Introduction to BC547

Hello everyone! I hope you all will be absolutely fine and having fun. Today, I am going to give you a detailed Introduction to BC547. It is an NPN bipolar junction transistor (BJT), mainly used for switching and current amplification.

Its maximum current gain is around 800. So, let’s have a detailed overview of BC 547.

Introduction to BC547

• BC547 is a 3-Terminal NPN Bipolar Junction Transistor(BJT), mostly used for switching purposes and current amplification.
• BC547 Pins(Terminals) from left to right are called:
  • Collector.
  • Base.
  • Emitter.
• Depending on the voltage applied at Base Terminal, BC547 can operate in two states, named:
  • Forward Biased.
  • Reverse Biased.

BC547 as Reverse Biased

• If Base Terminal is connected to the Ground(0V), Collector and Emitter will act as an open switch and the transistor is said to be acting as Reverse Biased.
• In a Reverse Biased State, no current will flow through the transistor.

BC547 as Forward Biased

• If a HIGH signal(normally 5V) is provided at the Base Terminal, Collector and Emitter will start acting as a closed switch and the transistor is said to be acting as Forward Biased.
• In Forward Biased State, the current will start flowing from Collector to Emitter.
• The maximum Collector current limit of BC547 is 110mA, so the load must be lower than that.

• Now let’s have a look at the datasheet of BC547:

BC547 Datasheet

• If you want to get in-depth knowledge about any electronic component, then you should read its datasheet.
• You can download BC547 Datasheet by clicking the below button:

• Now, let’s have a look at the pinout of BC547:

BC547 Pinout

• BC547 Pinout consists of 3 pins in total, named: Collector(C), Base(B) and Emitter(E).
• All of these three pins along with their symbols are shown in the below table:

BC547 Pins Configuration

• The properly labeled pin configuration diagram of BC 547 along with its animation is shown in the figure given below.

• In the last section, we will design a Proteus Simulation of BC547, which will give you a better understanding of How to use these pins of BC547.

BC547 Transistor Working

• As we know BC547 is an NPN transistor, so in its design, a P-region(Base) is sandwiched between two N-type regions.
• At the border of the P and N, a depletion region is created, which blocks the flow of charge carriers from one region to another.
• When the input voltage is applied at its Base terminal, some amount of current starts to flow from the base to the emitter and controls the current at the collector.
• The voltage between the base and the emitter (VBE), is negative at the emitter and positive at the base terminal for its NPN construction.
• The polarity of voltages applied for each junction is shown in the figure below:

BC547 Ratings

• The current, power and voltage ratings of BC547 along with their values and System International (SI) units are provided in the table shown below.

• Moreover, the storage temperature, as well as operating temperature for the transistor BC 547, is also given in the table shown above.

BC547 Thermal Characteristics

• The thermal characteristics associated with BC 547 are provided along with typical values, in the table shown below.

BC547 Applications

• There are a lot of applications associated with BC547, a few of the major applications are given below.
  • BC547 can be used for switching purposes.
  • We can also use it for amplification purposes.

BC547 Proteus Simulation

• I have made a simple Proteus ISIS simulation using BC 547 for the control of the DC motor.
• The screenshot of the simulation is shown in the figure below.

• The running form of the simulation is shown in the figure below.

• By pressing the button encircled in the figure above, you will be able to observe the working of the DC motor.
• I have made another simulation for DC motor control using Arduino UNO and BC 547.
• The simulation’s screenshot is shown in the figure below.

• The source code for the above simulation is given below.

int MotorInput = 2;
int MotorOutput = 7;

void setup() 
{
    pinMode(MotorInput, INPUT_PULLUP);
    pinMode(MotorOutput , OUTPUT);
}

void loop() 
{
    if(digitalRead(MotorInput) == HIGH)
    {
      digitalWrite(MotorOutput, HIGH);
    }
    if(digitalRead(MotorInput) == LOW)
    {
      digitalWrite(MotorOutput, LOW);
    }
  
}

• The running form of the simulation is shown in the figure below.

• First of all, you need to change the logic state from 0 to 1, after uploading the hex file, the motor will automatically start to rotate.

That is all from the tutorial Introduction to BC547. I hope you enjoyed this exciting tutorial. If you are facing any sort of problem regarding anything, you can ask me in the comments anytime you want, without even feeling any kind of hesitation. I will try my level best to solve your issues in a better way, if possible. Our entire team is also 24/7 there to entertain you. I will explore further hardware equipment in my upcoming tutorials. So till then, Take Care 🙂