Reverse polarity protection 2 (CB22140E)

This circuit has an improvement over the previous one as it also has an LED indicator for correct polarity.

AM Receiver (CB7490E)
We found this 4-transistor receiver for the AM MW range in a 1960 transistor manual from Sylvania....
Current Sensor with AD Converter (CB5247E)
This 16-bit circuit was found in a 2005 Linear Technology application manual. The circuit uses...
Two Transistor Metronome (CB13959E)
The circuit is from an English publication from 1970, but it can be assembled with more modern...