Found in Philips' 90s documentation, this small source can use modern transistors like the BD135 for TR4 and the BC series for the rest.
Found in a 90s Elektor, this mixer makes use of integrated circuits of the time. The supply must be...
The input resistance of this circuit is 60k and the pass band from 20 to 20kHz. The circuit is...
This circuit is from a publication on Motorola triacs from 1975. In it we have the way to fire a...