This circuit was found in an American documentation from the 90's. What it does is provide at the output a voltage that is the average of the voltages set for the inputs.
This circuit is from a specialized documentation in 1992 FETs. The L1 coil has 0.07 uH with...
The LM1468L can also be used. The circuit is from Motorola's Linear Interface ICs and the...
This low frequency doubler requires a 50 mV signal at the input. The circuit is from an old...