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.
In the circuit of the figure we have the production of rectangular signals of frequencies up to...
The circuit shown in the figure is suggested by Intersil (www.intersil.com) and makes use of the...
This circuit was found in old documentation, the transistor being the modern equivalent of BC548...