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 AC 220V siren circuit is a simple siren that use 220V AC as power supply. It is small size and use a piezo speaker cause use low power and saving.
Here is The 4 Sound effects generator using UM3561 and a few parts only. It can make siren, Ambulance sirens, Police car sirens, Fire truck siren and Space
This is police siren circuit using 555 IC, with PCB layout, using 2 IC-555 as frequency oscillators and transistor to drive sound to the speaker [...]
Suitable for beginners. Build a simple, but widely applied.
This is two tone alarm use op-amp IC, LM3900 (Quad Amplifiers). It produces the frequency of square wave in 2 level. It is high frequency and low then mix the…