Solar Panel Voltage Sensor Saved

This circuit is first a difference amplifier that filters and attenuates the input voltage. Next is a second order low pass filter with a Butterworth response: (Q=1/sqrt(2)). A third RC filter is set at the same (10 Hz) corner frequency. Input under voltage ( <20 V ) and input over voltage ( >50 V ) conditions are indicated with logic signals. The simulation can be used in interactive mode to trigger the active low voltage limits.