DS - https://www.mouser.com/datasheet/2/149/LM7812-461970.pdf?srsltid=AfmBOooQ_nzJcPlu-FnTlI5jU5ln2RB_RPVLN0U-ogi1nRWMWqJ3qpAT
WIKI - https://en.wikipedia.org/wiki/78xx