I have build a dual power supply for an analog synth (see image below).
The input source is a 12 VAC - 1.7A adapter. It is based on the Wall Wart power supply from Music from Outer Space.
Now I would like to include a 5V output to drive one or more Arduinos. If I expand the power supply with a voltage regulator (LM7805) in parallel with the LM7812 regulator, would this work?
I expect that the LM7805 regulator will be less efficient as it has to bring the voltage down from 12V to 5V and will produce more heat. Therefore, I've attached all voltage regulators to heat sinks.
Might it be better to exchange the LM7805 linear voltage regulator with a switched voltage regulator? The advantage being that it is more efficient and produces less heat, while the noise might increase. I do not intend to use batteries, so efficiency is less important, and I expect that the Arduino will not take much current.
An additional question: Have I placed the fuses F1 and F2 at the correct position in the circuit?