This circuit was found in the February 1990 issue of Radio Electronics magazine. The gain is given by the capacitors according to the table next to the diagram.
This circuit monitors extra-low frequency (ELF) fields. We found it in an American documentation from the...
We can use any type of resistive transducer with central resistance in the range of 10 k ohms to 1...
This circuit controls two lamps so that when one increases in brightness the other decreases. The...