Patent ID: 7763839

Claim:
A luminous intensity level indicating device comprising: a single photoresistor connected to a single current-limiting resistor in series between a direct current (DC) power supply and ground; a plurality of voltage-dividing resistors connected in series between the DC power supply and ground; a plurality of comparators, a non-inverting node between the single photoresistor and the single current-limiting resistor directly connected to the non-inverting input terminal of each of the comparators, the inverting terminals of the comparators respectively connected to inverting nodes between every two adjacent voltage-dividing resistors of the plurality of voltage-dividing resistors connected in series; a micro control unit (MCU), the output terminals of the comparators connected to input terminals of the MCU; and an indicator connected to output terminals of the MCU; wherein the resistance of the photoresistor is capable of being altered by environment illumination and able to change the voltage at the non-inverting node between the photoresistor and the current-limiting resistor, and the output terminals of the comparators adjusted according to voltage comparison between the inverting and non-inverting input terminals thereof, and then the MCU controlling the indicator to indicate different luminous intensity level.