High impedance stage (CB20564E)

This high input impedance amplifier stage was found in a 1963 documentation. The transistor germanium of the time.

Class B Amplifier Stage (CB4248E)
This typical two-transformer push-pull step circuit can be found on many small old radios and...
a Photodiode Amplifier with Trigger (CB4579E)
In the figure we have a sensor circuit that makes use of common transistors and a photo diode as...
RC Time Circuit (MSB026)
Figure 1 shows a circuit than can be used as time stage in timers, and other applications....