Found in a Philips' 1968 documentation, this circuit is slightly different from the previous one. The components are also from the era, and modern equivalents can be used.
This circuit generates a rectangular signal whose frequency depends on the electrolytic...
This circuit was found in an old publicatio n from the year 1958. The circuit controls an external load by...
This circuit that converts very low currents into voltage was obtained in the 80's used component...