The S9V11F5 switching step-up/step-down regulator efficiently produces 5V from input voltages between 2V and 16V. Pololu 2836

Step-Down converter D36V28F6 with an output voltage of 6 V, an input voltage from 6.3 to 50 V and a maximum output current of 4 A. Pololu 3783

Step-Down converter D36V28F3 with an output voltage of 3.3 V, an input voltage from 4.5 to 50 V and a maximum output current of 4.5 A. Pololu 3781

DC-DC Step-Down Converter ME3116AM6G with an output voltage of 5 V, input voltage from 6 to 24 V and a maximum output current of 1 A. Dedicated to the M5Stack modules. M5Stack U125

Module with a single-purpose LiPo charger and Step-Up converter with an output voltage of 5 V and current efficiency up to 1 A. SparkFun PRT-14380

Step-Down converter D36V50F3 with an output voltage of 3.3 V, an input voltage from 4.5 to 50 V and a maximum output current of 9.5 A. Pololu 4090

The S9V11MA switching step-up/step-down regulator efficiently produces a finely adjustable output between 2.5 V and 9 V whether it is higher or lower than the input voltage, which can range from 2 V to 16 V.  Pololu 2869 

BMS system for five Li-Ion cells with a voltage of 21 V. It has the function of charging with balancer, discharging and over-discharge protection. The cells can be charged with continuous current up to 60 A and discharged with current up to 80 A

Pololu Adjustable 4-12V Step-Up Voltage Regulator U3V50ALV

The S9V11F3S5CMA switching step-up/step-down regulator efficiently produces a fixed 3.3 V (default) or 5 V (selectable) output whether it is higher or lower than the input voltage, which can range from 2 V to 16 V. (Note: minimum start-up voltage is 3 V, but it operates to 2 V after that.)

DC-DC Step-Down converter module with 5V output voltage and 1A output current. The module can be a replacement for the popular LM7805 regulator.

BMS system for four Li-Ion cells with a voltage of 16,8 V. It has the function of charging with balancer, discharging and over-discharge protection. The cells can be charged with continuous current up to 60 A and discharged with current up to 80 A

Modular power supply with a power of 3 W, input voltage from 100 to 240 V and output voltage of 3.3 V. Designed for mounting on a PCB. Hi-Link HLK-PM03

This synchronous switching step-down (or buck) regulator takes an input voltage of up to 40 V and efficiently reduces it to 6 V with an available output current of around 15 A. Pololu 2882

DC-DC Step-Down converter module AP63203 with an output voltage of 3.3 V, an input voltage of 3.8 to 32 V and a maximum output current of 2 A. SparkFun COM-18357

Step-Down DC-DC converter module based on the D24V150F12 chip. Input voltage 14.5 ... 40V, output voltage 12V (max 15A). Pololu 2885

This powerful boost regulator efficiently boosts input voltages as low as 2.9 V to a higher, adjustable output voltage between 9 V and 30 V while allowing an input current as high as 5 A.

Modular power supply with a power of 3 W, input voltage from 100 to 240 V and output voltage of 5 V. Designed for mounting on a PCB. Hi-Link HLK-PM01

The LM317 + LM337 Symmetrical Power Supply provides stable and smoothly regulated symmetrical voltage for electronic and laboratory applications. Suitable for powering audio systems, preamplifiers and test projects where stable, regulated symmetrical voltage is essential. Requires consideration of proper cooling to maintain optimal operating conditions