This circuit was based on Maxim's MAX4374. The circuit senses the current in a 0 to 20 V line and has a timed output signal, with time given by R1 and C1. Power is supplied with 5V.
The circuit shown is from an old European publication. In it we have the way to activate a relay...
We found this circuit in a European publication from the 1990s. Transistors are still common types...
This circuit was found in an American documentation and can be added to common amplifiers of any...