DC/DC switching regulators | TI.com
LM317
https://www.ti.com/lit/ds/symlink/lm317.pdf
Control an LM317T with a PWM signal - EDN
http://eletrica.ufpr.br/graduacao/e-books/Electronics Power Supply and Battery Charger Circuit Encyclopedia.pdf
LM2596
Regulador de Tensão LM2596 Com Display
LM137