Found in a 90s American documentation, this circuit that was used in cars of the time, detects low temperatures and light by activating a warning relay.
In the figure we show another interesting application for integrated circuit 4001. This circuit...
This audibility or loudness control for sound equipment is from 1992 documentation. The circuit uses...
This circuit was found in an application note of the LTC1164 from Linear Technology of the 1990s....