You can do this:
Take ≈230V/8V transformer rated for ≈25VA, use rectifier bridge and smoothing capacitor ≈2200µF ..
Then use 2 step-down switching voltage regulators: one for 5V one for 3.8V ..
A good candidate for this job could be the LM2576, and in its data sheet you will find all info on how to use it .. **broken link removed**
read the TOP232 and similar search google top232 and download the data sheets, the examples is very easy and multiple circuits for desing an power transformer feriite material