Simple reversal of photoresistor (represented by 100ohm resistor and NO pushbutton), through use of standard NPN transistor and a pair of 1Kilo-ohm resistors.
- When the NO pushbutton is inactive, this indicates darkness, where there is maximum resistance in the photoresistor.
- When the NO pushbutton is active, this indicates light activation, where there is the minimum resistance in the photoresistor.
The same effect can be achieved by deleting the pushbutton and manually changing the resistance value of the 100ohm resistor (lower left). a smaller value indicates light and a higher value indicates darkness (in this circuit).
