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liz
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Re: Power supply news!

Thu Oct 20, 2011 9:24 pm

Head to the front page, where Eben has put up a splendidly technical new blog post. (Hint - it\'s 5V micro USB.)
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dhb
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Re: Power supply news!

Thu Oct 20, 2011 9:34 pm

Yeah! My first choice, those are all over here in the U.S. these days. I\'m just glad they\'ll become common enough they work for your primary market too.

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liz
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Re: Power supply news!

Thu Oct 20, 2011 9:38 pm

Exactly - ubiquity was probably the biggest part of the decision for us, and the move to standardisation in mobile phones has helped us out a lot here; we don\'t want people to be spending unnecessary money on power supplies when they may well already have one in the house.
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Bacan
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Re: Power supply news!

Thu Oct 20, 2011 9:39 pm

I\'m happy also a good widely available choice was found and selected.

Now to recycle all those assorted wall-warts I have sitting in a banker\'s box in my garage.

kme
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Re: Power supply news!

Thu Oct 20, 2011 9:39 pm

YES! Brilliant decision.

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liz
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Re: Power supply news!

Thu Oct 20, 2011 9:47 pm

I should add as a smarmy aside here: this sort of thing is what\'s taking all the time a lot of you guys have been complaining about, and is the sort of reason we\'ve not been able to show you artwork yet. Every component on the board has had a deal of spreadsheetery and argument applied to it - up-front cost isn\'t the only vector we have to calculate; there are questions about longevity, ubiquity (if this had been a few years ago we might even have ended up with the old Nokia-type chargers - which in the long run would have been a disaster) and accessibility. I\'m with you guys: I think this is absolutely the right decision, and I\'m really pleased about it.
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emercer
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Re: Power supply news!

Thu Oct 20, 2011 9:49 pm

Kudos on the very smart decision!

SlayingDragons
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Re: Power supply news!

Thu Oct 20, 2011 10:02 pm

Awesome, very good decision. ^_^

obarthelemy
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Re: Power supply news!

Thu Oct 20, 2011 10:04 pm

Yes ! Thank you first or unveiling that answer for all the hardware modders, and second for choosing micro-USB, which we can easily get from an existing phone charger (or cheaply buy a new one), or from a powered USB hub by adding an extra upwards hub -> pi power cable beside the downstream, pi -> hub data one.
Plus since it\'s cheaper to produce, now you can put in extra RAM </ducks>

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liz
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Re: Power supply news!

Thu Oct 20, 2011 10:11 pm

Yeah - I was aware some of you hardware hacker types were getting desperate for the info, so asked the guys if they could push this news out ahead of the artwork, which they did after only a minimum of grumbling. I am keeping a thumb over the bit of the screen where you mention RAM. 8)
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Johannes
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Re: Power supply news!

Thu Oct 20, 2011 10:18 pm

This puts a big damper on the hopes of many people who envisioned \"alternatively powered\" applications. Any battery / solar / dynamo / PoE powered system will need an external voltage regulator now and flaws in that part will not only lead to fried Raspberry Pis but also fried peripherals as the voltage is passed through. I suppose there won\'t be a polarity protection diode either? IMHO the wide input voltage range was an enticing hardware feature. I\'m sad to see it go.

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liz
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Re: Power supply news!

Thu Oct 20, 2011 10:20 pm

There is a polarity protection diode. There\'s a voltage clamp, and there\'s a self-resetting semiconductor fuse. We do think about these things!
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ffuentes
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Re: Power supply news!

Thu Oct 20, 2011 10:22 pm

If I want to buy the AC adaptor, could I buy it with the R-PI?

I have one but it only have 300mA

EWH
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Re: Power supply news!

Thu Oct 20, 2011 10:23 pm

Excellent decision. Most people will be able to find a micro-USB adapter, either in hand or cheaply. Or they can combine the expense of a powered USB hub and an AC adapter for the Pi with just a USB / micro-USB cable needed to serve as the power supply for the RP instead of yet another wall wart - and that cable will work to power the RP from any USB host, too. Well done.

