Automotive Fuse Monitor (CB26299E)

We found this simple car fuse monitor circuit in a William Sheets. The LED lights up when the fuse blows.

Transistor Flip Flop (CB20130E)
This flip-flop circuit with general purpose transistors was found in American documentation from...
Collector Variable Current Transistor Tester (CB19465E)
We found this dynamic tester for transistors with variable collector current in a publication in...
Moisture Detector (CB22049E)
We found this sensitive moisture detector in an old documentation. The circuit uses a common JFET,...