This is a precision half-wave rectifier, suggested by Texas Instruments. Diodes are commonly used, and resistors can have signal values. The power supply must be symmetrical.
This circuit uses old germanium transistors because it was found in an old magazine from 1973....
This logic level indicator also indicates the presence of pulsating signals through a third LED. It...
This circuit is from the 1990 Motorola Linear Databook, which can be developed with more modern...