This signal conditioner humidity sensor was found in a 1980s Linear Technology documentation. The circuit uses components from the era that can be designed with modern equivalents.
In the figure we have the simple way to obtain a digital inverter using a general-purpose...
This circuit works with only 1.5 V and can be powered by a solar panel. The circuit is from 1991....
This circuit was found in a 1969 EEE. The circuit uses transistors from the era that can be...