This simple moisture meter circuit uses for level moistness temple of the earth. Fine the value R2 give Meter read the value has 1mA. When the moistness [...]
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.