Micro metronome (CB20743E)

This simple CMOS metronome circuit can be mounted in a small box, providing both sound and light sources.

Overvoltage protection (CB8360E)
Found in a 1960 General Electric documentation, this crowbar circuit blows the fuse in case of...
Crystal Tester (CB24174E)
This circuit was originally designed for testing crystals used in color televisions, but it works...
Test circuit with bridge (CB22530E)
This bridge-biased transistor test circuit measures gain in the range 0 to 300. Circuit is from...