If the input voltage falls below 12 V the LED glows up. Other voltages can be monitored by changing the zener diode. The 1k2 resistor determines the current across the LED and can be changed.
If the input voltage falls below 12 V the LED glows up. Other voltages can be monitored by changing the zener diode. The 1k2 resistor determines the current across the LED and can be changed.
