Motor Bike Brake Horn

The circuit can be operated from 4.5V to 12V DC or direct from the brake point of the motor-bike, Resistor R7 should be replaced with 1-ohm. 1/2W in case of an 8-ohm speaker. T5 is a driver transistor. C3 polarity can be reversed for a sudden off of the circuit.

The sound produced is like “Kiun, Kiun”.

circuit diagram of motor bike brake horn


Resistors (all ¼-watt, ± 5% Carbon)

R1, R7 = 2.2 KΩ

R2, R4 = 820 Ω

R3, R5 = 470 Ω

R6 = 4.7 KΩ

R8 = 10 KΩ

R9 = 4.7 Ω, 0.5W


C1 = 22 µF/25v

C2 = 4.7 µF/63V

C3 = 100v/16V

C4 = 0.047 µF

C5 = 0.01 µF


T1 – T4 = BC148B

T5 = SL100


LS1 = 4Ω speaker

7 thoughts on “Motor Bike Brake Horn”

  1. it is a very good project suggetion for seriousness about any one on the road who riding or walking ,also for awairness of traffic.can you send me the circuit digram.

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