NPN and PNP transistor tester (CB22146E)

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

Automatic Headlight Switch 555 (CB24403E)
This circuit was found in February 1976, Radio Electronics magazine. The circuit is powered by 12 V...
Digital Low Pass Filter (CB13621E)
This circuit was obtained in a 1973 publication, being implemented with TTL technology. The...
One Million Hour Indicator (CB6698E)
Found in a 1969 documentation on neon lamps, it actually takes advantage of the durability of the neon...