NPN and PNP transistor tester (CB22146E)

This simple transistor tester was found in old English documentation. Suitable for general purpose transistors.

Transistorized Intercom (CB11211E)
This circuit was obtained in an old magazine from the 1970s. The circuit can still be assembled with...
Transistor test (CB7381E)
This circuit was found in a Popular Electronics from the 90s. Transistors are general purpose...
Biestable Sound Switch (CB5991E)
This biestable vox circuit was found in an old documentation. The circuit makes use of components of...