Testing of thermistors and SCRs (CB21391E)

This circuit was found in an old American manual. It is intended for testing SCRs and thermistors using indicator lamps.

OC71 and OC72 amplifier (CB18853E)
This amplifier with old germanium transistors is from a 1957 documentation. The power is a few...
Germanium Transistors 200 mW Amplifier (CB14761E)
This circuit is from the 1960 Mullard transistor reference manual. The driver and output...
Stepper motor control (CB20556E)
Using the well-known SAA1027, this circuit serves as interface for PC. No English documentation was found...