Similar to other circuits found in this section, this circuit is from a 1996 Electronics World; FET is general-purpose and the output circuit must be resonant at 100 kHz.
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...