Here is circuit switching regulator 5V 5A for digital circuit. Use IC LM2678-5.0 is High Efficiency 5V 5A Step-Down Voltage Regulator This is good power supply, small size and do not hot.
All about switching power supply circuit diagram and PCB
It is a great idea. but It is suitable for an old hand!
A good DC switching power supply circuit form old computer that not used. It has used powerful, durable and works great.
This is the DC switching regulator Voltage 5V at current 3A. It is make for digital circuit. The important part of the circuit is LM2673, it is 3A Step-Down Voltage…