This circuit consists of a stereo audio compressor. We found it in Radio Electronics magazine from October 1968. The circuit uses an opto-coupler made with a neon lamp and LDR.
This circuit is from a 1990 publication, but the idea can be used in a current project to supply...
This interesting source of very low voltage for reference finds applications in the...
Found in Electronics Today International in the 90s, this circuit turns an operational on and off...