This circuit supplies a continuous voltage at its output, which is the peak value of the alternating input voltage. The circuit is from a 90's EDN, making use of Maxim integrated circuits of the time.
This circuit was found in Motorola documentation from the 1980s. PUTs are not common components...
This low distortion circuit was found in a 1964 Electronic Design. The transistor admits...
This circuit is based on an uncommon Texas component today, as found in an American 1980s...