Bike left right indicator Using NPN Transistor BC547

Circuit Description:

1. NPN Transistors (Q1, Q2):
   • Q1 is for the left turn indicator, and Q2 is for the right turn indicator. Both transistors act as switches.
2. Resistors (R1, R2, R3, R4):
   • R1 and R2 are connected to the base of Q1 and Q2, respectively, for biasing the transistors.
   • R3 and R4 are current-limiting resistors for the LEDs.
3. LEDs:
   • One LED is connected to the collector of Q1 for the left turn indicator.
   • Another LED is connected to the collector of Q2 for the right turn indicator.
4. Switch:
   • The switch is used to select between left and right turn signals. When the switch is pressed to the left, the left turn indicator is activated. When pressed to the right, the right turn indicator is activated

How It Works:

1. When the switch is pressed to the left, Q1 (left transistor) is biased, and the left indicator LED lights up.
2. When the switch is pressed to the right, Q2 (right transistor) is biased, and the right indicator LED lights up.
3. The transistors act as switches, allowing current to flow through the corresponding LEDs when biased.
4. The resistors (R1, R2) limit the current flowing into the bases of Q1 and Q2.
5. The resistors (R3, R4) limit the current flowing through the LEDs.
6. The switch determines which turn signal is activated, creating a left-right indicator system for the bike.