LM7805 USB Power Supply

Barrel-jack 9–12 V input, regulated 5 V output via USB-A jack.

Difficulty: Through-hole. Estimated build time: about 60 minutes. Estimated parts cost: about US$4.00. 10-part bill of materials with live supplier pricing. A perfboard linear power supply that takes 9–12 V DC from a barrel jack, regulates it to a stable 5 V using an LM7805CT in a TO-220 package, and delivers that voltage through a USB-A socket.