7-segment display driver (CB20551E)

We found this circuit in English documentation from 1996 for PCs. The circuit is for common cathode display.

Bandpass Filter (CB6731E)
Found in a 1967 documentation this circuit can be applied to any operational amplifier. Components...
Complementary Mini Amplifier (CB970E)
This simple circuit was found in the Spanish magazine “Todo Electronica”, in an edition of 1996....
Audio Frequency Meter (CB20477E)
Found in a Popular Electronics from 1992, this circuit uses a PLL567 in an audio meter bridge that...