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.
This circuit changes the dynamic range of an audio signal. The integrated circuit used in this...
This circuit uses PNP transistors that can be BC558, but if the power is reversed, BC548 can be...
We found this circuit in old documentation from National Semiconductor. The circuit makes use of a...