This circuit was obtained from a Philips documentation from 1968. The transistors can be replaced with equivalents, only with care so that the doubles are exchanged for matched pairs.
This circuit was found in Electronics Now. With it the dialing signals of a telephone are...
The circuit presented was obtained from an Electronics Now magazine from February 1995. The...
This traditional TTL configuration was obtained in a 1977 documentation. The supply must be made...