Found in a Popular Electronics from the 90s, it applies to the old answering machines that used tapes. It emits a warning beep on the drive.
This circuit was found in a European documentation from 1964. The circuit makes use of components of...
We found this circuit in the Linear Applications Handbook of the National Semiconductor of 1994....
This interesting circuit, found in a European publication from the 90s, has two control channels for...