Gustavo_Murta
Posts: 24
Joined: Thu Dec 20, 2012 10:04 am
Location: Brasil

Re: Battery Power and USB WiFi?

Mon Feb 11, 2013 10:47 am

Raspberry Pi use low dropout regulators (chinese) to achieve 3,3V and 1,8V from 5V power source.

5V to 3,3V LDO regulator (REG 2) : SE8117T33

5V to 1,8V LDO regulator (REG 1) : SE8117T18

http://pdf.dzsc.com/SE8/SE8117.pdf

Gustavo Murta (Brazil)

photomankc
Posts: 80
Joined: Fri Aug 24, 2012 12:58 pm

Re: Battery Power and USB WiFi?

Mon Feb 11, 2013 7:59 pm

Use an LDO 5V regulator (Low Drop Out) and you can easily use 6 AA NiMH batteries that range from 8.3V to 6v. They have the same inefficiencies as any other linear regulator but will be able to function down to the floor on a 6 pack of most rechargeable cells.

A better type of regulator is something like this:
http://www.pololu.com/catalog/product/2118

A little switcher that can supply a bit above 1A and will not eat up the batteries trying to heat the room. I use a similar switcher in my design and get an easy 5 hours with WiFi dongle from 6AA NiMH batteries. Little heat is generated and I get solid 5V all the way down to full discharge on the batteries.

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