The sensor used in this circuit is uncommon today, however equivalent types can be tried. The comparator also supports modern equivalents. The circuit is from 80's documentation.
This circuit has a gain of 34 dB and a good power to be used as an audio booster in cars. The...
This circuit was obtained from Dutch documentation from 1967. It uses transistors of the time...
Found in an Electronic Design this circuit controls a headlamp by triggering a time determined by the...