Found in 90's Electronic Engineering this circuit can be used to measure phase angles between two signals from 0 to 180 degrees. The components used admit modern equivalents.
This circuit was found in Motorola documentation from 1966. The lamps are according to power and...
This circuit divides the grid 60 Hz frequency to obtain 20 Hz to drive mechanical watches used at...
We found this circuit in a Mullard manual from 1960. The transistor is a phototransistor of the...