This circuit was found in an old American documentation. It can operate with signals from 40 Hz to 50 Hz and the input voltage range is from 0 to 200 mV.
The circuit presented uses Linear Technology Operationals, having been found in a 1993 manual. The...
The circuit presented with low drift is from the Motrorola LinearDatabook of 1990. The circuit...
120 degree lagged signals can be obtained with the simple configuration shown in the figure....