package

Warning!Be careful with the voltage regulator! If you want to use an USB device which is powered from the USB port (usb stick, webcamera, etc.), you should not use SOT-223 package regulator, because it could not dissipate the amount of power.

Let's calculate. The input voltage is 12 Volt (or a bit more) the output is 5 Volt. So the regulator will dissipate (12-5)*current power. For example my webcam need 100 mA power according to it's description. So the regulator in my case will dissipate 7 V *0,1A = 0,7 W power. This amount of power cannot be handled by an SOT-223 package. Regulators in TO-220 package will do it better. The best choice is a small switching mode DC-DC converter.



Unfortunatelly there are some hardly solderable 0402 size parts are missing too. attachment:usb.png

R515, R514 between 16 and 44 Ohm
R516, R517 15 KOhm
C511, C512 47 or 50 pF