How to power Rpi and peripherals with single power source?

[akki5230]

I want to power 3 devices with one dc dource,

1. Raspberry pi B+ : Input 5v dc, ~700mA

2. 7" Display : Input 12v dc, 750mA

3. Powered USB Hub

So how should I power these 3 with a single source ( want to use 12v dc power adapter from ac mains)

[pksato]

Hi,
you need a DC-DC converter to down 12V to 5V@3A, a ebay module or car cigar usb charger (with 2 ports).
1A to RPi, and 2A to usb hub.
Split 5V on two, one to RPi and other to usb HUB. May be, need to modify HUB to accept external power (cut 5V from rpi).
12V goes to display and dc-dc converter.