Portable 3.3v regulator for a 9 volt battery?

I've seen a great deal of portable breadboard PSU's that output 5 volts from a 9 volt battery, and I find these fantastic! However, I was curious...is there any way to refine this futher down to get a steady 3.3 volts? I would like it to be something close to the system that sath02 has made here as it not only better suites my nees, but makes sense to me.

Thanks in advance!

Yes. Buy a 3.3V regulator ! Change the 7805 for a 7803.

That said, its HORRIBLY inefficient, and you'd really be better buying a DC-DC converter like this http://www.dimensionengineering.com/products/de-sw033
vricsi945 years ago
If you want to build something similar, then you could use the 78l33 voltage regulator. It's totally portable. However, I agree with steveastrouk in the question of its efficiency.