The circuit diagram of dual tone train horn circuit has been described here. Here in this circuit, the core part is the timer IC NE 556. This NE 556 IC is the combination package of two NE 555 timers that work independently. Here the push button switch S1 is used to start the horn. A 9V DC power supply or battery is used here for powering this circuit.
- Use a good quality PCB or common board to assemble this circuit. Constructing a bread board prototype is recommended.
- In this circuit, two NE 555 timers connected in cascade can be used instead of NE 556.
- This circuit is simple and low cost but works greatly.