Based on Texas Instruments documentation, this circuit is based on the BQ2000 a circuit used to power LEDs. The circuit can be used with lithium-ion batteries.
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...