This precision signal rectifier was found in an Electronic Design. The components used are from that time, uncommon nowadays.
Texas Instruments ESD122 Electrostatic Discharge Diodes (ESD) can be ordered from Mouser...
This circuit was suggested in a 1976 documentation. We can use the pair BD135 and BD136 on the...
This interesting circuit found in an Elektor from the 90s controls loads in four quadrants of the driving...