3.3V PSU Update

I've configured the PSU I got a while back.  This is needed for the  5.8GHz video transmitter from Range Video.

It was pretty straightforward to assemble.  I put a JST connector on the input and output, desoldered the 12V pad, and soldered the 3.3V pad.  I wrapped the whole thing in a 3/4'' shrinktube, but a 1/2'' would have been better.

I'm not sure what the signal line is for.