This circuit was found in an 80s Hands On Electronics. It senses the water level in a reservoir by driving a pump when needed.
This timer for long time intervals is from the 1990 Motorola Linear Databook. The setting applies...
The output voltage of the circuit shown in the figure is approximately 7.0 V for a 15 V supply...
Suitable for recovering tape recorded media from a common tape player mechanism, this circuit is...