This simple audio signal tracer or follower can be made with a BC548 instead of the original transistor. The output is made in a small crystal phone. The power can be from 5 to 9V.
This non-inverting AC amplifier was found on a Popular Electronics. The setting applies to any...
This circuit uses a piezoelectric transducer to produce sounds like a buzzer. Frequency is...
The circuit shown in figure 1 is suggested by Maxim (www.maxim-ic.com) and makes use of the...