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Topic: Robot Electrical Question (Read 1 time) previous topic - next topic

AKSoapy29


I've got a Netgear 614 router that has 12v @ 1a as it input power specification. Its power supply output (probably a switching unit)  is rated at 12v @ 1a. The power supply measured unloaded output is 14.75v, so I figure the router is voltage tolerant for at least 14.75v supply voltage.   


Mine is a bit different. I think I might try opening it up somehow to see if I can find a regulator on the board. The model of the router I am using: Buffalo WHR-G300N V2.
Andrew K.

AKSoapy29

Nice one Buffalo... I would have never thought there would be Torx screws under the bumpers. Unfortunately, I don't have a Torx that small, so I will see if I and use a Philips and a rubber band or something. Maybe flat.
Andrew K.

AKSoapy29

#32
Jun 14, 2013, 10:45 pm Last Edit: Jun 14, 2013, 10:49 pm by AKSoapy29 Reason: 1
These are my findings, and it doesn't look like there is any internal regulator. I think there might be a couple for the antennas, but then again, they could be transistors.


Andrew K.

cr0sh

Well - I can see one voltage regulator - VR1 - but what it's for or such, who knows (well, you have the board, so you could find out). What's actually more interesting to me is U14 - that whole section around it appears to be the main power supply "nexus" if you will. Finding out what that IC is and what it supplies would be very useful/helpful. Also - measuring the voltage after those 0 ohm resistors/jumpers just southwest of U14 would also be interesting; it appears to be the main positive rail for the entire board. Likely, the positive "rail" is the plane on the top, and the negative/ground rail is the plane on the other side of the PCB (just guessing, though). Basically the fat light green areas are large "filled" traces meant to act as an RF reduction purpose. Likely, VR1 taps off of this. I would suspect that U14 outputs something lower than 12 volts, and VR1 takes that, and likely reduces it further. Maybe U14 outputs 5 volts, and VR1 takes it to 3.3 volts - or U14 outputs 3.3 volts and VR1 takes it to something even lower. Finding information on the other chips, datasheets and such - can help you figure this out more.
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AKSoapy29


Well - I can see one voltage regulator - VR1 - but what it's for or such, who knows (well, you have the board, so you could find out). What's actually more interesting to me is U14 - that whole section around it appears to be the main power supply "nexus" if you will. Finding out what that IC is and what it supplies would be very useful/helpful. Also - measuring the voltage after those 0 ohm resistors/jumpers just southwest of U14 would also be interesting; it appears to be the main positive rail for the entire board. Likely, the positive "rail" is the plane on the top, and the negative/ground rail is the plane on the other side of the PCB (just guessing, though). Basically the fat light green areas are large "filled" traces meant to act as an RF reduction purpose. Likely, VR1 taps off of this. I would suspect that U14 outputs something lower than 12 volts, and VR1 takes that, and likely reduces it further. Maybe U14 outputs 5 volts, and VR1 takes it to 3.3 volts - or U14 outputs 3.3 volts and VR1 takes it to something even lower. Finding information on the other chips, datasheets and such - can help you figure this out more.


Heh, took me a while to decipher your post, but I understand now. I am just guessing here, but those 'jumpers' you mentioned south-west of U14, I think those might be fuses. VR1 probably regulates power for the antennas, or the leds and other circuitry on the board. Looking at the photo, L19 and L62 (top left) could also be fuses; it looks like they are coming from the main power jack.

Unfortunately, I resealed the router, and it would take a heck of a lot of work and some new screwdriver bits to open it again.
Andrew K.

zoomkat

The VR1 leads could be checked for continuity between the + and - inputs on the power in jack. If there is a connection with the power input jack, with the unit powered up, the output voltage of VR1 could be measured. A part number from VR1 might also determine the max allowed input voltage. Harbor Freight has inexpensive torx/security bits, which come in handy if you are a fix-it person.
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