I'm investigating power options for my festival rig. I've got an extra DVD battery (12 Volt, similar to the Wal-mart battery) that I'd like to use for my external hard drive. The problem is the hard drive runs on 5 volts. Can I buy or build something that will step down the power from 12V to 5V? Can anyone here explain how to me?
Thanks.
yea..take a look at the jb3 pwer II thread....leegeddy is building a VR box...shoot him a pm for more details...but there is some info in that thread
There are losts of ways to regulate voltage. how handy are you at soldering?
1.) leegeddy power solution
2.) build your own voltage regulator from component parts.
3.) hack a fixed or adjustable car adapter.
google for:
LM7805 5V fixed voltage regulator
LM317 voltage regulator that can be adjusted to other voltages
The datasheet for the 7805 will show a circuit diagram.
a few dollars worth of parts and very simple assembly.
Quote from: Maynard G. Beatnik on January 14, 2005, 03:49:33 PM
google for:
LM7805 5V fixed voltage regulator
LM317 voltage regulator that can be adjusted to other voltages
The datasheet for the 7805 will show a circuit diagram.
a few dollars worth of parts and very simple assembly.
i prefer the LT1086 b/c it can handle 1.5 amps and is also of the LDO (low drop) variety too bad they don't make it in a surface mount package.
If the current draw is significant you'll be generating quite a bit of heat dropping from 12 >5 with a linear regulator. A lower voltage battery will help, otherwise you'll need to think about heat sinking if you make it. A car adapter is where I'd start - it's cheap and usually delivers 500-1000 mA.
I googled power consumption and found that 2.5 watts is typical.
Watts = Volts x Amps
So 500 mA should do it and the car adapter is your friend.
Another spot I just checked spec'd start up at 1000, seeking at 500 and idle at 250 mA.