This shield circuit with an optical coupler was found in an 90s EDN. The circuit can be used with voltages from 0 to 600 V with the indicated component values.
This configuration, which does not have a very high Q, uses a 741 operational amplifier, but other...
This circuit is from the 70's by A. Fanzeres. We kept the original text. It has already been said...
We found this circuit in an old English publication. The resistor not indicated can be 2k2 and the...