Light-sensitive sensor

 It lights by day

 
 

Shematic with a prototype

 

When light falls over the light-dependent resistor transistor starts conducting and LED diode lights  

 

When it gets dark or you cover light-dependent resistor, then transistor doesn't conduct and LED diode doesn't light 

 It lights at night

 
 

 Shematic with a prototype

 

Shematic

 

 When light falls over light-dependent resistor, transistor doesn't conduct and diode doesn't light

 

When it gets dark or you cover light-dependent resistor, transistor starts conducting and LED diode lights 

 Elements

 
 

Transistor, LED diode (lights) and resistor

 

 LED diode and resistor

 

 Light-dependent resistor - LDR

 

Variable resistor 

 

Variable resistor and switch

 

 Power suplay

click to open Lesson 2