DC-DC Step Down Converter Module LM2596 DC 4.0~40 to 1.3-37V Adjustable Voltage Regulator
Input voltage: 3.2-40V (Input voltage must be higher than output voltage 1.5V above)
Output voltage: 1.5-35V (Adjustable voltage)
Output current: Rated current is 2A,maximum 3A (Additional heatsink is suggested for this rate)
If the output power greater than 15W, the proposed combined heat sink
Per dozen price is 120Rs/piece.