LM2596 Adjustable Buck Supply

The blue-board buck regulator every desk has — 12 V down to anything from 1.5 V to 35 V at up to 3 A.

Difficulty: Through-hole. Estimated build time: about 45 minutes. Estimated parts cost: about US$6.00. 6-part bill of materials with live supplier pricing. An adjustable step-down switching supply built around the LM2596S-ADJ, the same regulator used in the ubiquitous blue "buck converter" modules sold by every electronics vendor on the planet.