This balance indicator for stereo amplifiers was found in an 80's Elektor. The components used are common. Zeners are 1.8 V or close to that value.
In fact, it is a night light system that automatically turns on the outside lights when it gets...
This is one of many twin-T oscillator configurations that can be found in this section and on this...
Found in 1965 General Electric documentation this circuit applies to a LASCR used as an optical...