NPN and PNP transistor tester (CB22146E)

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

One Transistor High Power Switch (CB990E)
This circuit can handle 25 A unde a 32 V voltage using a hight power old transistor. This...
Telephone line monitor (CB10149E)
We found this circuit in a 1980s publication on telephony. The circuit uses an integrated...
Photo Astable Multivibrator (CB507)
The frequency of the square signal produced by this circuit depends on the light falling onto the...