Copy of 12V Battery charge controller

Hello Lyndon

The voltage divider R1 and R5 fluctuate around the 2.49V reference voltage of the TL431C.
The positive feedback R3 and R4 is calculated according to the circuit hysteresis.
View Comparator using inverting input:
http://www.analog.com/en/analog-dialogue/articles/curing-comparator-instability-with-hysteresis.html
In practice, the maximum and minimum values of the output voltage of the comparator AMPOP must be considered.
The rated voltage of the lead-acid battery voltage is approximately 12.8V

Best regard

Bezerrabrasileiro