@The Mechatronic Engineer I think you could just use an AND logic gate. One input terminal connected to the photoresistor and the other constantly powered.
I was confused at the last example. But I think I get it. Voltage -> Photo resistor -> Lamp ->Set resistor->ground. As light decreases, resistance in photo resistance increases. As the resistance increases, the photo resistor will draw most of current, leaving the lamp with no current/power. If light increases, resistance goes down in photo resistance, giving power to lamp(on).
V = IR , as r increase, so does the voltage, meaning as it gets darker, the resistance increase and voltage increase too, so for example a bulb needs 5 v to operate but v was less as r was less during day time say 1 v or less which could be some faint light though. But you get the point now ?
i m confusing when at night there is no light to excite electron. than there is no increase in conductivity.. how to used to turn on the light at night
I believe a contrasting example has been given in the end. Actually when the light falls on photo-resistor the resistance increases which blocks the flow of electrons. And when it is covered(in dark) there is free flow of electrons. hope this helps..!!
It is called current divider system. An electric current will flow trough the smallest resistance than the big ones. In this case, we use two type of resistors, a constant one and LDR. Simply the lamp connected to the constant one, and will get the less resistance than the LDR when night comes out. And the current will flow trough it.
Permisi Pak saya mau bertanya seberapa efektif ldr mendeteksi intensitas blue light? Ini pertanyaan buat sy pada saat sidang kemarin, mungkin bisa bntu jawab
