Found in a 1980s manufacturer documentation, this circuit can be used as an optical shield. The integrated circuit is from the era and modern equivalents can be tried out.
We found this oscillator in a publication for radio amateurs from the 70s. The circuit generates...
We found this circuit in a 1982 publication, but all the components used are still common in our...
We found this circuit in a 1976 technical documentation, but it can be assembled with modern...