We found this circuit in the April 1979 Radio Electronics magazine. Note the filter capacitor bank that can now be replaced by a single equivalent value capacitor.
In the figure we have a TTL logic interfacing circuit as CMOS logic using a 6N139 optocoupler...
The components of this filter are calculated using the formula f = 1 / RC and it can be...
The output voltage of this regulator circuit can be cut (dropping to 1.2 V) from a high level...