The operational amplifier and the sensor used in this National Semiconductor circuit are not common today, but the configuration can be adapted to use current components.
This circuit is from a documentation from the 70s. The circuit uses logic gates of the time, which...
We found this circuit in the October 1988 Radio Electronics magazine. The circuit is still current...
This CMOS logic-based circuit was found in the April 1974 issue of Radio Electronics magazine. The circuit...