This circuit is from a 1974 Ferranti transistor manual. The circuit is analog, and the components used are period types.
In the figure we have a voltage / frequency converter circuit that can be used as a transducer interface...
Using an integrated voltage regulator as a reference, we can control several power transistors of type...
This circuit was found in a 1995 documentation. It deactivates a power supply in the event of a...