AC DC Indicator (CB22450E)

We found this circuit in Popular Electronics from 1992. The circuit uses general purpose transistors that admit many equivalents.

Tilt indicator (CB9492E)
This indicator circuit used and game machines (arcades) to indicate that the machine is being...
Silk Screen Printing Timer (CB4652E)
If the reader still uses silk screen printing tables this is an interesting circuit found in a 1994...
Common Emitter Stage (CB22224E)
This amplifying step was found in an old American publication. The transistor is made of germanium and...