Two-tone solar buzzer (CB20493E)

This circuit was found in a 1991 publication. The transistor can be a general-purpose type.

Unijunction monostable (CB5425E)
This circuit was found in an American 1980s documentation. The transistors admit equivalents and the...
Offset Adjustment Sample and Hold (CB5958E)
We find this circuit in a 1980s documentation. The circuit can be applied to modern operators with...
10 W Amplifier (CB6175E)
This circuit is from Mullard documentation from 1969. Transistors support current equivalents. Output...