We found this circuit in the Electronics Experimenter Handbook magazine from 1993. L1 has 2 = 2 turns of 28 or 30 wire in the shape of 0.5 cm without core. The range reaches a few tens of meters.
This circuit was obtained in documentation on medical applications from 1966. The circuit is used in...
This circuit, which appears from other sources on this site, converts a voltage into a current....
This interesting circuit makes the needle of a microammeter oscillate at random, imitating a...