Amazon.com: Eletechsup Input Voltage DC 0.7~3V Output DC 3V DC DC Boost Converter Step-up Voltage Regulator Power Supply Module (DC3V, with 2.54mm pin, 4): Industrial & Scientific
Amazon.com: 20 Pieces 3 Pins AMS1117-3.3 DC 4.75V-12V to 3.3V Voltage Regulator Step Down Power Supply Buck 800mA Module: Electronics
Amazon.com: Buck Converter, PEMENOL 5PCS AMS1117-3.3V Voltage Regulator DC to DC Step-Down Power Supply Module 3 Pins 4.75V-12V to 3.3V Voltage Linear Regulator Stabilizer Step Down Buck Module 800mA: Electronics
File:TS7805 voltage regulator.JPG - Wikimedia Commons
Transistor Kit, 3 Pin Terminal Postive & Negative Voltage Regulator IC Transistors Assorted Assortment Box Kit T0-220 Set, Range L7805-LM317+ Insulation Silicon Pad + Insulation Cap, Ltvystore: Amazon.com: Industrial & Scientific
Bridgold 10pcs L7824CV L7824 Linear Voltage Regulator, 1.5A 24 V 3-Pin, TO-220: Amazon.com: Industrial & Scientific
ST Micro L4940V5 Low Dropout Regulator, 5 Volt, 1.5A, 3-Pin, 9.15 mm H x 10.4 mm L (Pack of 4): Amazon.com: Industrial & Scientific