Скачать или смотреть Amazing Project to make automatic night switch using LDR and Transistor 2N3904 on Breadboard

#LDR
#Night_Switch
#Street_Light_Switch
Let's create a simple night switch circuit using a 2N3904 NPN transistor and an
LDR (Light Dependent Resistor). This circuit will automatically turn on a load (such as a light) when it gets dark and turn it off when it's daylight.

Here are the steps to build the circuit:

1. **Components Needed
**2N3904 NPN transistor
**LDR (Light Dependent Resistor)
*One 1kΩ resistor*
**One 10kΩ Resistor
**DC power supply or battery (5V to 12V)

2. Circuit Explanation
Connect the collector (C) of the 2N3904 transistor to the positive supply voltage (Vcc).
Connect the emitter (E) of the transistor to the relay coil.
Connect the other end of the relay coil to the ground (GND).
Connect the common terminal (COM) of the relay to the load (e.g., a light bulb).
Connect the normally open (NO) terminal of the relay to the positive supply voltage (Vcc).
Connect one end of the LDR to the base (B) of the transistor.
Connect the other end of the LDR to the ground (GND) through a 1kΩ resistor.
Connect the junction of the LDR and the resistor to the base (B) of the transistor

3. Opera intion
During daylight, the LDR has low resistance, keeping the transistor off.
The relay remains in the normally open (NO) state, and the load is off.
When it gets dark, the LDR resistance increases, turning on the transistor.
The relay coil energizes, closing the relay contacts, and the load (light) turns on.
4. Applications
Garden lighting
Passage lighting
Security lights
Parking lot lighting
Street lights
Glow signboards
Hoardings
Doorway lighting, and more.

Remember to connect the components correctly, and you'll have an automatic day-night switch using a 2N3904 transistor! 🌙🌞 If you have any further questions or need additional assistance, feel free to ask! 😊⁴.