XL6009 Adjustable Boost Converter

Step a 3.7 V Li-ion cell up to 12 V at half an amp with a single switching regulator — the foundation of every portable gadget that needs more voltage than its battery offers.

Difficulty: Through-hole. Estimated build time: about 40 minutes. Estimated parts cost: about US$7.20. 6-part bill of materials with live supplier pricing. A boost converter — a switching regulator whose output voltage is HIGHER than its input — built around the XL6009 IC.