This circuit was found in a 90s Electronic Engineering. The quadruple operational amplifier can be replaced by an equivalent. RL determines the tested resistance range.
Using the CA3140 in the figure we have a comparator that goes low in the window voltage space. The...
This circuit is found in a 2011 technical publication from Texas Instruments. It is an amplifier for...
In this circuit, the LED lights up when the current is such that multiplied by the resistor value...