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 causes an LED to blink when night falls. Sensitivity is set at R1 and the blinking...
This amplifier with the AC187 and AC188 pair and the CA3130 integrated circuit was found in an...
This circuit is from a 1998 Electronics Now and can be easily assembled since it uses a common...