We found this circuit in a Signetics integrated circuit manual. The circuit detects any type of metal. PNP transistors not indicated may be BC558. The coil consists of 30 turns of wire 28 in a plastic form, 30 to 40 cm in diameter.
We found this circuit in a Signetics integrated circuit manual. The circuit detects any type of metal. PNP transistors not indicated may be BC558. The coil consists of 30 turns of wire 28 in a plastic form, 30 to 40 cm in diameter.