NPN and PNP transistor tester (CB22146E)

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

Thermostat (CB25467E)
We found this circuit in the June 1992 issue of Radio Electronics magazine. The sensor is a common...
Positive to negative CMOS converter (CB8854E)
This circuit converts a positive CMOS supply voltage to a negative one. We found it in a 90s...
Baxandall with CA3140 (CB11981E)
This tone control was obtained from the CA3140 datasheet, originally created by RCA. The CA3140...