Charger protection relay (CB26312E)

This circuit was obtained from an Elektor magazine from the 90s. The circuit is to protect batteries while charging.

Driver for AD Network (CB20162E)
This circuit is a driver for R-2R network of AD converters. We found it in manufacturer...
Locking Oscillator (CB22261E)
This circuit was found in an American publication from the 60's. The transistor is made of...
Astable Audio Oscillator (CB11993E)
This circuit produces an audio tone on the speaker or magnetic capsule. Rx must be such that added...