Hi everyone. I would like to ask about this light sensor using not gate circuit. I use LDR as an input and a LED as an output. I have tried this circuit in Proteus, and it works. When the LDR 'off', LED turns on, and vice versa.
But i don't really understand about the working principle of this circuit.
This is my assumption :
if LDR is off, Q5 will be 'open' cause there is no current flow. So , current will flow from R5 to R9 to Q6 , Q6 is 'short' because basis get the current flow from battery , hence LED is ON.
if LDR is on, Q5 is short, so the current from the battery will not flow through 1K because it will choose a resistance free way. Hence, the LED is OFF.
Is my assumption correct? Please tell me what you guys think? I will appreciate that so much :)
*sorry for my bad english , i'm still learning :)