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
Use low voltage so safe. I am boring old buzzer. When use AC line, danger of leakage power in the heavy rain, 3 circuits can help you!.. .......
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.
Here is five burglar alarm circuits for you can look as idea To protect their property from thieves. simple switching, vibration systems, touch-sensitive.