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.
The purpose of this 1965 Radio Electronics circuit is to help observe cycloid waveforms on an...
This circuit was obtained from a 1976 NASA handbook. The circuit makes use of an operational of the...
In the figure we have the way to use a common LED as a light sensor. The operational power supply...