The very small step-down 6 V, 2.5 A synchronous inverter can be supplied with voltage up to 36 V, dimensions: 17.8 mm x 17.8 mm. Pololu 2859

Pololu 5V Step-Up/Step-Down Voltage Regulator S18V20F5

Step-Down converter with an output voltage of 5 V, an input voltage of 6.5 to 16 V and a maximum current of 4 A

The trigger module is designed for chargers PD 2.0 and PD 3.0. It is equipped with a USB type C input and a USB type A output. It enables powering devices with 9 V or 12 V and testing chargers. PDC005

DC voltage converter with adjustable and stabilised output voltage from 0.5 V to 32 V. It can handle loads up to 4 A and has an output of up to 50 W. It features a colour display and a handy user interface. Fnirsi DC/DC converter 50W

This synchronous switching step-down (or buck) regulator takes an input voltage of up to 38 V and efficiently reduces it to 5 V with an available output current of around 9 A.

A simple DC power supply with an output voltage of 12.6 V DC and a current of 10 A. The device can be powered with a voltage of 8 to 36 V DC. It can be used to charge Li-Ion batteries, it will also work well for powering devices such as LED lighting. SparkFun PRT-18722

Step-Down DC-DC converter module based on the D36V6F12 system. Input voltage 12.2.50V, output voltage 12V (max. 600mA). Pololu 3796

The MyoWare Power Shield is designed to take two standard CR2032 coin cell batteries to power the MyoWare Muscle Sensor. We have made this board in a way that the coin cell batteries are connected in parallel for extended capacity at a nominal 3.0V. DEV-13684

Step-Up converter module XL6009 with adjustable output voltage from 1.3 to 35 V, input voltage from 3.8 to 32 V and a maximum output current of 3 A

The compact (0.4″ × 0.5″) D24V5F9 synchronous buck voltage regulator takes an input voltage of up to 36 V and efficiently reduces it to 9 V while allowing for a maximum output current of 500 mA. Pololu 2845

This small synchronous switching step-down (or buck) regulator takes an input voltage of up to 38 V and efficiently reduces it to 9 V. The board measures only 0.7″ × 0.7″, but it allows a typical continuous output current of up to 2.5 A. Typical efficiencies of 85% to 95% make this regulator well suited for powering moderate loads like sensors or small motors.

Step-Up converter with an output voltage of 12 to 80 V, an input voltage of 8 to 60 V and a maximum current of up to 20 A

This compact (0.4″ × 0.5″) switching step-down (or buck) voltage regulator takes input voltages up to 50 V and efficiently reduces them to 9 V while allowing for a maximum output current of 600 mA. It has a very low dropout, so it can be used with input voltages that are within a few hundred millivolts of its output.

DC-DC Step-Up / Step-Down converter module. It has an input voltage of 6 to 35 V and an output voltage of 1 to 33 V. The current efficiency of the inverter is 0.05 to 5 A. DFRobot DFR0946

This small synchronous switching step-down (or buck) regulator takes an input voltage of up to 36 V and efficiently reduces it to 7.5 V. The board measures only 0.7″ × 0.7″ yet delivers a typical continuous output current of up to 2.4 A and features reverse voltage protection.

The compact (0.4″ × 0.5″) D24V5F2 synchronous buck voltage regulator takes input voltages between 3 V and 36 V and efficiently reduces them to 2.5 V while allowing for a maximum output current of 500 mA. This regulator offers typical efficiencies between 80% and 90%. The pins have a 0.1″ spacing, making this board compatible with standard solderless breadboards and perfboards.