This circuit was obtained from an American documentation from the 90's. The transistor can be a low noise general purpose like the BC549.
This frequency modulated light transmitter is from a 1990s documentation. The circuit may use...
The basis of this circuit is an LM380 that drives a speaker that emits sound when moisture is...
This precision circuit can provide timings from 0.2 milliseconds to 3 minutes accurately. The...