I'm planning on doing a large project that would include an ARM microcontroller @ 50 MHz interfacing with a graphic LCD, user buttons, some sensors and some actuators (DC motors, valves) controlled through relays. I want to design a robust and durable power supply for this project that must have a 10+ years lifetime. I have a 24V power supply and I have to design the circuit that will give me 3.3V/5V and at least 1A. What protection components should I include in the circuit? Where does all this components come into place: PTCs, ferrite beads, filter capacitors, EMI filters, fuses etc.? Could you give me a block diagram of such a circuit?