This circuit was found in a 90s Radio Electronics. It is intended to amplify the sound channel of analog televisions of the time. The integrated circuit used is uncommon today.
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...