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.
We found this variable regulator circuit in a Radio Electronics issue from July 1984. It is one of...
The MC4741 consists of a quadruple 741. The power supply must be symmetrical, and the resistors must be...
Suggested by Sprague in the 1980s documentation, this circuit can control three-phase AC motors....