I connect LDR and PIR sensor to input of Transistor And Gate circuit and connect 4 LED 12V 1W to output . But LED is alway bright. when have no input from both sensor LED is little bright. So, I pull out input from LDR. when somebody pass PIR sensor it's more bright . And If have input from both sensor it's most bright. I want only ON/OFF LED not want little bright. how to fix it.
I connect LDR and PIR sensor to input of Transistor And Gate circuit and connect 4 LED 12V 1W to output . But LED is alway bright. when have no input from both sensor LED is little bright. So, I pull out input from LDR. when somebody pass PIR sensor it's more bright . And If have input from both sensor it's most bright. I want only ON/OFF LED not want little bright. how to fix it.
In this case you must use a comparator , comparators can't give you a linear out put it means they only can be 1 ( high ) or 0 ( low ) . ( on or off ) .
Two choices :
1-using an op amp as a comparator .
2- using a comparator ( like LM311 or ... )
I want to set LED output hight (12V) when input from LDR and PIR sensor is hight only. how to use comparator with this circuit . Can I connect LDR and PIR to opamp? or I have to connect output from TR AND gate to opamp.
I want to set LED output hight (12V) when input from LDR and PIR sensor is hight only. how to use comparator with this circuit . Can I connect LDR and PIR to opamp? or I have to connect output from TR AND gate to opamp.