Found in 90s Radio Electronics, this small transmitter has a good range. L1 is formed by 3 + 3 turns of wire 24 around a pencil as a reference.
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...