Bart Bervoets wrote:

are fairly constant. You didn't indicate what sort of
device you are trying to power; some are much more forgiving than others.


Creative labs pc speakers in my car.


So you need a 3 ohm 5 watt resistor


And for 2 amps?
I don't really understand your calculation as i am useless in math.

Bart Bervoets


because your required voltage is so close to the supply voltage,
there isn't much in the line for a common regulator circuit to
maintain a stable regulated 9 volts
don't get me wrong, you can make a PWM (pulsed width modulated)
unit to drive a power FET with a very low on resistance to give you
a nice regulated 9 volts.
you can find DC to DC converters online, you just need to know your
wattage/amp factor of the load.
or use a dual op-amp, MOS powerfet witha few minor components and
make your self a regulated PWM supply...


--
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5