This circuit simulates an American siren and can be found elsewhere on this website and section. The circuit is from a 90s documentation. Preferably, the signal should be applied to an amplifier.
This traditional detector configuration is from an old publication where the MC1555 is the...
This two-transistor emitter-coupled oscillator circuit with capacitive feedback was found in the...
If the reader is skilled, he can mount this spy micro-transmitter with SMD components and obtain an...