Components for powering stand alone Arduberry (1 missing?)


#1

I noticed in the stand alone power Arduberry page that there is a list of 4 components but in the photo there are 5. There appears to be a second “barrel” capacitor in the photo, the smaller one below the large one. The components list does not address this capacitor.

Can someone please tell me what the value is for that capacitor and or why it’s in the photo but not on the list?

I have the other components but without knowing what is necessary for that unidentified component, I can not complete the power regulation build.

TIA


#2

Hey,
Sorry we missed that part, it is a 120uF capacitor, you can use something like this http://www.mouser.com/ProductDetail/Panasonic/EEU-FR1H121LB/?qs=sGAEpiMZZMukHu%2bjC5l7YdvGqII3s6AM6j0YrhqH6Jo%3D. Just make sure that it is rated for 20V or more, just to be safe.

-Karan


#3

Thanks again Karan! You Rock!

I might have one of those in my supplies. I’ve been taking advantage of the Radio Shack store closings. The stores that are closing sometimes get up to 90% off which is when I bought many of my “pins and wires” getting them for pennies on the dollar.

The first phase of that closing of 1000+ stores is complete but there is a second phase of 361 stores closing nation wide and they are at about the 60% off at the moment so I recommend folks here check their local Radio Shacks if they are interested in components and/or Make:It type stuff, robotics, power supplies, soldering gear, etc. Some of the prices are hard to beat and will get even cheaper as the stores get closer to closing.

Thanks again!


#4

I have a 100uF at 35WVDC. That would be ok wouldn’t it? I’m no electrical engineer, just an IT sys admin so I’m still learning. :slight_smile:


#5

Hey,
100uF at 35V should be good enough.

-Karan


#6

Well I ended up buying the 0.1uF ceramic capacitor on your parts list. There is a couple of gotchas.

The recommended part# for that unit will get you probably the smallest solderable part you have ever seen. It’s litterly the size of the head of a pin or smaller.

So I would recommend a larger unit with a similar compatible value. Even with a magnifying glass it’s difficult or next to impossible unless you have a nano-bot that you can train to hold the part in place. Hahaha.
It’s about the size of a 1/8th grain of rice.

Another tip for those wanting to make the Arduberry power circuit with the Dexter recommended parts list should also keep in mind that the resettable fuse part is vulnerable to moisture. You have to use the part within 600+ hours after opening the package because it will “expire.” Baking the part is recommended by Mouser in some cases.

This has been a fun learning experience and helping me to hone by soldering skills. I would recommend that the parts list be updated to reflect a larger more manageable part like possibly a 0.22uf…which I’m about to order in hopes that it is bigger than the current listed part.

Thanks again Karan!


#7

Hey Dex13,
Thanks a lot for the feedback. Sorry for the trboubles that you had when soldering the capacitor. That part is a 0603 footprint and are a pain to solder without a hot air rework station, tweezers help a lot too but yeah, it might be overwhelming for a lot of folks out there. We’ll keep this in mind for the next iteration and change it. You should also check out the 0402 package (http://en.wikipedia.org/wiki/Surface-mount_technology), those things are the hardest to solder.

-Karan


#8

Wow, didn’t think they could get any smaller. A 402 must be like trying to solder a grain of sand to a PCB.
I realize robots normally perform that task with such small components.

After soldering that part it makes everything else seem trivial. I’ve thought about putting an equal value round ceramic button cap instead.

It’s really amazing how tiny they’ve created SMD parts.
My solder job for those pads were pretty sloppy but I’m hoping it at least works.

Thanks Karan!


#9

Karan, since this is just a noise filtering capacitor, can we safely assume that we can increase or decrease it’s value to decrease the AC ripple in our output. I haven’t tried changing the value yet but since I have 150mV AC ripple, I think I’ll have to play around with a few components. Could you please confirm if changing the value of this capacitor would reduce the AC ripple or not? In case it won’t, it’ll be a life saver if you tell me which specific components could impact on the output AC ripple.

Regards,
Dave J
http://blog.7pcb.com


#10

hey mercimek, I wanted to hop in here. Out of curiosity, you have a 150 mV AC ripple; are you sure it’s an AC ripple? Are you powering the board with 120V AC or 220V AC? Or is it a DC ripple?

I’m curious about how you’re able to see that I guess. Are you using a O scope or multimeter?


#11

I have ordered the parts to add stand-alone power to my Arduberry. Taking a closer look at the circuit board, don’t you also need to modify J2? As best I can tell, this jumper chooses between power from the USB and power from the regulator, and as shipped it only selects power from the USB. I suppose I could just close both paths and be careful never to have two power sources connected at the same time, but perhaps a better choice for the next iteration would be to put a Schottky diode in line with the power from the USB and eliminate the jumper. Either that or add header pins so the user can easily change the jumper. Thoughts?


#12

Hi bratoff,
You are spot on with J2. Is selects either USB power or from the DC jack. So you can just connect all 3 and make sure you only use one at a time, or just stick to DC power if you want that. Soldering a header to it might be a bit difficult.

-Karan