Freeze Alarm (CB14454E)

The circuit of a 1968 publication can be implemented with more modern transistors such as BC548 for NPN and BC558 for PNP.

Peak Voltage Detector (CB5157E)
We find this circuit in an old American manual from the 80's. The circuit has a memory that keeps...
Precision Diode (CB14122E)
The circuit suggested by National Semiconductor in its 1994 Linear Applications Handbook,...
VHF and UHF switch with diodes (CB9227E)
This simple circuit for switching RF signals was found in an RF Design from the 90s. The circuit...