Found in Popular Electronics from the 1980s, this circuit uses two operational amplifiers from that time. The circuit has frequency and symmetry adjustment.
This lockable two-position servo control system was found in documentation from the 1990s. The...
The battery charger shown in the figure uses two 60 W incandescent bulbs in series to limit the...
The accuracy of this 3-digit digital capacitor meter depends on the tolerance of the components used and...