This is High power siren circuit with small PCB size, using CD40106 and four transistor TIP31-TIP32 increase current to horn speaker 20W, 4-8ohm. , and
Today I would like to introduce the simple and economical simple siren circuits. It is suitable for beginners. My son will gradually build this circuit onto the PCB layout. Look at below! 4 Circuits.
This is four siren sound generator circuit using UM3561,VR1 to take to control the frequency of oscillator circuit the internal IC, 8 ohms speaker output [....]