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.
In the figure we have an application for NLAS5113, a new device from on Semiconductor...
We found this phonographic transmitter for the MW band in a 1956 documentation. The circuit has a...
The circuit shown below was obtained from an Italian magazine Sperimentare from 1977. All...