The indicator for this circuit is a 0 to 1 mA milliammeter. The operational is from the 70s, when the circuit was published. Modern equivalent can be used.
This circuit was found in the February 1980 issue of Radio Electronics magazine. The digital...
We found this circuit in a Motorola manual. The circuit has the capacitor charging at 15 to 30 V,...
This circuit has a high input impedance and low output impedance, serving as an adapter for...