This circuit was found on an old EDN and can be used as a shield. Optical couplers are from the era and modern equivalents can be used.
Found on Popular Electronics from the 1990s, this oscillator uses a general purpose transistor. The...
This circuit was obtained from National Semiconductor documentation from the 1990s. The circuit has a...
We found this circuit in a 2005 Linear Technology manual. Observe the component values and...