This circuit is from NASA documentation from the 1980s. The circuit shows how to obtain a stable optical coupler system. The circuit can be used as a shield.
This circuit was obtained in a 90’s Popular Electronics. The operators admit equivalents such as...
Found in a May 1988 Radio Electronics issue, this is a Smitt trigger that requires a symmetrical power...
Suggested by the 90s ARRL Handbook edition, this circuit aims to reduce or cancel noise at the...