This 3-transistor buzzer or buzzer is a classic type found in the July 1998 issue of Electronics Now magazine. The power rating depends on the output transistor.
Found in a 1980s English magazine, this trigger circuit can have different types of inputs...
This circuit was found in a Japanese publication from 1971. The circuit uses components from the...
This interesting circuit with an indicator tube powered by a transistor inverter was found in...