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16  Using Arduino / General Electronics / Re: Bridge Rectifier on: June 24, 2013, 04:35:07 pm
Looking at the circuit board, the diodes were used as a bridge rectifier. What the board was used for, I don't know. It looks like it has 18VAC going through a 5A fuse before it goes in to the rectifier.
17  Using Arduino / General Electronics / Re: Bridge Rectifier on: June 24, 2013, 04:27:14 pm
Looking up the part number of the diode, it looks to be a low forward voltage (Less voltage loss is how I understand it (0.48V loss to be exact)) and it looks like it should work. I think the board I took it from was actually using it as a bridge rectifier, but I'll have to check on that.
18  Using Arduino / General Electronics / Re: Bridge Rectifier on: June 24, 2013, 04:18:36 pm
Looking at my power supply/transformer, here are the specs: Primary: 120VAC 60Hz 50W, Secondary: 24VAC 40VA. VA, is that just Amps? My load it 0.125A - 0.350A @ 24VDC.
19  Using Arduino / General Electronics / Bridge Rectifier on: June 24, 2013, 03:52:49 pm
Hi. I need to convert AC to DC, and I was thinking of using a bridge rectifier using four diodes. I was wondering if there should be any way to approach this. I have four diodes, V 90SQ045, which I pulled from an old circuit board, and I also have a 22000μF capacitor I pulled from the same board, and I was going to add that smooth the DC output. The leads on the diodes arn't that big, +/- 1/2inch, so can I just solder them together?

I know what AC is and how it works, but I haven't worked with it before, so I appreciate any help.
20  Using Arduino / General Electronics / Re: Robot Electrical Question on: June 15, 2013, 08:39:54 pm
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.
21  Using Arduino / General Electronics / Re: Robot Electrical Question on: June 14, 2013, 03:45:22 pm
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.


22  Using Arduino / General Electronics / Re: Robot Electrical Question on: June 14, 2013, 03:26:47 pm
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.
23  Using Arduino / General Electronics / Re: Robot Electrical Question on: June 14, 2013, 03:19:39 pm
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.
24  Using Arduino / General Electronics / Re: Robot Electrical Question on: June 14, 2013, 02:00:18 pm
I just metered the power supply it came with, and it is outputting 12.28 volts, so I am preassuming the router is getting power from a pre-regulated power source. I could go with the 12 batteries to make things simple.  A long time ago, I remember picking up some 12 volt regulators from Radioshack. I could probably go a couple batteries over and use that, but I would have to find a heatsink that wouldn't melt the plastic I am mounting everything to.
25  Using Arduino / General Electronics / Re: Robot Electrical Question on: June 13, 2013, 09:57:14 pm
The NiMH AA-cells bought at Walmart et al are typically 2000-2500 mAH is for the single
cell.
Alright, I was just making sure.

Wire 10 in series, and you have 12V good for 2000+ mAH.
1.5V * 10 is 15 volts. You would need 8 1.5V batteries (AA) to power the router.

I think I will buy some of these batteries and hook them up to the robot.
26  Using Arduino / General Electronics / Re: Robot Electrical Question on: June 13, 2013, 07:41:03 pm
Alright. Looking at these, they say the cells are 2000mAh. Does anyone know if that is 2000mAh each, or total?
27  Using Arduino / General Electronics / Re: Robot Electrical Question on: June 13, 2013, 06:52:47 pm
My dad thought of another way to power the router. He was thinking I could use those rechargable AA batteries. I found some, but the specs arn't that good. It says 2050mAh, but I don't know if that is for all of them combined, or each cell. That would be for these. There are also these, but they provide lower mAh. Again I don't know if the power is combine or for each cell.
28  Using Arduino / General Electronics / Re: Robot Electrical Question on: June 06, 2013, 10:52:05 pm
Are the 7.2v batteries susceptible to damage if discharged too low?

My dad just brought up that point with me. One of the batteries is going to drain really fast. Is there any way to run them in parallel to the Vex PIC, and in series to the wifi router, at the same time? I would think you can using a few diodes.
29  Using Arduino / General Electronics / Re: Robot Electrical Question on: June 06, 2013, 10:17:40 pm
Personally, I think LarryD's suggestion is the best; you gain the low weight you are seeking, and can easily center-tap the battery to get your 7.2v output for whatever else you are running. Dropping the 14.4v down to 12v @ 1A isn't very problematic - you can easily find a DC to DC converter to do that. Or - have you tried running the router off 7.2 VDC? It might just work...

Whoops, looks like I posted as that post went up. Yeah, that sounds better; more powerful, easier, and lighter. I think I could throw $30 in to another battery, since I already have the charger and they are nice batteries for robots.
30  Using Arduino / General Electronics / Re: Robot Electrical Question on: June 06, 2013, 07:22:16 pm
Adjustable with mounting holes; kind of a neat idea. Does it need a fan?
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