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.
With this circuit it is possible to use a DC buzzer (not a transducer) as an extension of the...
This circuit allows feeding a small semiconductor laser to obtain a useful resource for...
This circuit comes from a Gernsback Publications of the 90s. The circuit uses a general-purpose transistor as...