Jump to Step 4: Circuit diagrams - Gather everything and carefully follow the circuit diagram. other (as in picture 2 in this step) and connect it to the circuit. Hi, guys! I'm back with some more cool DIY projects. In this tutorial, I'm sharing with you my newly modified automatic night light circuit. This is. Project with circuit showing relay control through LDR for auto night lamp project.
|Published:||16 September 2015|
|PDF File Size:||20.7 Mb|
|ePub File Size:||30.98 Mb|
The voltage is divided into two voltages because resistor R1 and LDR are connected in series.
At day time, the peak voltage is less than breakdown voltage the SCR will remains off. We know that SCR is only operated in positive half cycle as a result the intensity of bulb will reduce but it will boost the lifespan of bulb.
When LDR1 is illuminated with ambient light in the room, its resistance remains low, which keeps automatic night light circuit pin 2 of IC2 at a positive potential.
Automatic LED Night Light Circuit - Codrey Electronics
Circuit operation Advertisement In automatic night light circuit darkness, the specified LDR has a resistance in excess of kilo-ohms.
When the resistance of LDR1 increases, a short pulse is applied to trigger pin 2 of IC2 via resistor R2 kilo-ohms.
How the Automatic night light circuit works? To be sure that our Automatic night light circuit will works fine, we use a phototransistor.
At day time the resistance of the LDR will be low and so do the voltage drop across it, the transistor Q1 will automatic night light circuit in the conducting mode. When darkness falls the resistance of LDR increases and so do the voltage across it.
This makes the transistor Q1 OFF.
The high output of the comparator provides the necessary forward bias to the base-emitter junction of the transistor T1. Thus T1 jumps from cut off to saturation state and collector current flows. This collector current energizes the relay coil.