Obtained from an English publication in the 1980s, when a weather station operated in that country at 60 kHz, this circuit employed only two general-purpose transistors.
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...