I've got a Sony Bullet cam to fit to the bike to aid the prosecution

It comes with a little 8 x AA battery pack to run it but I'd rather run it from the bikes battery.

I assume I wont be able to run it straight from the battery due to the varience in voltage due to charging/load?

The camera needs a 12v DC input with 120mA power consumption.

Is it a regulator I need to keep the voltage constant? Anyone know a good place to get one???

Thanks in advance