Circuit Documentation

Summary

This circuit is designed to control a 12V relay using a light-dependent resistor (LDR) and a BC547 transistor. The circuit is powered by a 18650 battery. The LDR senses the ambient light level, and based on this, the transistor switches the relay on or off.

Component List

1. Photocell (LDR)

   • Description: A light-dependent resistor that changes its resistance based on the ambient light level.
   • Pins: pin 0, pin 1

2. BC547 Transistor

   • Description: A general-purpose NPN transistor used for switching applications.
   • Pins: collector, base, emitter

3. Resistor

   • Description: A passive electrical component that provides resistance to the flow of current.
   • Pins: pin1, pin2
   • Properties:
     • Resistance: NaN Ohms

4. 12V Relay

   • Description: An electromechanical switch that is activated by an electrical signal.
   • Pins: +, -, C, NC, NO

5. Battery 18650

   • Description: A rechargeable lithium-ion battery.
   • Pins: +, -

Wiring Details

Photocell (LDR)

• pin 0 is connected to:

  • 12V Relay pin +
  • Battery 18650 pin +

• pin 1 is connected to:

  • BC547 Transistor collector
  • 12V Relay pin -

BC547 Transistor

• collector is connected to:

  • Photocell (LDR) pin 1
  • 12V Relay pin -

• base is connected to:

  • Resistor pin2

• emitter is connected to:

  • Resistor pin1
  • Battery 18650 pin -

Resistor

• pin1 is connected to:

  • BC547 Transistor emitter
  • Battery 18650 pin -

• pin2 is connected to:

  • BC547 Transistor base

12V Relay

• + is connected to:

  • Photocell (LDR) pin 0
  • Battery 18650 pin +

• - is connected to:

  • Photocell (LDR) pin 1
  • BC547 Transistor collector

Battery 18650

• + is connected to:

  • Photocell (LDR) pin 0
  • 12V Relay pin +

• - is connected to:

  • Resistor pin1
  • BC547 Transistor emitter

Code

There is no microcontroller code associated with this circuit.