Found in Analog Devices documentation, this circuit is used in measurement bridges to linearize the signals when approaching equilibrium. Formulas are given next to the diagram.
The load controlled by this circuit depends on the triac used. The circuit is from Electronics Now magazine...
This amplifier uses a 1975 integrated circuit, which is uncommon today. The circuit has a gain of 30...
Found in a 1968 Novel Electronics Circuit, this circuit compares two light intensities using...