This circuit was found in National Semiconductor documentation from the 90s. The circuit uses two sensors, one of which is a reference thermocouple for cold junction.
We found this circuit in 2005 Linear Technology documentation. The integrated circuit is LT1787...
We found this touch control on a Popular Electronics from 1970. The circuit makes use of an...
This circuit was found in a 1966 EEE. What it does is it converts the logic levels of 0 V and +4 V...