Zapro:
retrolefty:
To OP: I would recommend a board like this anytime when powering the 'Duino from a voltage higher than 5,5V
Power Regulators & Converters for sale | eBay
Much more effecient, no extra heat!
// Per.
I'm a big fan of those Asian switching regulators, they are so useful and would be perfect for using 12v battery power with the switching regulator adjusted to 7.5 vdc output. I found them even cheaper (free shipping!) and bought five of them:
And why would you adjust them for 7,5V and burn off extra power in the Voltage regulator ? Why no set it to 5V and power the Arduino from the 5V-pin... ?
// Per.
Because the arduino folks advice against wiring +5vdc into the 5V pin.
5V.This pin outputs a regulated 5V from the regulator on the board. The board can be supplied with power either from the DC power jack (7 - 12V), the USB connector (5V), or the VIN pin of the board (7-12V). Supplying voltage via the 5V or 3.3V pins bypasses the regulator, and can damage your board. We don't advise it.
Lefty