This circuit was based on Maxim's MAX4374. The circuit senses the current in a 0 to 20 V line and has a timed output signal, with time given by R1 and C1. Power is supplied with 5V.
We found this transistorized AM receiver of the regenerative type of excellent quality in a...
We found this configuration in a French documentation from the 70s. It appears sometimes in this...
This receiver for an audio link by modulated light was found in a 90s Elektor. Transistors are common...