This amplified speaker is from a Radio Electronics from September 1988. The power integrated circuit is from that time and the other components are still common today.
This circuit consists of a test oscillator for medium and high power NPN transistors. For PNP,...
This is a complete version of the previous circuit, with several scales and two transistors, one...
Found in a 1965 Electronic Design, this circuit makes it possible to select signals with an...