This circuit is from a 1968 documentation using one of the first integrated circuits available at the time, the TAA370. The circuit is powered by 1.3 V using a 200 ohm handset.
This ultra-low power metronome was found in a 1991 documentation. The output transistor is general...
This circuit is based on an operational amplifier that must be powered by a symmetrical source. The...
The Texas TL783 integrated circuit is a three-terminal high voltage regulator with a wide range of...