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liz
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Re: Power supply news!

Thu Oct 20, 2011 10:24 pm

We\'ll be selling adaptors from the website for people who don\'t have one already.
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Johannes
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Re: Power supply news!

Thu Oct 20, 2011 10:24 pm

Thanks for the clarification. I was misled by this: \"Unlike coaxial jacks, we know that we’ll be receiving 5V over this connector, which we can pass on unregulated to HDMI and USB devices.\"

rmike
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Re: Power supply news!

Thu Oct 20, 2011 10:54 pm

Hi,
[quote]There\'s a voltage clamp, and there\'s a self-resetting semiconductor fuse. We do think about these things![/quote] what about voltage tolerances? I have seen usb chargers from 4.8V - 5.5V. Not to mention cheap car usb adapters without proper filtering and spike cutting. What voltage will do harm? (absolute ratings?)

Michael

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liz
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Re: Power supply news!

Thu Oct 20, 2011 10:59 pm

Good question. We\'ll need to test for that - it\'s one of the reasons we\'re building prototypes!
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SlayingDragons
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Re: Power supply news!

Thu Oct 20, 2011 11:04 pm

[quote]Quote from liz on October 20, 2011, 23:59
Good question. We\'ll need to test for that - it\'s one of the reasons we\'re building prototypes![/quote]

Oh, I thought it was to keep us writing in anxiety waiting for it to come out while you guys get to mess with it. :P

kme
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Re: Power supply news!

Fri Oct 21, 2011 12:01 am

[quote]Quote from ffuentes on October 20, 2011, 23:22
If I want to buy the AC adaptor, could I buy it with the R-PI?

I have one but it only have 300mA[/quote]300 mA will be plenty for the A model, and probably enough for the B model too. Remember the USB ports are not powered so they don\'t use much. But it\'s a tight fit, agreed.

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Re: Power supply news!

Fri Oct 21, 2011 2:38 am

It is nice a decision has been made for the power. I still believe the 6 to 20v option was much more flexible and easier to find power supplies for here in the U.S. At least I can now get moving forward. I have had a 7805 ready as I felt it would probably go this way. That is a micro-B USB plug. I have my doubts about the durability of that connector for extended use outside of a case. That was one of the key points that was mentioned throughout discussions of why you used full sized USB \"A\" connectors.

Sorry not trying to go trolling but that is my honest opinion. Just get the dang thang into production and it will all be ok in the world.

Well time to go looking for a cable to hack up. Guess I\'ll be hitting radioshack to get a PCB to build a power board for the router. 12v to the router then I will just cut off the barrel connector I already had soldered in. Put those wires to a 7805 then check and make sure I am getting 5v and not more. This will give me up to 1.5amps at 5v or enough to power two RasPi\'s. I have a small heatsink for the 7805 I can steal from a burned out wall wart. Then I will have to see where I can place it out of the way in the router case.
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Re: Power supply news!

Fri Oct 21, 2011 2:45 am

@rmike a very good point!
I will have to make sure my power board is very close to 5v!
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bnolsen
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Re: Power supply news!

Fri Oct 21, 2011 2:47 am

I couldn\'t find it with a quick internet search but someone is selling a doubly reinforced PCB microusb connector. That may be a little more expensive but you should definitely consider using theirs. Breaking the connector itself may be a concern.

I\'ll continue to look for the link.

Found a reference here:

http://www.smk.co.jp/news/press_release/2011/934cs/

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Gert van Loo
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Re: Power supply news!

Fri Oct 21, 2011 7:50 am

Using linear regulators means the device will use more then the originally promised one watt. (Sorry but the price promise is what we really had to keep). I have written a document to explain why for the non-electronic engineers subscribers.
http://www.scribd.com/doc/69700160/Rasp ... More-Power

obarthelemy
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Re: Power supply news!

Fri Oct 21, 2011 8:26 am

Thanks for the warning.

obvious question is obvious: how much power does the Pi use now ?

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