Constant current source (CB20484E)

This circuit uses a current regulator from the 90's. This component is uncommon nowadays. The transistor admits equivalent.

Simple 555 Timer (CB3982E)
This configuration is suggested by Mullard (Philips) in an old manual of 555 integrated circuits....
Integrated Digital Circuits Test (CB3895E)
We found this circuit in an American documentation of the 80's, being indicated for the test of...
NPN and PNP Transistor Power Switch (CB992E)
This circuit was found in a publication of the year 1968. It uses complementary transistor to...