Clarios is a $10 billion global company you've never heard of. Which is funny. Because you probably use its products every day both in your personal vehicles and in the trucks your fleet runs. That's ...

D1 is the voltage reference zener. Tied to this is a string of divider resistors (R2-6) that set the various fixed voltage levels. R7 & 8 form a voltage divider to that divides the battery voltage by ...