Third Order Low Pass Filter (CB25264E)

This circuit was found in the December 1990 issue of Radio Electronics magazine. It was used in a home theater sound system.

Front detector (CB9688E)
Found in American documentation from the 90s, this CMOS circuit detects the source of a signal and can...
12 To 9 V Converter with Protection (CB5006E)
I found this circuit in an old English magazine from 1981, but it can still be assembled with some...
Triangular and sawtooth generator (CB21447E)
This circuit was obtained from a 1969 Electronic Design. Transistors admit modern equivalents. The frequency...