This design defines a stable power architecture using a 5V 8A SMPS to drive:

• Raspberry Pi + TFT LCD
• Powered USB hub
• Arduino UNO (via USB)
• Audio interface (Mackie Onyx Producer 2-2)
• MIDI keyboard controller

Goals:

• Stable 5V delivery
• Low noise for audio
• Expandable structure
• Easy maintenance

AC 220V
→ SMPS (5V 8A)
→ DC Distribution Block
   ├─ Raspberry Pi (direct 5V)
   │   └─ TFT LCD
   ├─ Powered USB Hub
   │   ├─ Arduino UNO (USB)
   │   ├─ DAC (Onyx 2-2)
   │   └─ MIDI Keyboard
   └─ Expansion

Each device is powered independently from the distribution block.

• Pi: direct power line
• USB hub: separate line
• UNO: powered via USB only

• Set SMPS to 5.1V (no load)

Total estimated: 2.5A ~ 3.5A
→ 8A SMPS provides sufficient margin

• Mean Well LRS-50-5 (5V 10A)
• Equivalent 5V 8~10A industrial PSU

• Screw terminal block (5~10 outputs)

• Main: AWG18
• Branch: AWG20
• Small loads: AWG22

• Powered hub with external DC input

• 1000µF electrolytic
• 0.1µF ceramic

• Earth (AC) must be connected
• DC ground must follow star topology

• Do NOT power UNO via 5V pin when USB is connected
• Do NOT daisy-chain power
• Ensure proper ventilation for SMPS
• Use short, thick wires for Pi

SMPS → Distribution Block → Separate lines to Pi and USB hub
UNO powered via USB

This ensures stability, safety, and audio quality.