Found ina 1970 American documentation this fast-reading circuit uses a photodiode. Transistors support modern equivalents. The circuit can be used as a shield.
Found in a 1969 documentation, this circuit consists of a multi-oscillator with neon lamps....
This high-performance circuit was found in the 1982 SGS Linear Integrated Circuits Manual. The...
We have in the diagram another way to make the null adjustment of an operational amplifier. In...